Another "Stroker" Project

[Audi_CQ]

Your going to take a stroker on a 95.5mm crank above 7500rpm?

If you take it above 7000 rpm during heavy during i'd be shocked

7000+ isn't a problem. Wouldn't go much past 7500 on a regular basis, but properly built it will be OK at 7500. Last season alone I logged over 1000km of track use and 7000+ happend regularly (I run with 7500 limit).

[Audi_CQ]

New TTRS Engine with 92,8stroke has a rev limit of 6800 and at this rpm a Max piston speed of 34,6.

Old RS4 / R8 : 92.8 stroke and 8250 rev limit

[Billman]

parts ordered:

3b Oilpump
3b waterpump
ABy Belt
Girdle: 6mm think so a compromise between the 2 (no need for subframe mods-not very think/hardcore) :-)
ARP Head studs
Adjustable Pulley (both)
Volcano Crankshaft pulley
Reinz Gaskets
Glyco sputter

Question: When fitted the piston are on the same height as the block deck or not?

[Billman]

Goodys arrived:
(Double adjustable Cam pulley)

[rash]

...where did you order the girdle?? ..and the cam gear??

[A80Avant]

does anyone remember what is the height of the piston from the block at tdc?(question on behalf of billman).

[AndyP]

On what engine?

[A80Avant]

on a stroker, same spec as bilmmans

[AndyP]

If you check the spec of the piston in post 150, they should be flush with the deck, if the deck is 236mm. This is the figure that is quoted for the AEL block, but if you see post 151, you'll see that mine was approx 0.5mm taller. Checking the deck height is essential, but not easy without the right equipment. HTH.

[Billman]

We have checked the deck height and ordered the pistons for 8,5:1 CR and they are approx. 0.5mm lower than the deck.

[Billman]

we have measured it at 236! In the original block-piston combo the pistons are flush with the deck or what?

[Billman]

In the original block-piston combo the pistons are flush with the deck or what? I want to know a mistake of the machine shop or does it comes like this also in the original!

If it stays like this it would mean that i will have a 0.01042 ccm more combustion volume! How much drop in the CR am i going to have with this? Are there any other issues with that?

[terrybullwon]

Please go and buy a book on engine building your questions are very shakey!

[AndyP]

According to your piston spec is post 150, you have a compression height of 30.25mm. You have 158mm rods and a 95.5mm crank.

30.25+158+(95.5/2)=236mm

So IF the deck height is 236mm, your piston should be flush. If it's 0.5mm below the deck either your pistons are wrong or you've measureed the deck height wrong.

[Billman]

@terrybullwon
thanks for answering my question, very helpfull!!

I believe that the machine Shop measured it wrong! What if I let it like this? Can someone calc the new CR? Are there any other drawbacks if it is not flush?