Deck Height with Euro Flat Top Pistons, Was: Engine Assembly Questions Options

[Jake Raby]

Ernie,
The chamber looks unaltered..

They may be indeed 59ccs, but if they are they will be the largest unaltered chambers I have ever heard of....... Not to say it can't happen but its not ordinary..

The "dimple" in the face of that intake valve is probably good for 1cc by it's self.....

Those sodium filled exhast valves make my teeth chatter all the way here in Aircooled Heaven....... Ouch

[MarkV]

Ernie,

Mine measured 57cc's using a syringe. I sealed the Plexiglas to the head with some grease and had a hard time getting an accurate reading. I bought a titration burette to try to get a more accurate reading.

You said flat top piston but the photo you posted had a dish that you need to allow for. I think the stock 73 piston has a 5cc dish. My pistons are KB from Jake and they have no dish whatsoever.

[MarkV]

Here is a flat top piston:

[ThinAir]

I got my P&C set from a club member who said they were brand new Euro pistons that he didn't need because his project had changed. The part number on the side of the box is 039-198-075, which matches the Euro p&c set at PP. They are definitely "flatter" than the stock pistons that I pulled out of it - the stock pistons have rather steep sides and a flat bottom to the dish.

[Jake Raby]

Yep... Those are flat tops all right!

57cc is normal for a 2 liter chamber.

I have been working on a Type 4 head cc kit and deck height tool as well to make it easier to measure those puppies..

[ThinAir]

So if I measured incorrectly (which seems likely) and it really is 57cc, then I would need a .060" shim to achieve 8:1 compression. This seems more likely.

My measurements were done using a 10cc medicine syringe. Given that I had to do 6 refills in order to get enough fluid into the chambers, I think it is entirely possible that I'm off by 2cc. One chamber measured 58cc the first time I checked it.

Jake - maybe we should change the order or we should talk tomorrow morning (or pm me).

[Jake Raby]

Ernie, You really need to get a 60-80cc syringe. It is very easy to goof up with the process if you are maxing out the syringe 6 times to get the volume you need to work with.

You can normally find one of these syrings at a tack supply store for Horses or a Vet office... Most Human medical suppliers don't carry these big daddy syringes.

Get accurate measurements and I'll hold your order till you do so.

[ThinAir]

Sounds good. I'll recheck and let you know.

Now get some sleep! Isn't it well after midnight in GA?

[Jake Raby]

Midnight and beyond is when I'm most efficient....
\
Crashed at 0315 and back at it at at 0830!

Hell, that was an early night!

[type47]

i don't mean to undercut Jake or any other vendor but this was found on a site that supplies lab equipment for public schools. there are other suppliers.

http://sargentwelch.com/product.asp_Q_pn_E...ts%2C+Basixs_E_

[Jake Raby]

I could care less about the cost of the syringe it's self.. What makes my kit nice is the plates that are made to fit a Type IV engine in various bore sizes.

[Dave_Darling]

QUOTE (ErnieDV @ Apr 4 2005, 08:51 PM)

I got my P&C set from a club member who said they were brand new Euro pistons that he didn't need because his project had changed. The part number on the side of the box is 039-198-075, which matches the Euro p&c set at PP. They are definitely "flatter" than the stock pistons that I pulled out of it - the stock pistons have rather steep sides and a flat bottom to the dish.

Note that there are two different versions of the "Euro" pistons. One of them is truly flat-topped, and one merely has a smaller dish than the US version. The "smaller-dish" version seems to be the original variant, and the flat-top is later. Both will supposedly give you an 8.0:1 compression ratio if everything else is exactly as designed from the factory. (Which it pretty much never is.) I guess the flat-topped ones are very very very slightly taller than the dished ones?

--DD

[ThinAir]

With the help of a 60cc syringe from the local feed store, and some wheel bearing grease to stick down the plexiglass, I remeasured last night. The head for all the cylinders measures 56cc, not 59cc as previously measured.

Although I knew there could be some innacuracy due to using a 10cc syringe and refilling it 6 times, I'm amazed at how far off it was. Just to be sure, I measured them all twice.

So using the calculations, this means I need .060" barrel shims. This will give me 8.1:1 compression.

Jake - if you see this, I placed an online order for the shims. I tried calling and leaving a message, but everytime I punched in 3 as directed I just got cut off.

Thanks to everyone for their patient advice to help me figure this out. I'm gonna have an extra (IMG:http://www.914world.com/bbs2/html/emoticons/beer.gif) on behalf of the group when it's finally back on the road as a way of recognizing that I could not have done it without you all!

This post has been edited by ErnieDV: Apr 8 2005, 05:01 PM