forcefedeg01

Here's the rundown on parts. B16A block 81mm, stock rods (arp bolts), RS Machine B16B (PCT) pistons with a OEM honda headgasket and GSR head. My problem is, I torqued the head down using golden eagle headstuds and the pistons are touching the head, thus not rotating. I've seen this done on hundreds of b16's using honda b16b and rs machine b16b pistons and yet to hear any problems.

Would it be the GSR head that is causing this since, from what ive read the gsr chamber is different, or what?

I already did one a long *** time ago and didnt run into problems, but this one is kicking my ***. from what i can tell it looks like its hitting on its piston dome sides ( by where the lil arrow is at and opposing side and nothing else.

Any help would gladly be appreciated. i thought of mayb a lil bit thicker headgasket or maybe b16 head swap.

Help me out HT community i need this engine in asap.

Thanks

SL0WEGG

If you're having clearance like that. You're def gonna need a thicker head gasket. Did you ever check piston to valve clearance?

JDM JEFFREY

iTrader: (1)

Is this going to be a street motor?
If so would look into getting
Jdm p30 pistons
Ctr pistons are going to be 13+ cr

EG1834

Get some clay or some play-doh and apply a layer to the top of the piston. This way you can see where it's hitting and how bad.

If it's bad, you may be better off machining the pistons.

Colt Seavers

The piston hits the head because the compression height on a b16a is 20 thousands under the deck and b16b is 30 thousands under the deck, so they stick out of the b16a block ten thousands. Just get a thicker head gasket, and you will be fine.....

forcefedeg01

well the block did get honed and resurfaced which i know its same as decking it. but the ding bats at the machine shop didnt specify how much they took off which sorta pisses me off. the motor is a friend of mines im putting together but i didnt know if the gsr head with the smaller chamber at valves would matter.

77amc

Where did the block come from? Previous knowledge of it?
Over-heated blocks tend to warp an open deck at times.

If they're a reputable shop, they would of told you what was taken off.
Or you may want to talk to the piston mfg and get all your numbers together: Crank centerline, bearing thickness, pin dia, piston compression hieght and measure that against the block from deck to center line. If its' way lower than a stock deck then.. They owe you another block
BUT, try and corner them with that.

E

00Red_SiR

PCT pistons don't like GSR heads, PR3 heads tend to be better for that combination. Machine shops only do so much but it's often up to the builder to check all clearances at the time of assembly.

EG1834

Did you get a build sheet? There is usually a "deck clearance" specified which is how far the piston is above/below the deck surface. With the stroke, rod length, and compression height that should give you an idea as to how much was milled off of the deck.

Then compare that with how thick the stock headgasket is.

I'm assuming that since you say you torqued the head studs, that you are the one installing the cylinder head. Did the machine shop have the head when they machined the shortblock?

Very good point.

forcefedeg01

yea they had everything, im the one assembling the motor. ill check how far the pistons stick out the block, cuz it does a lil bit

EG1834

From what I've read, the OEM gasket is only about .029" thick. If the piston is set above the deck, you may not have enough piston-deck clearance. Most builders shoot for about .035-.040" with steel rods.

forcefedeg01

yea the lip around the piston does sit above the deck surface of the sleeves (stock sleeves) but idk how far out yet, havent gotten a chance to get in the garage with workin alot. i would think a thicker headgasket will fix the problem correct? or am i ef'd and cant do anything about it?

raverx3m

iTrader: (1)

gsr head quench area is different fron b16/type-r

heres the image( tha arows are pointing to the spots)




and btw, i got a OEM headgasket kit(stoner? or stone)) the headgasket is only .022

EG1834

Do you have a deck bridge to measure accurately?

EG1834

Yeah, there will certainly be issues if the piston is out of the hole, and the headgasket is only .022" thick.

00Red_SiR

The gasket should be .026" thick, crushed. .022" sounds like it's a 2-layer hg before it's compressed.

forcefedeg01

wth is a deck bridge lol. i've never heard of it.

forcefedeg01

oem honda purchased 3-layer is what im using

00Red_SiR

that should be .029" new and .026" crushed.

EG1834

I bought mine from powerhouse tools, which is a division of Comp Cams. IIRC, they're pretty cheap.

raverx3m

iTrader: (1)

yea the gasket i got was with the rebuild kit, not OEM honda but said to be to oem specs.

its a 3 layer gasket and i measured it at .022. which is fine in my case i need more CR anyway.

damn those pistons are flat

forcefedeg01

we'll imma swing by the garage tomorrow and take some pics of it and post it so you can all see. i've put ctr pistons before on b16's like i said before but never ran into this issue. i see how the b18c and b16a heads have different designs now. ive never touched a gsr head before since all ive run into were b16a's to do valve springs and such. ill post pics of it then so you can all see and hopefully help me out. I'm a turbo honda guy and this is the 1st time i run into this with an n/a..

thanks alot tho people for all your comments and helping out btw.