raverx3m

iTrader: (1)

ive been looking everywhere cant find them

gsr block have been cut too much to get rid of the rust on the top now its at 211.73 and deck clearance is only .009" with any aftermarket pistons. and I think I need more than that with pro2 cams

all the pistons I can find are 30mm compression height.
the only ones are not is stock phk but they are not 84.5mm

Muckman

iTrader: (2)

Nobody makes self pistons with a lower compression height. You'll have to go custom. I wouldn't hesitate to run a thicker Cometic head gasket for resolve your issue.

raverx3m

iTrader: (1)

I found endyn and few other brands have the 29.xxmm compression height but they only go up to 83mm and phk are ony 84.25mm lol.

what thickness would you suggest for headgasket with those cams?

its a gsr block with itr crank/rods. stock gsr head and valves arp headstuds and rod bolts

everywhere I read people say to have at least .030" clearance but then I put together a gsr with CTR pistons and it gives me .006" piston to deck clearance. which is less than I got and I saw few threads people saying they ran pro2 with that clearance.

with a .05mil headgasket I only get .011" clearance.

I didn't have to deal with this in previous builds besides what I red here about .030" minimum clearance I don't know much about this.

are people including the headgasket in that number or is that actual piston to deck clearance before the headgasket. I found one confusing thread about it and that it

darnizzle8805

iTrader: (1)

Piston to deck and piston to head are two entirely different measurements. Your best bet it to assemble your block, measure the piston to deck height, make sure to rock piston front to back and average the number, place clay on top of the pistons, install the head WITHOUT a head gasket, torque the head down, remove head, and measure the clay, order a head gasket with the proper thickness to ensure the proper clearance.

The only way to ensure is to measure everything, as we all know the manufacturer can list one number as spec, and the end user find out the spec is different. (Cam lift and duration for instance)

Muckman

iTrader: (2)

Yes people are including the head gasket thickness in the p2h clearance. The OEM HG is .027~.028" alone. I dont feel comfortable under .035" p2h. You can measure your p2d then add the crush thickness of the head gasket to get the p2h clearance.

If you want to restore the original deck height use whatever thickness head gasket gets you there. You can measure the depth of the 3 dimples in the corners of the deck to measure how much was milled off. Stock depth is .037~.039".

Regarding your p2v clearance with the Pro2 cams, I don't know. Frankly you shouldn't run the cams without measuring the actual p2v. Your trying to determine safe p2v from p2h alone. You're also forgetting about v2v clearance. Pro2 cams are def not designed to be drop in cams without measuring these critical clearances.

raverx3m

iTrader: (1)

the machine shop wrote down the deck height. its 211.73
ok thanks that's what I was trying to figure out all day today reading the threads lol
people are confused when they referring to this. in a lot of threads
they say piston to deck clearance when they mean piston to head clearance it seems like
if im getting the .009 piston to deck that means with a .035" headgasket it would be almost back to stock clearance. and I am measuring all the cam related clearances also.
that I always measure
I made that zip tie thingy few years ago with clay on top of it to slide through spark plug opening without taking the head off so its even easier to measure the p2v clearance

Muckman

iTrader: (2)

Ignore the deck height measurement. Its irrelevant, just measure the piston to deck height like you are. Make sure you measure on the exhaust side and only rotate the engine in the natural rotation (counter clockwise for B/D series).

Stock piston to deck height (unmilled) is .033". Thats a lot more than you have.

I want to see a picture of your zip tie clay thingy.

raverx3m

iTrader: (1)

raverx3m

iTrader: (1)

You can see the indentation from the edge of the valve too.

i used playdoh but im sure theres better compound to use as playdough sticks to the valve unless i put some oil on it. but oil breaks it down so use vaseline lol

wantboost

iTrader: (2)

Is there any particular reason you have to use this specific block? Is it sleeved?

If not just find a block that hasn't been decked as much. Unless your order custom pistons and use a fairly thick HG you'll never get the clearance numbers back to where they need to be. It would be much easier from a time and frustration point of view to use a different block.

raverx3m

iTrader: (1)

Its sleeved block that i got for 300 bucks and i just spend another 300 to get it bored to 84.5
But it was just confusing about clearance.

B20vtec piston to deck clearance is actually same so with thicker headgasket i should be fine

raverx3m

iTrader: (1)

so I was searching through some threads here and saw that someone measured YCP pistons and they were 29.7mm compression height instead of 30mm.

and also it has different dome height compared to rs machines that both claim to be type-r replica. why are they different specs?

is that confirmed or just one off piston that he measured?


I couldn't find info on any other pistons tho