Club126UK

Fiat 126 Chat => Tuning & Customising 126 Models => Topic started by: alapimba on February 13, 2011, 10:38:18 PM

Title: heat shields on a tunned engine?
Post by: alapimba on February 13, 2011, 10:38:18 PM
hello

i have a 650cc engine with a 35/75 camshaft, -35,7/28 valves -lower 2mm head, and a record monza replica exhaust, 28weber.

Should i use or remove the engine heat shields? I mean the metal "floor" that goes above the dinamo.
Also can anyone please show me where should i connect the earth strap?

Thank you
Title: Re: heat shields on a tunned engine?
Post by: DEYAN IYI on February 14, 2011, 09:36:17 AM
Hi!

I wouldn't remove that thing - bad aerodynamics and dirty engine room :) I'm not sure if it helps cooling at all.

The earth strap - buy long enough piece of it. I have it connected on alternator case (also you can fix it on one of the 4 bolts on the holder to the block but for dynamo not a good idea), then on the left wall of the engine room on the bolts of the relay. It was the easiest way to do it, without making something special. I don't like the idea to be fixed on the bolts of the engine mounting "spar".

Your tuning kit sounds lovely :D But do not spoil it with the original carb :oops:

Greetings!  :)
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 14, 2011, 10:30:01 AM
eheh i'll keep the original carb for nwo because it was the cheapest way as i already had it with me.
I'll mdo some trips like this and then improv a bit maybe with a weber 32 dcof, not sure yet...

The engine mouting "spar" is the bar that bolts on each side of the car and where the engine sits on?
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 14, 2011, 10:31:42 AM
picture of the engine:

(http://img829.imageshack.us/img829/5732/5428286598affb1efea2b.jpg) (http://img829.imageshack.us/i/5428286598affb1efea2b.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: heat shields on a tunned engine?
Post by: DEYAN IYI on February 14, 2011, 11:42:32 AM
 :D

Yes, the "spar" I mean that "bar".

'Bout the "budget"  part of the thing I can imagine :-X

Now I see, you got a 500, so if you worry about the hot air,
you can enjoy the old nice "open hood" Abarth look.

 :)
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 14, 2011, 11:45:37 AM
yeah i forgot to mention that it's a 500. but as all the mechanics is 126, including gear box :)
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on February 14, 2011, 02:13:35 PM
 :D Hi the 500 has a plain metal , non vented cover as opposed to the 126 that has deep louvres cut in the section below the dynamo & cooling housing to encourage air flow. I have fitted a 126 cover as they are interchangeable if you trim a little metal from the rear left hand corner of the cover to match the shape of the 500. The standard earth strap on a 500 is a slightly heavier duty brown wire with lugs that bolts to the underside of the dynamo mounting casting bolts. Then connects to the bodywork at the lower nearside "spar" mounting stud. See picture  [-/
Two good reasons for refitting the Weber 28 IMB carb are that you know it will fit  :D
Then it will give you a chance to get to grips with all of the mods and see how well you can get it running before you try to blow the roof off.
One thing is for sure , you are going to notice a huge change from the stock 499ccs engine you started with. Have you checked out the carb number & jet sizes  ???
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 14, 2011, 02:20:47 PM
Hello, thanks for the picture. it helped a lot.
One doubt about that cover, the deep louvres were not supposed to be on the oposite way to get fresh air from under the car?

I didn't noticed that under the dinamo i could connect anything. Not i got the idea thanks.

About the carb i didn't checked the jet sizes, i just bought a kit from poland that had smaller jets than the ones fitted so i kep the original and replace only the gaskets.

By the way one doubt... the starter has 2 cables only that both attachs to the same place? It gets ground from the gearbox/block connection to the chassis? Is that?

Thanks
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on February 14, 2011, 06:25:35 PM
I had to have a think about the direction of the louvres myself & came to the conclusion that there will either be a + or - air pressure under the back of the car when it is in motion so either way there will be air movement into the engine bay.
As for the main & air jets on the 28 IMB they seem to have gone through a bit of a roller coaster ride in terms of size throughout the range & as you say the later Polish carbs had the smallest jet sizes of all. As I found out biggest is not always best and the key thing is the balance between the main jet that will meter the fuel and the air jet that will control the mixture. One of my pet projects at the moment if you look in the 500 section on the forum.
The main black battery lead goes on the starter motor connection along with the thick brown wire that runs up to the control box. As you say the starter motor earths out on the engine etc  [-/
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 14, 2011, 06:38:08 PM
well it seems that i have everything well connected.
I just need today to put the fuel pipe from the pump to the carb and the car is ready.
I'm a bit of afraid to test it lol.
The engine had worked before out of the car but i'm afraid that i have done something wrong putting it in place  :oops:

i guess the starter is too close from the pipe that take the air from the engine to inside the car.
Probably because the gearbox is from a 126 and the car is a 500?
Title: Re: heat shields on a tuned engine?
Post by: 1973/126 on February 14, 2011, 06:52:11 PM
 I think you are right about that heater channel. I had to replace it for a 126 one when I done the same on my 500.
 Have you got a pull leaver starter, or the later type?
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 14, 2011, 06:55:55 PM
it's a pull lever starter.

by the way.. the anti backfire thing it's supposed to be installed inside the pipe that goes from the valve cover to the air cover???

it's suposed to have fire in that area?
Title: Re: heat shields on a tunned engine?
Post by: Allan on February 14, 2011, 07:27:45 PM
Flash supressor. My SLR had one on it in my Army days.
In reality it has two effects. One is to stop any problems caused by a backfire and the other is to stop the oil mist from clogging up the air filter. They need cleaning on a regular basis too.
Allan
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on February 14, 2011, 08:10:08 PM
Good luck with the start up  [-/
As for the "backfire" thing , I think that component is wrongly described and it is more of a fairly crude scrubber ( don't get excited boys! ) that is there to catch oil mist & droplets and return the oil back into the system hence the angle on the outlet of the standard rocker box cover.
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 15, 2011, 10:01:16 AM
the backfire should be place in the end near the air filter or in the end near the valve cover? or in the middle of the pipe?

also the connection from the carb to the air filter.. originally it has a metal pipe between this 2 parts, theres anything wrong in use only one rubber pipe from one side to the other? (like in this picture)

(http://img651.imageshack.us/img651/8370/54477952569c6caf1b18z.jpg) (http://img651.imageshack.us/i/54477952569c6caf1b18z.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on February 15, 2011, 06:06:13 PM
That rubber hose should be OK for a start up but I would keep an eye on it when the engine is hot as it may soften & colapse inwards on high revs. I am running with the 126 594 ccs metal tube & rubber connectors. I have been looking in all my books today about that backfire thing. Not enough time now to tell the whole story but you will be OK putting it where it best suits you  [-/
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 15, 2011, 08:11:32 PM
Can you help me with the earth strap? Where under the dínamo i have to connect? http://img20.imageshack.us/i/imagesjl.jpg/
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on February 15, 2011, 09:18:43 PM
That nearest M8 bolt at the base of the ally dynamo mounting casting is easiest.  [-/
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 15, 2011, 10:18:17 PM
ah ok
i thought it had to be really bolted to the dinamo directly

now it's clear :)

Thanks
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 17, 2011, 10:20:35 PM
the car is running :D
runs well but as everything is new it still smokes a lot.
Anyone can tell me how to tune the carb? it's a weber 28 as i said before.

Thanks
Title: Re: heat shields on a tunned engine?
Post by: DEYAN IYI on February 17, 2011, 11:27:45 PM
 :D Congratulations!!!  **-

You need a fuel air meter (in a car service for example). If you can't reach the correct mixture, you'll have to play with the jets. No other way to do it "by book" with the new camshaft and exhaust :D
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 19, 2011, 11:03:57 PM
hello
while putting the engine in one piece again i found some parts that i didn't used because i forgot where they were  :oops:
One of them is this ones: http://cgi.ebay.de/FIAT-500-126-ACCELERATOR-THROTTLE-CABLE-LINKAGE-CLIP-/200461215750?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2eac6b6806

Anyone can show me where to use it? Thanks
Title: Re: heat shields on a tunned engine?
Post by: GTMaster on February 19, 2011, 11:16:15 PM
You'll definitely need those if you don't want the throttle linkage to fall apart :)

There's a rod that has both ends bent which goes from the throttle cable linkage (near the air filter housing) to the end of the throttle plate rod lever on the side of the carb that faces you.
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 19, 2011, 11:19:15 PM
weird i had it togehter with the bolt from the clutch cable.

anyway.. do you have a picture or scheme of the car with this so i can understand better please?
Title: Re: heat shields on a tunned engine?
Post by: GTMaster on February 19, 2011, 11:22:27 PM
(Used your picture Rusty  :P)
Circled in red is where the clips go


Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 19, 2011, 11:25:50 PM
hum that one i have.

maybe it's another part. i have to take a picture so you can help. theres any thing similar to this near the cluth cable?
Title: Re: heat shields on a tunned engine?
Post by: GTMaster on February 19, 2011, 11:32:29 PM
The cables that run under the car are the handbrake cables, speedo cable (at back of gearbox near the tunnel), clutch cable, starter cable (if it's the old type of starter motor) while the throttle cable and choke cable are led up into the engine bay....
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 19, 2011, 11:38:57 PM
it's this.
just found
Title: Re: heat shields on a tunned engine?
Post by: GTMaster on February 19, 2011, 11:41:53 PM
That holds the clutch cable in place on the side of the gearbox (left hand side above rubber gearbox mount), with a spring washer and M6 nut if i remember correctly (could be an M6 bolt)... the bottom of that bracket goes into a slit on the gearbox...
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on February 20, 2011, 08:21:54 AM
Some clutch cables have the gearbox mounting bracket fixed to them & others use a separate bracket  [-/
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 20, 2011, 06:55:27 PM
today i have drove about 3km with the car.
the smoke is now less than before but i guess something is wrong in the air cowling.
I ear a lot of noises from that area. Can be the fan touching the cowling? If so can i remove remove only the top hat of the cowling and the front and keep the rear? Sounds a good idea? I cant see nothing from the top so i believe that i have to remove everything and check if everything is good inside, right? Anyone can help me with this and give me some tips? Thanks
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on February 20, 2011, 08:16:43 PM
If you run the engine & the fan goes bust then it could be a disaster. Suggest you remove fan belt and start the engine to see if the noise stops but do not run the engine for too long  [-/
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 20, 2011, 09:13:54 PM
yeah i'll try that tomorrow as i'm not sure if the noise is the normal noise of the engine.
i remeber the car with the original engine was very noisy, so as this one is tunned i'm not sure if it's normal or now. the fan should make absolutly no noise at all? thanks
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 22, 2011, 03:20:11 PM
problem solved i guess.

sounds good? (the choke is pulled)

http://www.youtube.com/watch?v=6e8Q9lNPbPM
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 23, 2011, 05:19:07 PM
:D Congratulations!!!  **-

You need a fuel air meter (in a car service for example). If you can't reach the correct mixture, you'll have to play with the jets. No other way to do it "by book" with the new camshaft and exhaust :D

which jets i should use with this combinations?

650cc, 35/75 camshaft, -2mm head, 28/35,7 valves, 4kg flywheel, record monza replica exhaust.

It's a weber 28imb

Thanks
Title: Re: heat shields on a tunned engine?
Post by: DEYAN IYI on February 23, 2011, 08:24:09 PM
Have no idea, man. The a/f meter till tell you what is good to use, but for this you need some different close sized jets. I really don't know if you can buy a set from Italy or Poland.

Find and read something about carb adjustment. It's a funny thing. Soon I'll have to tune my Dellorto DHLA 40, so I'm in the same rebus, but for this type of carbs there are all possible jet sizes, anyway I still don't believe that it will be a peace of cake... :)

Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 27, 2011, 07:25:40 PM
It seams i have a problem...

(http://img42.imageshack.us/img42/2483/5482075615d8c655dc2eb.jpg)
(http://img218.imageshack.us/img218/8966/54820766418ca8f7ea1bb.jpg)
(http://img714.imageshack.us/img714/9229/5482674152be41b4db34b.jpg)


:(

Everything is new... why this happends?
Title: Re: heat shields on a tuned engine?
Post by: 1973/126 on February 27, 2011, 07:53:30 PM
 It looks from the photo that one of your push rod tube seals is not in place properly. This would explain the oil leak.
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 27, 2011, 08:47:17 PM
yeah i saw that too.. the engine has 1 week and i did about 30km with the car. i saw the engine assembly. i know that the seal were put in place properly. it's posible that it left his place with the engine pressure or something like that? a poor quality seal or even a poor quality push rod tube?
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 28, 2011, 12:27:13 AM
Its possible to remove the cowling house keeping the exhaust and distribuitor?
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on February 28, 2011, 09:27:33 AM
I think that you are going to have to remove the cylinder head to sort that out properly. I would doubt that that seal would blow out due to crankcase pressure. Excessive pressure would blow up those tubes and exit via the rocker cover breather. Those tubes and seals are a bit tricky when you refit the head. I tend to lightly oil the seals on assembly and as you lower the head on the studs make sure the tubes locate correctly and that they will turn fairly freely until you start to tighten the head down. Then check that they are locked in place after final tightening. The tubes have bellows like sections that can take a bit of spring but if a tube is not located properly on assembly then it can get squashed and shortened. Also those seals are available different thicknesses , good luck  [-/
Title: Re: heat shields on a tunned engine?
Post by: alapimba on February 28, 2011, 09:44:36 AM
i have the head lowered about 2 or 3mm not sure. and i used standard seals. can be that the reason? too much pressure? on the seals?

or should i have used other kind of tubes?

to fix it i have to remove the distribuitor, cowlings, remove head, remove tubes, replace seals and bolt everything again, right?

Title: Re: heat shields on a tuned engine?
Post by: 1973/126 on February 28, 2011, 10:14:56 AM
 Your lowered head could be one of the reasons, or just what Rusty said before.
 On one of my engines where the head is lowered a lot, I actually have shorter push rods and tubes and some alloy shims under the rocker arm.
 You only need to take the distributor cap of to take the thermostat housing off.
Title: Re: heat shields on a tunned engine?
Post by: Darrell on February 28, 2011, 09:37:52 PM
I removed the tin thermostat housing and saw that the leak I had was coming from the rocker cover, so could be the seals are ok.
Title: Re: heat shields on a tunned engine?
Post by: alapimba on April 04, 2011, 03:04:13 PM
hello

my tubes are the ones without harmonica. which seals i should use? thin or thick?
or should i just dump this tubes and use the oens with harmonica? if i need to go with harmonica i should use standard ones or the tunning ones with spring on the middle?

Thanks
Title: Re: heat shields on a tunned engine?
Post by: smallcox on April 06, 2011, 08:21:39 PM
Hi,

Well we have all been there, just finished our newly painted engine and looks good with shinny bits then almost straight away oil everywhere and now you feel :cry:

Just read what you done and well shorter push-rod tubes are going to be the solution. we have all skimmed heads and 1-2mm you may just get away with it but if only 1 tube is leaking you may be alraight with a new seal on it. As for those springeeeeee push rod tubes, all there fit for is blowing your trumpet through them :)

check the tube that is leaking to see if the tube is damaged, if not try a new seal, if you have removed more than 1.5-2ish from the head then you can shortern the original tubes and the weld them back together as a solid fix ;D

I see you had load off tuning bits put on the engine, I quess you would be excited about getting it sorted for road use, as for tuning the carb only one way to sort the calibration off that carb "ROLLING ROAD" find a tunner that good with webbers and 1 hour he should dial that buti in

Nice job by the way
Title: Re: heat shields on a tunned engine?
Post by: alapimba on June 02, 2011, 03:06:36 PM
hi

after a few months today i took the engine off because it had the oil leak but also a exhaust leak.
the leak was on the manifold but also on the head.... i found that the cylinder head gasket exploded on one side.

now my doubts...
- i have the head too short and it has too much compressiond and the gasket didn't resist?
- the tubes were not the correct ones for this head because were shorter and didn't allowed the head to be tight properly and make this cylinder head gasket exploded?
- which tubes i should use?
(http://www.fiat500ricambi.nl/beheer/fotos2/MO1150_normaal.jpg) or (http://www.fiat500ricambi.nl/beheer/fotos2/MO1049_normaal.jpg) ?

Thanks
Title: Re: heat shields on a tunned engine?
Post by: Darrell on June 03, 2011, 10:29:49 AM
I think the ones on the right are better although I have never met anyone who has used the ones on the left.

I guess how good they are depends on the strength of the spring and how good the spring is at being in the heat.
Title: Re: heat shields on a tunned engine?
Post by: smallcox on June 03, 2011, 02:04:52 PM
Hi,

My friend had the ones on the right, with the springs fitted to beetle engine and they leaked oil all the time. The one on the right looks a better bet BUT what lenght is it because some performance mods require longer tubes and they can only be crushed so much, then you got the problem you started with.

Best thing I would do is shortern your originall one by the same amount that was rewmoved by the cyclinder head.

As they are steal cut the tube about an inch up from one end then remove X amount and have a welder person put them back together again, it's going to be the cheapest option I would imaging, and then you can use original seals on them and they will be strong. ;)
Title: Re: heat shields on a tunned engine?
Post by: alapimba on June 03, 2011, 02:50:09 PM
sorry but i got confused.
you mentioned the ones on the right twice eheh.
Title: Re: heat shields on a tunned engine?
Post by: DEYAN IYI on June 04, 2011, 11:29:59 AM
This kind should be the best possible. There are on the net 500/126 projects with Bug's push rod tubes. It seems that they fit straight.

 ;) 40sec.& 2min.16sec.http://www.youtube.com/watch?v=jWS-sg8ML6w&feature=related

(http://images2.carpartsdiscount.com/auto/archive/pictures/122556/600/1/P/2C48853/vw_beetle_1967_push_rod_tube_oem_rp_108_rp108.jpg)

http://www.carpartsdiscount.com/auto/parts/67/volkswagen/beetle/push_rods/push_rod_tube.html?3593=122556
Title: Re: heat shields on a tunned engine?
Post by: alapimba on June 04, 2011, 12:08:19 PM
humm indeed this seems a good option, do you have more examples of cars using this tubes?

thanks
Title: Re: heat shields on a tunned engine?
Post by: alapimba on June 04, 2011, 12:12:16 PM
(http://img220.imageshack.us/img220/7247/imagem002nr.jpg)



the head gasket of my engine...this was the result
Title: Re: heat shields on a tunned engine?
Post by: smallcox on June 04, 2011, 08:32:06 PM
sorry about that, don't know my right to my right :$

As for that had gasket, looks ok to me :-
Title: Re: heat shields on a tunned engine?
Post by: alapimba on August 21, 2011, 11:03:26 PM
a little update.
the tubes were replaced with the expensive ones.
the person that put the engine in one piece said that it probably were with a really high compression due to the 2mm skimming so we used the 1.8mm head gasket.

This week i did a travel of 320km on highway on monday and today i did the 320km back and the engine seems to run well.

100/110km/h, top was about 115km but the car was not very stable so i didn't tried more, i believe it will reach the 120km/h with this setup.

The only bad thing was a tire that exploded
(http://img268.imageshack.us/img268/1580/31843810150252936381362.jpg)
 :o

I'm gonna replace now the 4 tires and later i'll probably replace the 28imb weber, just don't know with what.

anyway.. at the moment my problem seems to still be with the fan. on the back the fan bolts to the dinamo with only a cone shaped washer and a self locking nut? nothing else? no washers no nothing?

Regards

Title: Re: heat shields on a tunned engine?
Post by: DEYAN IYI on August 22, 2011, 03:27:46 PM
Nice burn out ;D :$ If you want, look for 145/70 R12 - they appear better, but also more stability (on theory) - it's 1cm lower and wider. Maybe the best size over original rim 4J12 (but yours are 3,5J12...!? So... Well, sorry about this blah-blah of mine ??? wanted to be helpful). :-X

About the fan, there are tin and plastic washer on both sides, the plastic ones are inside. A friend of mine had problems with the fan, those were missing- he took it like this from Poland (went there by bus just to buy a 126, cos his old one became real crap). Then the fan turned around the base...  :( A friend of ours "cleverly" welded them together (no comment). But of course the bearing died (it was a new one). Then he bought a brand new fan and I took care to put all together. You can see the handmade washers shaped after my original once. The tin is 0,7mm and the plastic (not a hard one) the most suitable you can find in the garage. Well, it was perfect till the next alternator problem. I wasn't around, so that guy "helped" again. For some reason he couldn't put them together, removed the washers on one side, said "you don't need this!" and as a result not that late, he had to weld the brand new fan just like the old one. Now I wanna kill him, but he's a nice guy to drink beer with. ;D If you can imagine, he earns his bread as a car mechanic..., poor cars ??? And there are more "funny" stories... ::)

Regards! :)
 
Title: Re: heat shields on a tunned engine?
Post by: GTMaster on August 22, 2011, 06:40:00 PM
 :o That's the end of that tyre (was it very worn or did it overheat from the high speed?)
On my fan i used a spring washer and a self locking nut with a touch of thread locker glue and tightened it down. Hopefully that won't loosen.... It is important to use all the bits that are there originally (washers etc).
Title: Re: heat shields on a tunned engine?
Post by: alapimba on August 26, 2011, 10:39:45 PM
the tyre was very worn... my bad to use the car in that conditions, thank god nothing bad happend.

damn washers... to put the inner washer i have basicly to remove the engine to then remove the cowling and fan and put the washer and put everything in place again, right? :(
Title: Re: heat shields on a tunned engine?
Post by: GTMaster on August 28, 2011, 10:23:05 AM
I was able to take the cowling off without removing the engine. The big hose at the back has to be taken out and the top cover (air filter) has to be removed as well. You should be able to get to all the bolts that hold the cowling onto the engine block (they're all within reach from under the car as well...)
Title: Re: heat shields on a tunned engine?
Post by: alapimba on October 25, 2011, 10:28:13 AM
ops i did it again...
what the f*ck can be wrong in my engine?
is this head that it's already so bad that don't have any solution?

(http://img402.imageshack.us/img402/8563/fotografia1k.jpg)
(http://img37.imageshack.us/img37/5483/fotografia2g.jpg)
(http://img809.imageshack.us/img809/5950/fotografia3l.jpg)
(http://img822.imageshack.us/img822/8900/fotografia4m.jpg)
(http://img696.imageshack.us/img696/418/fotografia5t.jpg)
Title: Re: heat shields on a tunned engine?
Post by: nrg19uk on October 25, 2011, 12:24:14 PM
Did you have the head skimmed last time?
Title: Re: heat shields on a tunned engine?
Post by: DEYAN IYI on October 25, 2011, 01:03:48 PM
Disgusting view  :- Sounds like overheating  :$

It's interesting what is the compression ratio. You say that's 2 or 3mm lowered...  Swiatek #385 (288*, yours is 290* so the same) camshaft requires 1.8-2.5mm lowered head. Measured by me -1.8mm (old type combustion chamber, not 650E or Panda 30) with standard gasket 1.1mm (if I remember well) gives 9.4:1 CR. In my opinion -2.5mm will be about 10.5:1, and maybe is a bit too much for everyday use. (Abarth 595 has 10:1 and the "berlina" type 695 8.5:1; 695SS 10.5:1).

Check the volume of yours like this.

(http://img717.imageshack.us/img717/9915/deyanpix1256.jpg)

What gasoline do you use? This setup needs 98 or 100.

Spark plugs? You will probably need (if you run standard ones) colder heat range: NGK 8, Champion 6, Bosch 4, Denso 24. The most suitable number you will find out testing it, but start from colder to hotter! Also take modern plugs.

The static ignition advance according to Swiatek must be about 15*. For 126 there are the old type of distributor 18* +/-2* over 3000rpm and the new type 21* +/-2* over 3900rpm and both 10* static advance. For Abarth is 4* static and 34* automatic, but maybe with special type of distributor. Anyway it comes to about 35* final advance.

Do not over tight the head! If it's more than needed, when overheats, aluminum expands and smashes the gasket.

And not on last place, make sure that it is not running on bad mixture! Lean causes overheating.

If you need a new head, look for a 650E one! To be 9.4:1 needs -1.4mm lowering.

Polish the chamber to prevent carbon deposit and the bad effects that gives.

Make sure that the contact surface is flat!

I hope it was helpful ;)

Have fun! :)
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on October 25, 2011, 02:52:25 PM
Ouch , that looks messy again. One thing is for sure , you are going to have to use a solid copper head gasket next time. If you can find the right people you should be able to have the head repaired by specialist welding but I am guessing that you do not want to increase the compression ratio any more so minimum of skimming. You are not alone with engine disasters as my "special" engine only ran for 100 miles or so before I hit problems but that was due to hidden sandblast grit in the rocker box cover which has ruined the engine. But when I put it together I upped the torque on the cylinder head nuts a little knowing that I was running a higher compression head, good luck  :)
Title: Re: heat shields on a tunned engine?
Post by: smallcox on October 25, 2011, 03:19:57 PM
That's not to good,

As for your compression ratio, I do not beleive this to be the problem as from the pictures I run a simular head with a standard cam no problem and looking at how much is removed from the picture on standard pistons would be about 8.8:1. there is an underlying problem but you could get the head skimmed a bit to remove the damage from the face and then insert a couple off copper rings under the barrels to lift the cyclinders up. This is not good practise but would be this cheapest option. Is the exhust blocked because you shoud not have that amount off heat build up locally in the exhaust port
Title: Re: heat shields on a tunned engine?
Post by: alapimba on October 25, 2011, 03:23:36 PM
Did you have the head skimmed last time?

just the enought to have it flat again when the gasket reached the head
Title: Re: heat shields on a tunned engine?
Post by: alapimba on October 25, 2011, 03:33:25 PM
Disgusting view  :- Sounds like overheating  :$

It's interesting what is the compression ratio. You say that's 2 or 3mm lowered...  Swiatek #385 (288*, yours is 290* so the same) camshaft requires 1.8-2.5mm lowered head. Measured by me -1.8mm (old type combustion chamber, not 650E or Panda 30) with standard gasket 1.1mm (if I remember well) gives 9.4:1 CR. In my opinion -2.5mm will be about 10.5:1, and maybe is a bit too much for everyday use. (Abarth 595 has 10:1 and the "berlina" type 695 8.5:1; 695SS 10.5:1).

Check the volume of yours like this.

(http://img717.imageshack.us/img717/9915/deyanpix1256.jpg)

What gasoline do you use? This setup needs 98 or 100.

Spark plugs? You will probably need (if you run standard ones) colder heat range: NGK 8, Champion 6, Bosch 4, Denso 24. The most suitable number you will find out testing it, but start from colder to hotter! Also take modern plugs.

The static ignition advance according to Swiatek must be about 15*. For 126 there are the old type of distributor 18* +/-2* over 3000rpm and the new type 21* +/-2* over 3900rpm and both 10* static advance. For Abarth is 4* static and 34* automatic, but maybe with special type of distributor. Anyway it comes to about 35* final advance.

Do not over tight the head! If it's more than needed, when overheats, aluminum expands and smashes the gasket.

And not on last place, make sure that it is not running on bad mixture! Lean causes overheating.

If you need a new head, look for a 650E one! To be 9.4:1 needs -1.4mm lowering.

Polish the chamber to prevent carbon deposit and the bad effects that gives.

Make sure that the contact surface is flat!

I hope it was helpful ;)

Have fun! :)

Hello

THank you a lot for your post.

Regarding the CR, we measured it because since the last blown gasket i always thought about that issue so acording to my counts, using the gasket that i used of 1.8mm the CR was at less then 9,5:1 i guess it was 9,1 if i remember correctly. My mechanic measured as you show in your picture.

I did about 1600km this time until this happend and around 600 was on the highway, 300km one day and 300 in other with only stoping one time and driving at around 100km/h.

I allways use 98 fuel with adictive.

You mentioned overheating and bad mixture and indeed my car was running too rich. [youtube]http://www.youtube.com/watch?v=jOIQrdgL0lc[/youtube]...

Do you think this was the cause? in the day that the problem occured i was driving slowly, the day was a hot but not too much.

One doubt that i have now is.. this head will still be of good used? if i go with a cooper gasket this time it will have i guess 1,2 or 1mm it means it will be a stronger gasket but even more compression due to the lower combustion chamber, right?

What should i do? i really didn't wanted to put a std head and loose power (the car was really nice before the problems) but i'm really sick of problems...

I saw that 650E heads on ebay.. should i go with this route?

Regards
Title: Re: heat shields on a tunned engine?
Post by: alapimba on October 25, 2011, 03:42:25 PM
That's not to good,

As for your compression ratio, I do not beleive this to be the problem as from the pictures I run a simular head with a standard cam no problem and looking at how much is removed from the picture on standard pistons would be about 8.8:1. there is an underlying problem but you could get the head skimmed a bit to remove the damage from the face and then insert a couple off copper rings under the barrels to lift the cyclinders up. This is not good practise but would be this cheapest option. Is the exhust blocked because you shoud not have that amount off heat build up locally in the exhaust port

the last time i already did that and used 2 copper rings on each barrel to try to don't have such a high compression...

the question with the head at the moment according to my mechanic is... the reason from the problem can't be the weakness on the head? as you see on the picture it bends easily due to be so skim and can cause the head to lift or the gasket or something like that and allow it to lift and then the gasket blow?

Title: Re: heat shields on a tunned engine?
Post by: smallcox on October 26, 2011, 05:16:25 PM

((((Do you think this was the cause? in the day that the problem occured i was driving slowly, the day was a hot but not too much.))))
If you get bad backfire when engine is switched off from idle this is a glue off a weak mixture, Thi sin it's self destoyes engines.
The original head gasket is more than capable off handling the extra power


Title: Re: heat shields on a tunned engine?
Post by: alapimba on October 26, 2011, 05:28:31 PM
Whats your opinion about my cylinder head? should skim it and try to use it one more time or this was his dead?

Regards

Title: Re: heat shields on a tunned engine?
Post by: smallcox on October 26, 2011, 05:48:38 PM
Without seeing the cylinder head first hand makes that a hard one, but if you can get it skimmed and cleaned up then I don’t see any reason why not. The compression can be altered by removing material from the combustion camber or/and fitting a spacer under the cylinders to get the desired c/r. don’t get over fixed on the c/r as this I don’t believe to be you main problem. With a longer duration cam you can run higher c/r’s.
Use a good quality original gasket not the cooper type as the copper type will cause more damaged should something go wrong.

Once completed gat the engine check the fuel/air ratio as a rich mixture will not cause the damage you show but a weak mixture will. Also at idle feul ratio will be different than when at engine speed. did you have the carb rejetted after the mods again if not this will defently cause a weak mixture.

Good luck
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on October 26, 2011, 06:11:47 PM
 :D smallonegurubloke you are the Man,  ;D
You may have just solved my problem as well. When I put the tuned head on my 499ccs and the other bits all was well but I got that backfire when you turn off the engine.
My shortlived 652ccs engine with all the goodies would also backfire. I am running an oversize carb on the 499 and tried standard on the 652 to see how things went and I am a bit of a hammer chewer in this tuning department  :P
So I reckon that a little bit of "messin' with the jettin' " is in order  :)
Title: Re: heat shields on a tunned engine?
Post by: alapimba on October 28, 2011, 04:28:05 PM
Hello

I have been inspecting this head and comparing with a friend cylinder head that has a race engine with 10,2:1 compression and we realised that my head were probably run with a even bigger compression ratio so it's better forget about it.
Now i have to start again from 0, so i'll buy a new head.

I'm thinking in a 650 "E" head and use the valves from the old head.
What do you guys think? for this i'll spend around 250€ i guess in the new head, shipping and machine it to fit the bigger valves.

With this budget i should go with another route?
THanks
Title: Re: heat shields on a tunned engine?
Post by: thepuddlejumper on October 28, 2011, 10:29:52 PM
Empi push rod tubes see, only problem you need to buy 4.

Ralph

http://www.vwheritage.com/vw_spares_Pushrod-tubes-adjustable-set8_act_shop.product_pID_100279_lang_EN_country_GB.htm
Title: Re: heat shields on a tunned engine?
Post by: alapimba on October 28, 2011, 11:38:32 PM
Empi push rod tubes see, only problem you need to buy 4.

Ralph

http://www.vwheritage.com/vw_spares_Pushrod-tubes-adjustable-set8_act_shop.product_pID_100279_lang_EN_country_GB.htm

O have it already fixed. The problem now is other
Title: Re: heat shields on a tunned engine?
Post by: alapimba on November 09, 2011, 12:33:24 PM
Got my new head today.
now i have one doubt... what is the job of this holes in the head?
Should i bolt something here? i didn't had this on the other head... or at least were filled

(http://img585.imageshack.us/img585/6826/fotografia2a.jpg) (http://imageshack.us/photo/my-images/585/fotografia2a.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
Title: Re: heat shields on a tunned engine?
Post by: Rusty's Uncle on November 09, 2011, 01:31:33 PM
That looks nice and shiney  :D
The groove and the hole are a safety feature so that if the head gasket blows the exhaust gases go into the groove , up the hole then out through a special hollow bolt that goes through the tinware then into the head in that M10 threaded hole shown in the picture. Without that feature if the head gasket goes and you have the heater on then you will be pumping carbon monoxide into the cabin  :o
Some people have over skimmed the head and that groove has disappeared. Also if you go for a big bore kit as the diameter of the piston gets so close to the groove then that groove has to be filled. I did post a picture of the head from my 795ccs where the groove had been welded up some time ago.
Title: Re: heat shields on a tunned engine?
Post by: alapimba on November 09, 2011, 02:08:07 PM
Hum i see
But what for is the bolt if it has a hole?
Can't i just leave this whitout bolt?
Title: Re: heat shields on a tunned engine?
Post by: thepuddlejumper on November 09, 2011, 07:08:08 PM
The holes and groove are to allow gasses to exit if the head gasket blows, this keeps the cab free from the fumes.  There is a special bolt which srews into the hole.

Ralph
Title: Re: heat shields on a tunned engine?
Post by: DEYAN IYI on November 11, 2011, 09:36:20 PM


(http://www.126fan.sk/eshop/images/1050707%20(7).JPG)

http://www.126fan.sk/eshop/index.php?main_page=product_info&cPath=6&products_id=548
Title: Re: heat shields on a tunned engine?
Post by: alapimba on November 11, 2011, 10:16:46 PM
O found that i had this bolts from a spare engine, i just didnt understand the reason for it exist
Title: Re: heat shields on a tunned engine?
Post by: ape20ff on November 25, 2011, 08:26:45 PM
Hello to everybody.
If somebody needs air/fuel guage for tuning carbs here you are:
http://74.54.120.132/dbbp/tech-tips/mm.html
That's not a problem,the web is full of projects like that.
http://www.jaycar.co.uk/productView.asp?ID=KC5195&form=CAT2&SUBCATID=965#11
http://autospeed.com.au/cms/article.html?&A=0217
http://autospeed.com/cms/title_InCar-AirFuel-Ratio-Gauge-Buyers-Guide-Part-One/A_3032/article.html
Once upon a time I saved some pictures from the hungarian site of lada.
(http://s11.postimage.org/fu15sas27/image.jpg) (http://postimage.org/image/fu15sas27/)
(http://s8.postimage.org/dxxdkc6ht/image.jpg) (http://postimage.org/image/dxxdkc6ht/)
(http://s12.postimage.org/btet16655/image.jpg) (http://postimage.org/image/btet16655/)
(http://s7.postimage.org/k9gynzp5j/image.jpg) (http://postimage.org/image/k9gynzp5j/)
(http://s12.postimage.org/whdgfwrdl/image.jpg) (http://postimage.org/image/whdgfwrdl/)
(http://s8.postimage.org/xjv180noh/image.jpg) (http://postimage.org/image/xjv180noh/)
(http://s8.postimage.org/fou6r1s69/image.jpg) (http://postimage.org/image/fou6r1s69/)
(http://s9.postimage.org/f8ldnptrf/image.jpg) (http://postimage.org/image/f8ldnptrf/)
(http://s10.postimage.org/ye9q14139/image.jpg) (http://postimage.org/image/ye9q14139/)
(http://s7.postimage.org/wbgxvvnrr/p10.jpg) (http://postimage.org/image/wbgxvvnrr/)
(http://s12.postimage.org/telx40r6h/p11.jpg) (http://postimage.org/image/telx40r6h/)
There are 20 leded gauges with 2 integrated circuits for a more accurate reading,I have to look for them.
I can't adjust or repair a carb,of course it takes to swap jets for tuned engine.
The standard main jet for a 28 carb is 115,maybe that engine need a 120-125 one.
Standard 650 and 650E engines have diffrent jets but the main. Generally they use the same as the standard carb for light tuned engines so if you have a non 650E carb meybe the swapping of the main jet only can be enouh.
Bye.
Title: Re: heat shields on a tunned engine?
Post by: Emin on November 25, 2011, 09:02:34 PM
Thanks for that which combines my two hobbies. I guess it takes time to find the right place to put the lamba sensor. The other point is to find a working lambda sensor from junkyard for free. Saved for future.
Title: Re: heat shields on a tunned engine?
Post by: ape20ff on November 30, 2011, 10:29:28 PM
Hello.
That's the 20 led one.
http://www.siipicossu.com/seosmittari.htm
I don't think you have a muffler like this:
(http://s10.postimage.org/tjvp14hqt/lambda_big.jpg) (http://postimage.org/image/tjvp14hqt/)
So you have to think of a place on the muffler.
You need a simple lambda,mind that thelife of a lambda sensor is about 60000km.
Bye.