Bhg

[CanadianBak'inSupra]

man i love reading all your threads thanks for the knowledge!!!

[cvbikeguy]

Originally Posted by CanadianBak'inSupra

man i love reading all your threads thanks for the knowledge!!!

lol its nice to know my pain and struggles can be of service to someone else .

id rather post all my problems to help others that are going through the same thing. once i start hacking away ill post up picks. ill also do that for when the interior comes out (i think im just walking into trouble) hope

[cvbikeguy]

Originally Posted by cre

No, you'll use the stock size bolts. You're not tapping the holes any larger, you're tapping at their current size to just clear out material which has swelled and to reshape them so that the bolts can go in without any resistance which would skew the torque readings.

Make sure to THOROUGHLY lubricate the bolt threads with a good moly based lube. If you used moly lube prior (you should have, if you didn't there's major mistake #2) you can soften it up by massaging a little oil into it, but I'dd add some fresh grease too.

tighten in the correct order in multiple passes. I generally torque in 15 to 20 ft lb increments. First pass @ 30, second @ 45, third @ 60, fourth at 75. If I'm using studs I'll do it that way up to 90 (did last night in fact).



The tap length doesn't matter, but they're fairly standard. You want one the same size and pitch of the stock head bolts. A bottoming tap is even better but they're a lot more expensive. Unlike a taper they'll cut evenly all the way to the bottom, but it isn't critical here.

Buy or borrow or rent a machinist's straight edge and check the block and head for warpage as shown in the TSRM. Make sure the lower rear timing plate's deck does NOT sit any higher than the block's deck!!!! If it does it will keep the head from coming down all the way and evenly.



Absolutely not!

moly and grease on the threads?

Originally Posted by cre

Wikipedia has some good info on the different types and how they work.

http://en.wikipedia.org/wiki/Taps_and_dies

wow im sorry to say that i failed to check that. wiki is my middle name

thanks cre. who knows possibly in a couple months i can actually get this running

[cre]

http://store.driftmotion.com/static/i-tap12x125.php

As for the moly thing... torque values vary depending on the type of lubricant used. Where a fastener may only require 90ft lbs with a good moly used to luge the threads it may require as much as 130ft lbs if only lubed with 30 weight oil.

[MA70-3.0GT]

Damn sorry to hear this man, I'd just cry. (I'm pissed off enough just having an oil leak from the turbo after reassembly!!!) think it's pretty much been covered here in that the threads need to be as clean as the rest of the job really if it's gonna hold. I cleaned mine with a combo of 2 stroke oil & an old bolt with slots cut up the length of the thread in the same fashion as a bottoming tap but obviously with the small advantage of only removing crap not fresh iron) & after that blasted them out thoroughly with brake cleaner until a rag on a screwdriver came out of each hole clean. Also I took a clean bolt & made sure it went in by hand with the same force, right to the bottom of each hole with no sticky bits. Then plugged the holes with blue roll until I was ready to throw the head on. In short the holes need to be good for eating your dinner off & then some.
Also if you're reusing bolts after any time or a HG blow make sure (ideally with a die nut) that the threads on those are perfect too. As cre mentioned you wouldn't believe how little crap or even just a different lube can affect torque readings opposed to clamping force...

Oh one more thing I didn't notice mentioned was the dowels front and back, their holes also need to be clean & the surface of the dowel perfect or the head could potentially stick on those. Front one on my motor had to be swapped as it had been mauled & burred by the gorilla that did the last rebuild so professionally . 90ft/lb by the way is what my stock bolts are at right now, if you have ARP 100ft/lb would be my choice for peace of mind (and obviously a retorque after 150/200miles max.).

Best of luck for take two, for once I'm gonna hope it's NOT 3rd time lucky!!!

EDIT-: Oh cre, on the subject of hollow studs surely one could have ARP's or even stock bolts drilled part way up to create the same effect (I'm thinking simply as a place for any remaining shit to go, instead of it hydraulicking up under the base of the stud/bolt hence making it feel tighter than it is) provided it was done accurately & not on a hand drill & vice of course!

[cre]

A blind 20% bump in pressure is way too big to go and just recommend to everyone. The reason for the jump from 58 to 75 is that 58 is a commonly used torque value for cast iron heads. 75 is used in most things aluminum (your wheels, for example). People far more educated on matter than you and I came up with these values, their warranties are based on these values (yes, they will be able to tell). The head isn't as beefy as people like to think and the bolts and studs aren't immortal. Any, I'll reiterate that the value also depends on the lubricant used... if you're using 30 weight oil, your about right on... moly... well, whoops.

You can't really drill fasteners without compromising their elasticity. There's no way you're going to keep them cool enough for starters. And it has nothing to do with creating a vent, it's for measuring stretch and calculating the real clamping force.

The dowels are not considered reusable actually... no reason they shouldn't be except that they're tapped into the block and getting them back out requires either pounding then in the rest of the way so they fall into the coolant passages or mauling the living hell out of them to pull them out the top. This came from a Toyota tech, there's nothing in the TSRM on the matter as they don't expect you to remove them at all.

[MA70-3.0GT]

Good point well made & no I wasn't really considering the use of moly lubes (which I now note you recommended earlier) as I'm a cheapskate (read blind-skint!) and my 90 on stock bolts was achieved using 2t oil IIRC. I wasn't really recommending anyone else go for 100 on ARP bolts mind, just observing that if I had fitted them I would have probably gone that far (but then I guess if I could afford ARP bolts I could afford decent assembly lube also so maybe not...)

Again good point on drilling of fasteners, looks like someone's not really got their brain in gear yet today... Think a beer or three might get me cogs turning again... (Am I gonna end up famous for saying "it seemed a good idea at the time" some day?)

Anyway I got the hint that the dowels aren't really intended to be removed by the way said lump was mauled at the front of my motor, I'm still cursing the now defunct total-engine ltd! but it's still gotta be worth remembering that the holes in the head have to be clean too & checking the same bodgery hasn't happened as mine resulting in a burr that the head could sit on, and the 150/200mi retorque is essential IMO no matter what anyone says it's a hassle but what price being sure it's not settled?