cylinder head choice
cylinder head choice
Can anyone tell me if there is any reason to replace the cylinder head on my 79 2L engine, carb with a 2L FI head. Also is the FI exhaust manifold a better performance manifold than the 79's 4-2-1? Lastly what is a safe amount to mill from either of these cylinder heads?
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Re: cylinder head choice
The ports are the same in those two heads, so the only reason to replace would be cosmetic.
Likely the two exhaust manifolds are about the same, but I doubt anybody has done any actual testing.
Neither head should be milled at all. If you want to increase compression deck the block instead, or use high compression pistons. Most of the time the pistons are below the deck at TDC. They can stick out by 0.5mm (.020").
If you use a 1800 head it will increase compression to ~8.6:1 (from 8.1:1).
Likely the two exhaust manifolds are about the same, but I doubt anybody has done any actual testing.
Neither head should be milled at all. If you want to increase compression deck the block instead, or use high compression pistons. Most of the time the pistons are below the deck at TDC. They can stick out by 0.5mm (.020").
If you use a 1800 head it will increase compression to ~8.6:1 (from 8.1:1).
Csaba
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
'71 124 Spider, much modified
'17 124 Abarth, silver
http://italiancarclub.com/csaba/
Co-owner of the best dang Fiat parts place in town
- bradartigue
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Re: cylinder head choice
Read your other post...also those exhaust manifolds, the 79 4-2-1 and the FI 4-2-1 are essentially the same thing, you don't need the FI one so don't bother.
1970 124 Spider
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Re: cylinder head choice
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Last edited by fiatfactory on Tue Jul 02, 2019 5:13 am, edited 1 time in total.
nothing to see here... move along.
- bradartigue
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Re: cylinder head choice
I'm inclined to agree - you keep asking the same thing - get it into your head that the design of these engines was to increase compression through pistons changes, not head work. FIAT sold HC pistons through dealerships for those who wanted to do this, it was just how it was done. And plenty of piston options exist even today.
1970 124 Spider
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Re: cylinder head choice
The FI heads don't have air injection ports (cleaner) and don't have the EGR feedback path through the front of the head. Hence, you don't have as much to plug up or block on the installation. My 1980 already had that conversion done which meant NONE of the EGR/emissions stuff did anything and was "un-needed". I've got a 79 Lancia Beta head that is practically new that I'm itching to build with higher HP cams.
SoCal: I'd love to talk by phone with you about cams and heads and stuff sometime....
Soup
SoCal: I'd love to talk by phone with you about cams and heads and stuff sometime....
Soup
Re: cylinder head choice
Ok... I get it!!! I'll keep looking in my stash of stuff for my 1800 head, or buy one from this site If I see one for sale. I'm not against the piston swap, it's just that it is running fine. But It's quite slower than the 73 I had back in the day..sigh, So for now it's going to be a single plane manifold & 34ADF
- bradartigue
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Re: cylinder head choice
The new manifold and carb will bring it back to life. The 79 had 81 HP. The 73 had nearly 100 HP. The 79 with an 1800 manifold and 34ADF will have more than 100HP - more torque than a 73 as well.buckspet wrote:Ok... I get it!!! I'll keep looking in my stash of stuff for my 1800 head, or buy one from this site If I see one for sale. I'm not against the piston swap, it's just that it is running fine. But It's quite slower than the 73 I had back in the day..sigh, So for now it's going to be a single plane manifold & 34ADF
1970 124 Spider
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Re: cylinder head choice
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Last edited by fiatfactory on Tue Jul 02, 2019 1:19 am, edited 1 time in total.
nothing to see here... move along.
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Re: cylinder head choice
I think I read a while ago the 16v Lancia Integrale head will fit. Anyone know if that is true?
Don Avery
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
Dayton, OH/Sarasota,FL
1985 Pininfarina
2011 Eos
2012 Mercedes E550 Cabriolet
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Re: cylinder head choice
Yes they fit. But it's a lot more work than just bolting it up. Sourcing a good one with cams will be your first of many hurdles.davery wrote:I think I read a while ago the 16v Lancia Integrale head will fit. Anyone know if that is true?
Mick.
'82 2litre 131, rally cams, IDFs & headers.
'82 2litre 131, rally cams, IDFs & headers.