Replacing Rb26 Head Gasket. Questions!

[Nameless EJ6]

Hi all. I live in the US.. I have a 97 GTR motor that I'm prepping to put into an S13.

Right now, I've got the head removed and I'm looking for some answers regarding the head gasket.

I will likely go with an aftermarket HG. Anyways.. here's some questions. (I searched quite a bit) These are aimed towards people who have done many headgaskets. Tuners, engine builders, technicians, etc.

- Is it ALWAYS a good idea to resurface the head before putting a new gasket on? Or are there certain exceptions?

- If NOT resurfacing, what should I use to clean/prep the gasket surfaces without damaging anything?

- If material from the OLD gasket falls into the ring gaps (hard to avoid this from happening), will blowing it out with an air compressor be sufficient? I don't want any damage to the cylinder walls, or crud stuck in the ringlands. I'm not dissasembling the bottom end.

- I've been reading about oil feeds between the block and head. Some people plug one of them up? Not sure about that. But since this motor will be intended to be boosting at higher levels, should I do any plugging of orifices between the block and head for prevention?

- Last question. There is some combustion leftovers on the tops of a couple of the pistons. Is it ok to clean this off? And how?

THANKS!

(btw, here's a picture of the motor)

Edited October 12, 2005 by Nameless EJ6

[Nameless EJ6]

wtf. 27 views and no replies?

You guys must like pictures.

[Craved]

I will likely go with an aftermarket HG. Anyways.. here's some questions. (I searched quite a bit) These are aimed towards people who have done many headgaskets. Tuners, engine builders, technicians, etc.

(btw, here's a picture of the motor)

<{POST_SNAPBACK}>

im guessing that this is why you have had a lot od looks and no replies ..

most people on here aren't engine builders ...

neither am i .. but if your building a high power RB26 .. i would suggest getting the head dechek to make sure its straight .. esp with a metal head gasket. while its getting decked, have them clean/bath/dip the head to get the carbon off it.

you will still need to clean the block with a blade and metho/turpentine to help get it clean.

if anything fell into the bore... i doub't it would go far into the gap between the piston and bore.. but blowing it out would be fine in my opinion.

oil feeds .. pretty sure that the RB26 already has one blocked.. a better idea would be to get the return drill out bigger to allow the oil to flow down better -- this recommended if it will be revving hard all the time.

if you dont get the head cleaned .. try carbie or contact cleaner .. works well on this sort of deposite

hope this helps you a bit!

Craved

[pnblight]

ok i would think it a good idea to surface the head, it will help the head gasket to seal (remove only what you need to clean up the surface) if it takes a bit to mill the surface you might want to compensate with thinker head gasket(the machinest can tell you how much he removed), as for the block, scrap of leftover gasket material (carefully) and you'll need a good oil stone to rub down the surface keep the surface wet with something like CRC while your rubbing it down. Then clean the surface with and to remove any gung from the cylinders apply a thick ring of oil around the top of the cylinder then turn the engine over, the oil will be pushed to the top but should catch any foreign material.

It is a good idea to fit a tomei oil gallery resistor to the block they come in the tomei head gasket kit and simply knock in on top of the exist one (simple) There is only one

It will be fine to clean the tops of the pistons i would do that first.

pete

hope it helps

[PHATR32]

on the few engines ive built up, i found using some gasket stripper cleans the crap of the pistons real nice.

u spray it on and let it sit for a few minutes. then wipe it off.

steve

Edited October 14, 2005 by PHATR32

[Nameless EJ6]

Awesome, thanks for the info.

I'm planning on keeping the motor relatively stock. My goal is between 400-500hp... and this isn't a daily driver so it'll only get weekend attention.

I guess I'll go check out some reputable shops that are experienced with resurfacing heads. I'm going to check it with a straight edge though.. because if it doesn't need to be milled, then eff it.

I'm not sure about having the head dipped for cleaning. I don't want to remove the valves, but I'll determine that after I make some measurements. I may replace valves and guides.

I'll try the gasket remover on the piston tops for sure.

Any other postings would be appreciated. Thanks 4 the help.

[Craved]

i ahd the head on my car cleaned when it was shaved ... didn't need to remove the valves ... just have to make sure you put enough oil back in the top of the head before you try to start it up again!

but yeah just check it with a straight edge and save yourself a bit of money if its not required..

[CRSRB25DE]

If you are using an aftermarket multi layered steel gasket it is highly reccomended you surface the head as flat and smooth as possible.

I personaly like to machine every aluminium head when the head gasket is replaced.

(Im an engine recon'r so i do it every day)

Save any trouble in the long run.

Chris

[T04GTR]

i agree.

head surface should be skimed. quite a long head will always have some degree of warping in it. sometimes they are ok. but for a 100 bucks its better safe than sorry.

tomei oil restrictor.

3m pads (hand ones)should remove the carbon from the pistons with a good solvent)

carfuly remove the dowls and with a oil stone rub it down.

avoid getting shit all down the oil feed.

dont air blow the pistons it will drive the carbon/gasket material further into the rings. use the oil trick(a nice thick one) to remove most of the stuff.

hylomar all surfaces.

probably a good idea to check the valve guides. both for ware and bits missing.

(the head shop can check this for you).

about half of the 26 heads ive pulled of have bits of the inlet valve guide mising

happy thrashing

[gtrgodzilla]

ive been told that the standard oil feed hole is 2.0mm and that this is to large when at high revs(over 8500rpm).most restrict it back to 1.5mm so that more oil stays in the sump and around the crank.

hope thats some help to you!

[Nameless EJ6]

Thanks guys.

I went ahead and used some gasket remover to dissolve the carbon deposits on the tops of the pistons. Worked pretty good.. but I did assist with scrubbing them a bit with a 3m pad. They look nice now.

Can anyone locate me pictures of the oil feed holes? I am definitely going to use the tomei restrictor

[Gav]

Thanks guys.

I went ahead and used some gasket remover to dissolve the carbon deposits on the tops of the pistons. Worked pretty good.. but I did assist with scrubbing them a bit with a 3m pad. They look nice now.

Can anyone locate me pictures of the oil feed holes? I am definitely going to use the tomei restrictor

<{POST_SNAPBACK}>

Only one hole needs to be restricted - see below:

[pnblight]

gav you the man .

where did you find a diagram like that

good shit

pete

ps guys fit this resistor (it a must)

[siksII]

I used a scraper i got from a hardware store to clean pistons in an rb25, they were very crusty so went through like 3 scrapers for 6 pistons

I moved the piston i was cleaning to TDC when cleaning it to not get crap in the bores, just do that.

I have added some pictures for your amusement

Edited October 25, 2005 by siksII

[Beer Baron]

pete, that diagram is on the tomei website.