What else to do when machining head?

[rob21a48422]

So I'm in the middle of my first headgasket replacement and I was wondering what else should I do to the head while I've got it out and torn apart. I'm using ARP studs and a Fel-Pro gasket to put it back together and I don't plan on exceding 14psi. I'm going with a Fel-Pro because I don't want to pull the block out and start messing with it. Aside from new cam and valve seals what else would be a good idea to do right now. I'm not looking to go all the way and do a port & polish or 3-angle valve job yet. I'm trying not to spend a ton of $ on it because I'm hoping to go 1JZ or 2JZ at the end of next summer. I'm simply trying to insure that I don't have to tear anything apart before then because of a simple overlooked step or procedure. I've got a complete engine gasket kit so I'm replacing all the gaskets as I go as well. Also, is there anything SPECIFIC I should tell my machinist before he does anything to the head? Thanks.

 

[AF1JZ]

I would honestly go with a Cometic HG instead of the fel-pro. Only reason is the RA specs aren't as high as it would be with other MHG's. Other than that, the HG and ARP bolts would be good. I'd have him check the condition of the head as well. GL.

 

[jdub]

- Make sure the block is flat...clean the deck very well...clean the carbon off the cylinder tops (Mopar Combustion Chamber cleaner).

- The head has to be in TRSM spec for flatness...even if machined, the top of the head can have a "banana" to it.

- Keep the valves, springs, retainers, lifters in order...have the springs tested by the machinist for proper compression force. I would reconsider having a valve job done...this is a really good time to do it

- ARP studs are good...use the ARP torque spec.

- Don't forget the RTV sealant at the top of the timing plate...location is in the TSRM.

- IMO, using a composite HG is fine for the boost levels you're looking at. Yes, the Cometic is a bit more "forgiving" on RA spec. But, you're still taking a crap shoot as to if it will seal in a block that has not been decked.

 

[rob21a48422]

I'm going to be using a Felpro composite gasket and I won't be pulling the block. I will certainly clean it up the best that I can while it's still in the car but I thought you could use Felpro and other composite (not MHG) gaskets without decking the block?? Is this not true? The engine hasn't been overheated so I'm hoping or assuming the block isn't terribly warped. I do know that pulling the whole engine and decking block and head and using a MHG is the best route to go but I'm not looking to do that, just get the car running well enough to hold no more than 14psi until summer, when a 1JZ or 2JZ swap will be performed.

 

[starscream5000]

The composite HG will help seal a less than ideal mating surface between two dissimilar metals, but it is not guaranteed as you don't know how far out of spec the block is without checking.

 

[IJ.]

Hardness test before you spend a single cent on any work....

 

[bowsercake]

I'd get a valve job as well. They can do a compression test to see which valves are leaking (probably all of them are).

 

[Shytheed Dumas]

VALVE GUIDES AND SEALS!!!! 18k miles after doing my HG and blowing smoke so bad I took her off the road last week. Get it done for easy insurance.

 

[GrimJack]

What IJ said.

Then get the flatness checked on the cam saddles. Many shops will machine the bottom flat, but if the head was warped to begin with, this will leave you with a flat sealing surface and warped cam saddles. This leads to thrashed cams in short order.

Get the exhaust side manifold stud holes helicoiled.

Valve seals for sure, the cost is so small you might as well.

Even keeping the parts for each valve together, remember to recheck your valve clearances afterwards, chances are some will be out.

 

[NewWestSupras]

I'd also buy the set of new SBC Comp Cams valve springs i have for sale cheap.

 

[gtsfirefighter]

Having the work done by someone familiar with Supras would be a big +.

 

[selfinfliction]

for a rebuild of the entire engine (nothing broken, just building to hold some power), the block and the head need to be decked for the mhg?

and for this application, is decking the block the same as we zero blocked the decks on our v8's? do the mhg's compress any at all? if so, does that shrinkage need to be calculated into how much the block/head is being decked?

sorry if these are retard questions, i've never had to worry about having an mhg before even on my other car that's pushing close to 19psi (not a supra)

 

[Poodles]

valve guides aren't worth replacing unles they're trashed

valve stem seals YES

valve job YES

helicoil exhaust studs YES

ensure the head it straight before surfacing CRITICAL (worst case the cams can seize)

Comp Cams valve springs are cheap and effective, I run em and the engine is very strong, plus they're far cheaper than stock and are an upgrade