best make of pistons and heads; 1600cc vs 1641cc

Hi,

I will be replacing the heads and pistons on my bug; I was wondering what piston make is preferred for a 1600cc standard engine. Mahle seems to be popular any comments? Regardless of what pistons I use, I should balance them - is this correct? ( Mahle advertises having the convience of the piston in the jug so no need to compress the rings) - is this saying they are trustworthy to come balanced within reasonable spec.s?

is there a preference for heads for a 1600cc?

Is it ok to go up to 1641cc (?) and still be able to maintain good cylinder wall thickness and heat dissapation?

Bug will be used for my daily driver

Yes, obviously I'm a newbie with this part of bug info.

Thanks!!

Matt S

Reply to
Matt S
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Hi Matt,

Mahle is a good brand. My engine has them and it has been a good one so far. Aircooled.net had some German 1600cc piston & cylinder sets available a while back, and if you haven't bought yours yet I think that would be an option worth considering...

Dane

Matt S wrote:

Reply to
Dane Tyler

The forged Mahle pistons are very good. The cast version is ok for stock engines.

So far (countless engines :) ) Mahle pistons have been well in spec, no need to balance. BUT you should check the pistons anyway. It is still possible that someone screwed up with the packaging and one or two pistons were of different weight class. if they have a paint spot on them, the paint has to be same color.

And about having them ready fitted in the jugs.. that's just convenient and safe for shipping. You still should take them out and clean them (remove storage grease) and check ring gap in the cylinder without the piston.

Depends on what you are building :) For long life, stock style 044 heads would be nice.(long reachspark plug, more material in the roof, less prone to cracking) 35.5 x 32mm valve size, ports cleaned a little and compression ratio set to what you want it to be.. maybe clean the combustion chamber a little and unshroud the valves, (making sure you still keep cood CR), and make a small radius on all sharp edges to reduce detonation tendency.

3-angle valve job.

The gain from 40-something cc is questionable. Should be safe in a lightweight car and near stock engine.

Jan

Reply to
Jan Andersson

Dane, thanks for your input,

Jan, Thanks so much for taking the time to reply,

The car is just slated to get me back and forth to work, reliably....

without going to a shop am I able to clean the ports, combustion chamber?, and what is the best compression ratio?? - I guess I could spend time looking that up though, - but you may be more conventient ! : )

What is within spec regarding weight differences

and what is unshrouding the valves?

I guess I can make a small radius on all sharp edges via my dremel

No more questions - promise

Thanks again Jan

Matt S

Reply to
Matt S

You mentioned having a Dremel. That would suffice for minimum port work. Just remove any casting "flash", all the rough seams and splatter looking stuff from the intake and exhaust ports.

For a stock engine this is enough.

Just smooth off sharp edges a little.

That depends entirely of the rest of the engine. For a stock 1600, 7.3:1 is factory stock CR.

For a stock engine, a few grams of difference is acceptable. Mahle has produced sets with *exact* weights. Same tolerance for connecting rods. I match them within 1g but factory spec was 8g difference... which to me sounds a lot.

Advanced head work, that isn't really needed on stock engines. It means removing head material from the combustion chambers, where the "wall" is right next to the valve, preventing flow.

Yup.

Jan

Reply to
Jan Andersson

Again,

Thanks Jan

Matt S

Reply to
Matt S

If you are street driving the Mahles are fine. However the balance is typically +/- 4 gr. This too is ok for a street engine, but as long as ou have them in your hands I would take a die grinder and a good scale and get them +/- 1 gr. Do your Rods at the same time.

Jim SR Racing

Reply to
Jim

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