I have a small problem with the engine i'm building, my boss who is an engine machinist checked my piston to deck height and noticed it to be 0.100" below deck. What I need to know is: Is it bad if GE were to install sleeves and take out that 0.100" section on top so the pistons are perfectly level with the deck and still have the block be just as strong? Also I have Arias pistons for an 84.5mm bore. The piston clearance is supposed to be 0.002", but the instructions also say to subtract 0.002" from clearance number if pistons are pro-coated, well I just got my pistons back from Swain-Tech so now my piston to wall clearance is 0.000"? -Jeff P.

 

id say when u install the sleeves that u have to recheck the deck height b4 u even continue. with the stuff ive read (dont have personal experience) u need to re deck the block after a sleeve install anyways, just to make sure everything is A ok. as far as the piston to wall clearance, just re hone it a bit more. it wont take long to take out another 2 thousanths.

 

Are you sure the rods are the right ones???

 

Well I have a B20B block and I also have custom made rods for my engine, there length is 142.45mm. Now the kicker is I have a crank from a B17A engine and that length is 81.4mm, I also have custom made Arias pistons as well with a compression height of 1.175". As you can tell, I have a combination of different factory and aftermarket components for my engine, perfect fitment is not likely to happen and I knew this, but I need to know if decking the block down a big whopping 0.100", will the block still be strong enough for high rpm and boost. I think this is likely, I have seen a B16A block and I can see that its deck height is WAY shorter than mine, since b-series castings pretty much come from the same castings (granted VTEC and non are different castings but you get the idea) they get machined at different deck heights for different models (B16A, B17A, B18C1, B18C5, B18B, B20B4 and hell the B20A). So what is your input? Its going to be at a different deck height-just not from the factory. -Jeff P.


[Modified by Casper1379, 7:19 PM 6/11/2002]

 

ttt

 

Wow what a combo...
Where do I start?
First of all, you are forgetting something, if you deck the block by .100', you will have trouble getting the timing belt and cams to be in correct time. Minor problem... Also don't forget about the bracket holes not lining up without some modifications.


One good thing about your crazy combo is that your rod to stroke ratio will be higher than a B16! It will be 1.75 VS the B16s 1.74! Great for turbo or high rpms!!! But you probably already knew that I'm sure...

You say they are custom made rods? Why did'nt you get rods that were .100" longer if that is true? Custom pistons too? Custom means you tell them what you want, and they make them to your specs... so if you did, why do you lack .100" from the deck? (Now tell me what the rods are really out of.) Are they out of the old B20A motors? Because they are 142.75mm
So what you are telling me is that you need a rod that is or 144.9896mm (145mm)or 5.70" to get exactly a 0 deck height correct?

If you are running forged pistons on that size bore, you'd better go with no less than .003" piston to wall clearance if you want it to last any at all!!! And if you are going f/I, you need .0035"!!!


BTW, decking the surface of the block has no effect on strength, it just makes things not line up properly!


Give us more precise info and we may be able to help more!!!


[Modified by Mochanic, 6:07 AM 6/13/2002]