 
     |
| Long Block swap, which bolts need locktight, sealant, torque specs? (Page 1/1) |
|
Filben
|
MAR 04, 04:15 PM
|
|
|
I am doing a 3.4 swap on an 86 V6 4 speed, I want to know which bolts need thread sealant, which need locktite, any that need torqued specifically. Cheers!
|
|
|
|
cartercarbaficionado
|
MAR 04, 07:05 PM
|
|
| quote | Originally posted by Filben:
I am doing a 3.4 swap on an 86 V6 4 speed, I want to know which bolts need thread sealant, which need locktite, any that need torqued specifically. Cheers! |
|
i dont remember but everything is the same as a 2.8 stock engine. so use that or the build threads for 3.4s
|
|
|
|
82-T/A [At Work]
|
MAR 05, 07:51 AM
|
|
I'd recommend getting the Factory Service Manual if you can. There's a link that someone has where you can download it for free, or you can buy it from http://www.TheMotorBookStore.com
You absolutely / definitely want to get the torque specifications right on all the bolts. TRUST me on that. Not torquing things down will cause all kinds of problems.
Off the top of my head, for the V6 though...
You want to use red locktite on things like the flywheel bolts. But I think you need sealant on a couple of the cyl head bolts... I cannot remember. I just went through this with my daughter's car... and the factory service manual had this torque specification sheet on it for her 4 cyl:
DO NOT USE THIS...
I want to be explicitly clear, this is literally ONLY for the L4 / Iron Duke. I'm only including it so that you can see what you can expect if you get the factory service manual. If you were to follow these torque specifications, you would strip the threads in the engine block for the cyl heads, and cause other damage... so do not refer to this. But... if you get the factory service manual, it has a whole spec sheet like this. Make sure you get a good torque wrench, and don't be like me... when I first tried to do this many years ago, I confused newton meters with foot-pounds, and I broke a lot of stuff... so make sure you are careful with which setting you choose, Nm vs ft-lbs. You probably already know that, but just wanted to say it in case you didn't... because man... lot of tears from my screw-ups over the last couple of decades, haha...[This message has been edited by 82-T/A [At Work] (edited 03-05-2025).]
|
|
|
|
1985 Fiero GT
|
MAR 05, 08:10 AM
|
|
| quote | Originally posted by 82-T/A [At Work]:
Off the top of my head, for the V6 though...
You want to use red locktite on things like the flywheel bolts. But I think you need sealant on a couple of the cyl head bolts... I cannot remember. I just went through this with my daughter's car... and the factory service manual had this torque specification sheet on it for her 4 cyl:
DO NOT USE THIS...
I want to be explicitly clear, this is literally ONLY for the L4 / Iron Duke. I'm only including it so that you can see what you can expect if you get the factory service manual. If you were to follow these torque specifications, you would strip the threads in the engine block for the cyl heads, and cause other damage... so do not refer to this. But... if you get the factory service manual, it has a whole spec sheet like this. Make sure you get a good torque wrench, and don't be like me... when I first tried to do this many years ago, I confused newton meters with foot-pounds, and I broke a lot of stuff... so make sure you are careful with which setting you choose, Nm vs ft-lbs. You probably already know that, but just wanted to say it in case you didn't... because man... lot of tears from my screw-ups over the last couple of decades, haha...
|
|
For the Fiero 2.8, you use sealant on all head bolts, I don't think they all need it but you use it anyway for torque equalization, for other 60* v6, some need it done don't, some not at all, my 3400 had all the head bolt threads sealed off, but you still use the Fiero sealant and torque. For the head bolts specifically, it probably wasn't your fault, many of the aftermarket manuals get the number messed up between ft/lb and n/m, saying 90 ft/lb when the official Fiero service manual says 66 or so (90 ish n/m) another thing to check is the diameter of the new head bolts, it seems there's an issue with some new bolts being slightly smaller diameter than the originals, that and people torquing to 90ft/lb makes it guaranteed to strip the block. I bought new felpro head bolts, and threading them in by hand felt literally loose, I could wiggle the heads back and forth a little bit fully threaded in, and visually (no precise measuring tools) they appeared slightly thinner. So I've reused my original gm head bolts (they are not torque to yield) 2 times now, once on my 2.8 and once on my 3400 block, torqued to 66 ft/lb, in steps of 10-15 ft/lb.
|
|
|
|
82-T/A [At Work]
|
MAR 05, 08:56 AM
|
|
| quote | Originally posted by 1985 Fiero GT:
For the Fiero 2.8, you use sealant on all head bolts, I don't think they all need it but you use it anyway for torque equalization, for other 60* v6, some need it done don't, some not at all, my 3400 had all the head bolt threads sealed off, but you still use the Fiero sealant and torque. For the head bolts specifically, it probably wasn't your fault, many of the aftermarket manuals get the number messed up between ft/lb and n/m, saying 90 ft/lb when the official Fiero service manual says 66 or so (90 ish n/m) another thing to check is the diameter of the new head bolts, it seems there's an issue with some new bolts being slightly smaller diameter than the originals, that and people torquing to 90ft/lb makes it guaranteed to strip the block. I bought new felpro head bolts, and threading them in by hand felt literally loose, I could wiggle the heads back and forth a little bit fully threaded in, and visually (no precise measuring tools) they appeared slightly thinner. So I've reused my original gm head bolts (they are not torque to yield) 2 times now, once on my 2.8 and once on my 3400 block, torqued to 66 ft/lb, in steps of 10-15 ft/lb. |
|
Ugh... I am not looking forward to that... I wonder if there's a really GOOD set of aftermarket cyl head bolts I can buy, just so I could know they aren't crap and not TTY.
I have a spare V6 that's all original, sitting on a stand... you're saying I can take those originals off and use them in my 3.4 that I'm building up? And you torqued them to 66 ft-lbs?
It was... probably almost 2 decades ago when I stripped the threads in the V6 block. I ended up having to take it to a local shop who helicoiled it and put in a new bolt (or maybe re-used the other one). That's the 3.1 as it sits now in my 87 Fiero. But it wiped a couple of cam lobes after a few thousand miles... so it's just kind of sitting there. It runs fine, just has very little power above 4,000 rpms at all. I opted to not even bother with it... which is why I bought the 3.4 block.
|
|
|
|
Filben
|
MAR 05, 10:16 AM
|
|
| quote | Originally posted by 1985 Fiero GT:
For the Fiero 2.8, you use sealant on all head bolts, I don't think they all need it but you use it anyway for torque equalization, for other 60* v6, some need it done don't, some not at all, my 3400 had all the head bolt threads sealed off, but you still use the Fiero sealant and torque. For the head bolts specifically, it probably wasn't your fault, many of the aftermarket manuals get the number messed up between ft/lb and n/m, saying 90 ft/lb when the official Fiero service manual says 66 or so (90 ish n/m) another thing to check is the diameter of the new head bolts, it seems there's an issue with some new bolts being slightly smaller diameter than the originals, that and people torquing to 90ft/lb makes it guaranteed to strip the block. I bought new felpro head bolts, and threading them in by hand felt literally loose, I could wiggle the heads back and forth a little bit fully threaded in, and visually (no precise measuring tools) they appeared slightly thinner. So I've reused my original gm head bolts (they are not torque to yield) 2 times now, once on my 2.8 and once on my 3400 block, torqued to 66 ft/lb, in steps of 10-15 ft/lb. |
|
I am not doing the heads, I really just want to know about the lower intake, timing cover, the water pump, the accessory brackets. I need to know which get sealant, locktite, and torque specs. I tried to find a guide, or something but I found nothing. I figured there would be something in the HowTo section here but there isn't.
|
|
|
|
1985 Fiero GT
|
MAR 05, 11:06 AM
|
|
| quote | Originally posted by 82-T/A [At Work]:
Ugh... I am not looking forward to that... I wonder if there's a really GOOD set of aftermarket cyl head bolts I can buy, just so I could know they aren't crap and not TTY.
I have a spare V6 that's all original, sitting on a stand... you're saying I can take those originals off and use them in my 3.4 that I'm building up? And you torqued them to 66 ft-lbs?
It was... probably almost 2 decades ago when I stripped the threads in the V6 block. I ended up having to take it to a local shop who helicoiled it and put in a new bolt (or maybe re-used the other one). That's the 3.1 as it sits now in my 87 Fiero. But it wiped a couple of cam lobes after a few thousand miles... so it's just kind of sitting there. It runs fine, just has very little power above 4,000 rpms at all. I opted to not even bother with it... which is why I bought the 3.4 block. |
|
Yeah, you can, and yes I did, I think that was the factory spec, you have more budget and tools, so in your shoes, I would buy a few different ones, get real measurements on diameter and compare looseness, I'm sure arp has something that would work, and people like those, but as per the service manual, the head bolts are reusable and not TTY.
|
|
|
|
1985 Fiero GT
|
MAR 05, 11:08 AM
|
|
| quote | Originally posted by Filben:
I am not doing the heads, I really just want to know about the lower intake, timing cover, the water pump, the accessory brackets. I need to know which get sealant, locktite, and torque specs. I tried to find a guide, or something but I found nothing. I figured there would be something in the HowTo section here but there isn't. |
|
I don't know if specific guides for everything, but the factory service manual clearly tells you everything you need to know about that, torque sequences, torque specs, everything. It is available online somewhere, but it isn't bad to get a physical one to have on hand.
|
|
|
|
Raydar
|
MAR 05, 11:11 AM
|
|
|
|
|
Filben
|
MAR 05, 02:35 PM
|
|
Thank you. I was having trouble finding something like this.
|
|
|
|