82' 2L cylinder head chamber development

Keep it on topic, it will make it easier to find what you need.
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surfingfreeman
Posts: 388
Joined: Sat Jan 16, 2010 10:34 pm
Your car is a: 1982 2000 FI
Location: Burlingame, California

82' 2L cylinder head chamber development

Post by surfingfreeman »

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Image
Hello All
Wondering which of the 2 images has the more "ideally developed" chamber for a engine rebuild including bigger valves and mark's snake header. In your reply if you could describe what about the differences makes if a more suitable chamber. Thanks
Mike
surfingfreeman
Posts: 388
Joined: Sat Jan 16, 2010 10:34 pm
Your car is a: 1982 2000 FI
Location: Burlingame, California

Re: 82' 2L cylinder head chamber development

Post by surfingfreeman »

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hope this sizing is better.
surfingfreeman
Posts: 388
Joined: Sat Jan 16, 2010 10:34 pm
Your car is a: 1982 2000 FI
Location: Burlingame, California

Re: 82' 2L cylinder head chamber development

Post by surfingfreeman »

Image
hoping 3's a charm!
surfingfreeman
Posts: 388
Joined: Sat Jan 16, 2010 10:34 pm
Your car is a: 1982 2000 FI
Location: Burlingame, California

Re: 82' 2L cylinder head chamber development

Post by surfingfreeman »

Image
do i hear a 4th time?
surfingfreeman
Posts: 388
Joined: Sat Jan 16, 2010 10:34 pm
Your car is a: 1982 2000 FI
Location: Burlingame, California

Re: 82' 2L cylinder head chamber development

Post by surfingfreeman »

one of my concerns is that in the image of the chamber that is more fully developed there will be a resulting loss of compression, but perhaps a better atomized distribution of fuel and hence a more uniform flame front during ignition and greater downward force on the piston? Engineers and physicists please chime in!
So Cal Mark

Re: 82' 2L cylinder head chamber development

Post by So Cal Mark »

what does the top of the piston look like?
surfingfreeman
Posts: 388
Joined: Sat Jan 16, 2010 10:34 pm
Your car is a: 1982 2000 FI
Location: Burlingame, California

Re: 82' 2L cylinder head chamber development

Post by surfingfreeman »

Image
4.5mm dome piston
So Cal Mark

Re: 82' 2L cylinder head chamber development

Post by So Cal Mark »

I have serious concerns about your wrist pin retaining rings. We recently saw a failure from a VAS piston using that style of retaining ring. It allowed the pin to come out and destroy the cylinder wall. Guy Croft's opinion is that style of retainer cannot be used and will fail if the pins have any chamfer at all
TX82FIAT
Posts: 1814
Joined: Mon May 03, 2010 11:04 am
Your car is a: 82 Fiat Spider 2000 CSO
Location: San Antonio

Re: 82' 2L cylinder head chamber development

Post by TX82FIAT »

Mark, I'm still learning a ton about retaining rings so please stick with me for a minute. Are you saying that if the ring is anthing but at a perfectly flat mate/90 degree angle to the cylinder wall with this style of piston it is likely that the pin will come out and destroy the cylinder wall. I have this set up on my car and have had some oil loss issues and have attributed that to the rings not seating properly. Took synthetic out and put heavier 30 Wt in to seat the rings. Sorry to hijack the thread.. find tis discussion on this type of ring set up very interesting.
Buon giro a tutti! - enjoy the ride!

82 Fiat Spider 2000
03 BMW M3
07 Chevy Suburban
So Cal Mark

Re: 82' 2L cylinder head chamber development

Post by So Cal Mark »

I saw this happen to a 1608 as I mentioned and since I'd never seen it before I sent the pics to Croft for his opinion. He stated that if the pin has any chamfer to it, that type of retainer cannot be used since it will definitely fail. Croft says the pin must have a flat end and the piston must have a square groove of course
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