Best head gasket: cometic vs hks , etc

[bwest]

ARP does say to torque all of their new hardware a min of 3x's to set a 'stretch'. Using their lube its 80ft lbs, 30wt oil, 100lbs. When hardware has heat cycled, no need to retorque. (this is for studs; heads and mains)

when in doubt, you can always call ARP's tech line. They will help you out.

 

[jdub]

Read post #9
http://www.supramania.com/forums/showthread.php?t=27433&highlight

Any of the MHG's are good...the HKS stopper is over kill unless you're running a 500 + HP car. The RA spec is 50 for a Cometic, 30 RA for the others...that reason alone is why a lot of people use the Cometic. There's not a lot of machine shops around that can get the RA down to 30 or less without lapping. You want the RA a low as possible, consistent with the capability of the machine shop. Removing the rivets is really not that big a deal...they are there to keep the layers aligned until installed.

I think the re-torque is a good idea...some think it's unnecessary.
http://www.supramania.com/forums/showthread.php?t=34166

 

[drumminforev]

This guys is recommending that we try to get the RA to spec on our own with a diamond lapping plate?? Hes talking about using the HSK stopper mhg at 30ra. Isnt that what the shop should do.

http://www.supramania.com/forums/showpost.php?p=351317&postcount=38

 

[Mr.PFloyd]

wasn't the cometic the one with the rivet you had to remove while the HKS you didn't? I remember some people not doing this and it led to a leaky HG...

 

[jdub]

You are talking about IJ...and yes a machine shop with the correct equipment can get the RA down to less than 30. The problem is most machine shops don't have the equipment capable of doing so...so, IJ got himself a lapping plate. The diamond paste makes smoothing it down much faster.

Yes the Cometic has a rivet...if people would simply read the directions that come with it, there would be no seal problem because they would remove the rivet

 

[drumminforev]

And according to that other post

"HKS, Titan, Greddy Bead type - Very good, also requires a 30 RA. 20+ psi easily"

Does that mean all hks titan and greddy brand? How much is 20+psi? 21...or 35

 

[drumminforev]

You are talking about IJ...and yes a machine shop with the correct equipment can get the RA down to less than 30. The problem is most machine shops don't have the equipment capable of doing so...so, IJ got himself a lapping plate. The diamond paste makes smoothing it down much faster.

So if i did that how would i know how much material was removed to size the hg, and how would i test the ra

 

[jdub]

Don't put the "chicken before the egg"

The question is how much boost do you plan on running to make a specific HP goal? For 90% of the time, the bead type MHG's are fine...this type is made by several companies. Read this link:
http://www.supramania.com/forums/showpost.php?p=216396&postcount=5

The machine shop can tell you how much material they removed...you need to know both sides (block and head) and add together. That plus the MHG thickness should be matched up to give you the stock compression. The machine shop's ability to measure RA depends if they have the instrument to do so...these are expensive. If you can't tell, choice of machine shop is pretty important.

Might want to do an advanced search here with my SM name and head gasket as the parameters...I've discussed MHG's quite a bit.

 

[drumminforev]

Don't put the "chicken before the egg"

The question is how much boost do you plan on running to make a specific HP goal? For 90% of the time, the bead type MHG's are fine...this type is made by several companies. Read this link:
http://www.supramania.com/forums/showpost.php?p=216396&postcount=5

The machine shop can tell you how much material they removed...you need to know both sides (block and head) and add together. That plus the MHG thickness should be matched up to give you the stock compression. The machine shop's ability to measure RA depends if they have the instrument to do so...these are expensive. If you can't tell, choice of machine shop is pretty important.

Might want to do an advanced search here with my SM name and head gasket as the parameters...I've discussed MHG's quite a bit.

I will be close to 500crank hp. A little less maybe. So what im reading says that the $300 hks metal stopper hg is neccessary for that...

 

[jdub]

The HKS Stopper is no doubt the best...it's also the most expensive.

When you start talking about 500 HP+, you are also talking about big $$$. You will need a capable turbo, IC & piping, forged pistons, billet rods, machine work to fully turn, line hone & balance the crank, additional head work, mods for fuel, plus more....it adds up fast

 

[drumminforev]

The only thing im not sure what you mean is "line hone"? By machine work and head work you mean p&p, fresh valve job, anything else

 

[drumminforev]

I figure i can build for close to $6000 - $7000 This is how i figure:

This is how i figure:

1985 mk II car - $300
bhg 7mgte - $500
hks head gasket - $300 hks stopper
r154 tranny - $300
custom driveshaft - $200
11lbs flywheel - $140
spec 2 clutch and PP - $400
turbo - $900
Pistons and rods - $1100
titan spring and retainers - $250
valve job - $100
balanced crank - $100
P&P - $300
injectors - $300
fuel pump - $100
intercooler and piping - $200
accusump - $250
sequntial bov - $150
dyno tuning - $300
oil psi & boost gauge - $100

That puts me at $6300.

 

[TurboWarrior]

Does the titan have the rivet? I hope the machine shop read the instructions

 

[jdub]

Line honing aligns crankshaft main housings perfectly straight, round and true to each other. Aftermarket main caps can be fitted to blocks (if desired) when this is done properly.

Well...$5K is a good start. Consider forged pistons are $500+, billet rods are over a grand, a Boss bolt-on turbo is in the $1500-2000 range. Then you've got all the supporting mods for making this kind of power. Quality machine work is not cheap either. Your estimates are on the low side.

Take a look at my profile...I way over built my motor. Why? I want it to last.
BTW...it also took me quite a bit of time to build this motor doing it myself. cash does become an issue

 

[drumminforev]

Will a piston and rod set like this be quality and capable?

http://cgi.ebay.com/ebaymotors/EAGL...016QQitemZ260077270655QQrdZ1QQsspagenameZWDVW

 

[jdub]

That's a very good price
Alamo Motorsports is a trustworthy vendor as well.

Wisco pistons are nice...come from the factory w/ coated skirts. Keep in mind Wisco pistons are actually a 9.1:1 compression ratio...8.4:1 is stock turbo compression. You might want to consider a 2.0-3.0mm MHG to lower the compression a bit, especially if you plan to boost above 15 psi.

Eagle rods are better than stock, but you might want to do a search on them. There are issues concerning journal sizing iirc...I don't have personal experience with these rods.

 

[drumminforev]

Line honing aligns crankshaft main housings perfectly straight, round and true to each other. Aftermarket main caps can be fitted to blocks (if desired) when this is done properly.

Well...$5K is a good start. Consider forged pistons are $500+, billet rods are over a grand, a Boss bolt-on turbo is in the $1500-2000 range. Then you've got all the supporting mods for making this kind of power. Quality machine work is not cheap either. Your estimates are on the low side.

Take a look at my profile...I way over built my motor. Why? I want it to last.
BTW...it also took me quite a bit of time to build this motor doing it myself. cash does become an issue

Besides the turbo, what else would you add for me to "overbuild" - parts and prices. Because I do want this to last and will spend the extra to make it happen.

 

[jdub]

Keep in mind, you're asking that question to a guy who is not exactly the "king of cheap"

Well...I would use:
- Pauter or Crower rods.
- Wisco, Ross, JE are all good piston choices...ceramic coat the tops
- Ferrea valves, springs, and retainers...consider 1mm oversize...don't have experience w/ Titan
- Use a 7M crank vs the 6M crank found on earlier GTE motors.
- MHG is a matter of personal choice...use the HKS Stopper if you're going for the big HP numbers.
- ARP studs on the head (torque to 81 ft/lbs w/ moly)
- ARP main bolts...billet rods come w/ ARP bolts. Torque both to ARP spec.
- New oil pump
- Stock cams or a 264 cams
- Adj cam gears (optional...used to fine tune valve timing)
- Complete Toyota gasket kit...a lot of guys have used the Fel-Pro kit with success
- Boss Turbo w/ stainless lines...61 trim or if you really want to go nuts, a 67 trim
- Single piece downpipe w/ flex section...your choice on who makes it
- RC 550 injectors
- Spearco IC flowing 700-800 CFM w/ 2.5" inlet/outlet and 2.5" metal piping to throttle body
- Lex AFM or Maft Pro running speed density. Or you could go w/ a stand alone EMS
- Wideband O2
- EGT gauge w/ sensor on the turbine housing
- Aeromotive FPR w/ stainless lines...bypass the "J" tube and remove the FPD
- Upgraded fuel pump
- MSD wires w/ NGK iridium plugs
- Bigger oil cooler
- Remote oil filter w/ dual head...Wix & Trasko oil filter
- Ceramic coat exhaust manifold, turbine housing, and downpipe...2000 deg rated coating
- CSF dual core radiator...you need this in AZ...trust me


Machine work:
- Bore to .020" over size using a torque plate
- Piston clearance on the tight side of manufacturer spec
- Gap the piston rings
- RA spec on block/head deck to 30 RA (at least)
- Machine front timing cover to match block deck height
- Line hone
- Turn & balance crank
- Balance pistons and rods
- Clevite rod and main bearings and thrust washers (sized to your crank...tight side of spec)
- Check sizing on new rods and match to crank/bearings
- "Street" P&P head
- 5 angle valve job, new seals, replace guides as necessary
- Replace exhaust manifold studs...helicoil exhaust stud holes on the head

This is just off the top of my head...looking at some of this, I see that prices have dropped...that's good for you
You'll have to get the pricing on your own.

 

[yaitsme]

:bigthumb:

That's good stuff Jdub ...
+1 for hanging in there through all those posts!

 

[Doward]

You forgot lighten and knife-edge the crankshaft