Bhg

[cvbikeguy]

Originally Posted by cre

Chasing threads is a pretty standard practice. You get a tap (thing used to thread holes for bolts) of the same size and pitch of our headbolts and you thread it into the holes (and keep adding oil to lubricate and clear out debris). As you thread it in AND as you thread it out it cuts the metal of the threads back to the right shape and size for the bolts/studs. Not doing this may cause the bolt to reach a given torque level but not provide the actual axial clamping force you want (ie: the shit don't turn so easy so you think it's done too soon).

I really wish they made hollow studs for our cars.... that's the only way to get really close to a given clamping force. Hollow's are great.

Yes, the headbolts are reusable.

80lbs is high... don't go over manufacturer specs just becaust you think it'll be better... you'll break something.

Also, rebuilt of not, you don't know what shape the head was in... could have warped from inappropriate storage. Measure it with a machinist's straight edge (not just a metal ruler! ).

dang. how hard is it to chase threads yourself? and i want to make sure im doing this correctly. also i know the tsrm says 56lb for torque on the head and everyone says its too low. ive seen some do 70lb and then some do 90lb for arp. what do you recommend.

also i think im going to pull the engine out and put it on a stand. so i have a couple questions. how hard is it to drop in a fully assembled engine? would the wire harness be a problem. also i heard that cork oil pan gaskets are no good. whats the best way to seal this? im also going to be double checking all my seals and i think that my rear main seal might be leaking but should be fine.

im hoping that if all goes well i can swap out the tranny during this process.

thanks again guys, let me know if there is anything i should check that could be damaged from the engine.

[btwilson86]

Pulling the engine on these cars is fairly straightforward. You can leave it almost fully assembled if you pull the wiring harness with the engine. All you have to do is remove your glovebox, unplug the harness from the ECU, and push the wires and the grommet out through the firewall into the engine bay. Then just find the couple of connectors that go to body electronics, and you're good to go.

IMO, it's easiest to pull the transmission with the engine. Helps maintain the proper angle when removing it from the car, and then you don't have to deal with the PITA bolts at the top of the bellhousing.

And one last thing, remove your hood! First time I didn't think it through and halfway through the process I had to stop to get that thing out of the way

[cre]

Chasing the threads is easy. Just do it when you've got some energy and patience left. What you want is an "Intermediate" or "taper" type. I'll dig up the size when I have a moment. The only real trick is keeping the tap VERY well lubed and cleaning out the hole frequently (especially important with a block that hasn't had the threads chased in a long time). So, you take head off and clean out the bolt hole thoroughly, lube the tap with some lightweight motor oil, start threading the tap in (getting it started is the tricky part, DO NOT LET IT MISTHREAD!!!!!!!!!!!), then slowly and steadily thread the tap in half way or so. Now remove and clean the tap and finish threading it into the bolt hole. Remove the tap, clean it and the hole out thoroughly and thread the tap back into the hole and chase it the whole way to be sure everything is smooth. Remove the tap, clean out the hole and tap again and move on to the next.

When I say the manufacturer's specs I meant the manufacturer of the fastener... not the car. ARP specifies 75ft lbs for 7M head bolts and 90ft lbs for 7M head studs.

By the way, there is actually a difference between a "chase" and a "tap". A chase is generally a little undersized and doesn't cut the block material as much. These are intended to correct misshapen threads. Taps are intended for cutting new threads into a material. The difference with a cast iron block isn't a critical one, although I think with an aluminum block a tap in place of a chase would be a big no-no.

[cvbikeguy]

Originally Posted by btwilson86

Pulling the engine on these cars is fairly straightforward. You can leave it almost fully assembled if you pull the wiring harness with the engine. All you have to do is remove your glovebox, unplug the harness from the ECU, and push the wires and the grommet out through the firewall into the engine bay. Then just find the couple of connectors that go to body electronics, and you're good to go.

IMO, it's easiest to pull the transmission with the engine. Helps maintain the proper angle when removing it from the car, and then you don't have to deal with the PITA bolts at the top of the bellhousing.

And one last thing, remove your hood! First time I didn't think it through and halfway through the process I had to stop to get that thing out of the way

ok so maybe that will be a better option than getting it down to the block and then removing it. either way i will be taking the tranny out at the same time then swapping in the r154. and yea i cant imagine pulling the engine with the good still on.

Originally Posted by cre

Chasing the threads is easy. Just do it when you've got some energy and patience left. What you want is an "Intermediate" or "taper" type. I'll dig up the size when I have a moment. The only real trick is keeping the tap VERY well lubed and cleaning out the hole frequently (especially important with a block that hasn't had the threads chased in a long time). So, you take head off and clean out the bolt hole thoroughly, lube the tap with some lightweight motor oil, start threading the tap in (getting it started is the tricky part, DO NOT LET IT MISTHREAD!!!!!!!!!!!), then slowly and steadily thread the tap in half way or so. Now remove and clean the tap and finish threading it into the bolt hole. Remove the tap, clean it and the hole out thoroughly and thread the tap back into the hole and chase it the whole way to be sure everything is smooth. Remove the tap, clean out the hole and tap again and move on to the next.

When I say the manufacturer's specs I meant the manufacturer of the fastener... not the car. ARP specifies 75ft lbs for 7M head bolts and 90ft lbs for 7M head studs.

By the way, there is actually a difference between a "chase" and a "tap". A chase is generally a little undersized and doesn't cut the block material as much. These are intended to correct misshapen threads. Taps are intended for cutting new threads into a material. The difference with a cast iron block isn't a critical one, although I think with an aluminum block a tap in place of a chase would be a big no-no.

lol oh man. ive used a tap and dye before is this somewhat the same? and once i tap the holes i wont need bigger size bolts? and how much resistance should i be feeling when i do this? wow so many questions. where can i buy this and how long does it need to be? and should i apply rtv to my bolts when i install them? thanks for all the info. my patience has greatly improved from this car. im actually excited to hack at this more with the tranny coming in. i also want to upgrade the suspension like we talked about earlier with bushings, shocks and springs. ill also be prepping the interior.im working locally so transportation isnt a must anymore.

thanks again

[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.

[cre]

Originally Posted by cvbikeguy

lol oh man. ive used a tap and dye before is this somewhat the same? and once i tap the holes i wont need bigger size bolts?

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).

Originally Posted by cvbikeguy

wow so many questions. where can i buy this and how long does it need to be?

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.

Originally Posted by cvbikeguy

and should i apply rtv to my bolts when i install them?

Absolutely not!

[cre]

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

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