Hemi Motor TRQ Specs

[dchapma1957]

OK folks. it is done. Start to finish, 8 hours including the oil change, cleaning up and putting away tools and a test drive.

New cam bolt, I flushed the cam bolt hole threads with brake cleaner thoroughly, then blew it out with compressed air, twice. It was clean! Applied a small amount of Blue thread locker and torqed that sucker to 90!

I also applied a thin coating of gasket maker to the vibration damper hub, used the old bolt to run it on, then removed the old bolt and put in a new bolt and torqued it to 130.

Everything is all back together. One thing I could not tighten 100% is the bolt on that funny looking, ground bar? that runs from the left head to the TC cover. Bolt in the head is tight, bolt in the timing cover isw snug. The whole thing was back together before I realized it was never fully tightened. I think it will be fine.

So ends the saga of the cam bolt torque. I never want to mention it again!

 

[Wild one]

OK folks. it is done. Start to finish, 8 hours including the oil change, cleaning up and putting away tools and a test drive.

New cam bolt, I flushed the cam bolt hole threads with brake cleaner thoroughly, then blew it out with compressed air, twice. It was clean! Applied a small amount of Blue thread locker and torqed that sucker to 90!

I also applied a thin coating of gasket maker to the vibration damper hub, used the old bolt to run it on, then removed the old bolt and put in a new bolt and torqued it to 130.

Everything is all back together. One thing I could not tighten 100% is the bolt on that funny looking, ground bar? that runs from the left head to the TC cover. Bolt in the head is tight, bolt in the timing cover isw snug. The whole thing was back together before I realized it was never fully tightened. I think it will be fine.

So ends the saga of the cam bolt torque. I never want to mention it again!

Good show now you'll sleep better,lol. I'm not placing this bar you're referring to,have you got a pic of it,the only bar i remember is the one off the alternator.

 

[dchapma1957]

Good show now you'll sleep better,lol. I'm not placing this bar you're referring to,have you got a pic of it,the only bar i remember is the one off the alternator.

I don't have a picture but it sits right under the alternator and is bolted to the timing chain cover and the left head. It's funny looking piece, about 1/4" in diameter with a bend in it to account for height differences. It is tight on the head and finger tight on the TC cover - I just can't get to it without taking the alternator off and frankly, I'm all done. I'm pushing 68 and a full day of wrenching takes a toll on me so I am calling it done.

 

[dchapma1957]

Number 3 in the picture.

 

[Wild one]

Number 3 in the picture.
View attachment 554124

Gotcha now that i see the pic.I don't think it being just snug will be an issue,i took that alternator stabilizer bar off the wifes Challenger when i put long tubes on it,as it was in the way of installing the long tubes,and was virtually impossible to re-install after they were in place.

 

[Barr2255]

I don't have a picture but it sits right under the alternator and is bolted to the timing chain cover and the left head. It's funny looking piece, about 1/4" in diameter with a bend in it to account for height differences. It is tight on the head and finger tight on the TC cover - I just can't get to it without taking the alternator off and frankly, I'm all done. I'm pushing 68 and a full day of wrenching takes a toll on me so I am calling it done.

Ahh the bone/random thingy majig. That ties the head to the timing cover. Ehh yeah snug is good. It isn’t going anywhere.

But I say that with my 63’ lb torqued cam phaser as well! Love you @wildone

 

[Wild one]

Ahh the bone/random thingy majig. That ties the head to the timing cover. Ehh yeah snug is good. It isn’t going anywhere.

But I say that with my 63’ lb torqued cam phaser as well! Love you @wildone

No problem Chris,i agree i don't think it's really a crucial piece,so snug is probably good,lol

 

[dchapma1957]

Snug means like as tight ass I could get it with my fingers. Frankly, I don't even see what it is for. There are 10 bolts holding the timing chain cover on. Maybe in a week or 2 I will pop the alternator and tighten it up but for now, now mor wrenching for awhile!

 

[Barr2255]

Snug means like as tight ass I could get it with my fingers. Frankly, I don't even see what it is for. There are 10 bolts holding the timing chain cover on. Maybe in a week or 2 I will pop the alternator and tighten it up but for now, now mor wrenching for awhile!

Lol well your an experienced wrencher and my guess is your finger tight is stronger than most.

With that said I’m not sure the true thought process of the engineers in this regard. Maybe it’s there to dilute frequency vibration.? Yeah that… I’m going with vibration dampener lol

 

[Ken226]

I was bored and reading some old threads when this one spurred me to look in my Dodge and Ram factory service manuals for my Ram and my wife's Durango. Both have the 5.7 Hemi

The 2011 Durango:



And my 2013 Ram 5.7:



I wonder why they are different.

 

[Wild one]

I was bored and reading some old threads when this one spurred me to look in my Dodge and Ram factory service manuals for my Ram and my wife's Durango. Both have the 5.7 Hemi

The 2011 Durango:
View attachment 557672


And my 2013 Ram 5.7:

View attachment 557673

I wonder why they are different.

The cars call for 90 lb-ft,and they all use the same bolt. The guys who have issues with shearing the cam pin,are the guys who usually aren't using the 90 lb-ft spec.

 

[Ken226]

The cars call for 90 lb-ft,and they all use the same bolt. The guys who have issues with shearing the cam pin,are the guys who usually aren't using the 90 lb-ft spec.

I agree that 90 sounds better and if I end up doing this job, that's what I will use. But the official, factory service manuals from Chrysler are wrong? Or perhaps mistaken?

 

[Wild one]

I agree that 90 sounds better and if I end up doing this job, that's what I will use. But the official, factory service manuals from Chrysler are wrong? Or perhaps mistaken?

If you look up the bolt it's rated to well above 90 lb-ft Ken.The majority of after market cam outfits all spec 90 lb-ft.
Somethings fishy with the factory spec's as there's 3 differant torque specs for the same bolt and cam phazor,and i'd rather err on the safe side and use the higher torque spec,if the bolts not tight enough,it'll allow the phazor to spin and shear the cam pin,then things get really expensive in a hurry,as the hemi is an interferance engine

 

[Ken226]

If you look up the bolt it's rated to well above 90 lb-ft Ken.The majority of after market cam outfits all spec 90 lb-ft.
Somethings fishy with the factory spec's as there's 3 differant torque specs for the same bolt and cam phazor,and i'd rather err on the safe side and use the higher torque spec,if the bolts not tight enough,it'll allow the phazor to spin and shear the cam pin,then things get really expensive in a hurry,as the hemi is an interferance engine

Yea, i agree 100%. Looking up the torque spec for that bolt (m12x1.75 10.9), and every torque chart from Engineers Edge to Fastener Mart all show the same thing. A M12x1.75 grade 10.9 bolt calls for about 92 fl lbs.

Here is an example from "Fastener Mart", but they are pretty much all the same:



Also, GM used to use the same bolt size/grade on their turbo diesel engines and their manuals used to call for 73 ft lbs, but suddenly without explanation, one day they changed the spec to 125 NM (92 ft lbs), on the same bolt part#.

GM Upping torque on M12x1.75 class 10.9 bolt?

The cam bolt in GM 6.5 Turbo Diesel engines is an M12x1.75 grade 10.9. GM changed the torque spec from 65 Lbf-ft to 125 lbf-ft without changing the bolt. All torque charts I read show approximately 73 Lbf-ft as being the maximum torque for this bolt. I simply can't find justification anywhere...

www.eng-tips.com

It sounds like someone at the factory put the torque spec for a grade 8.8 bolt in the manual.

 

[Wild one]

Yea, i agree 100%. Looking up the torque spec for that bolt (m12x1.75 10.9), and every torque chart from Engineers Edge to Fastener Mart all show the same thing. A M12x1.75 grade 10.9 bolt calls for about 92 fl lbs.

Here is an example from "Fastener Mart", but they are pretty much all the same:

View attachment 557681

Also, GM used to use the same bolt size/grade on their turbo diesel engines and their manuals used to call for 73 ft lbs, but suddenly without explanation, one day they changed the spec to 125 ft lbs, on the same bolt part#.

GM Upping torque on M12x1.75 class 10.9 bolt?

The cam bolt in GM 6.5 Turbo Diesel engines is an M12x1.75 grade 10.9. GM changed the torque spec from 65 Lbf-ft to 125 lbf-ft without changing the bolt. All torque charts I read show approximately 73 Lbf-ft as being the maximum torque for this bolt. I simply can't find justification anywhere...

www.eng-tips.com

It sounds like someone at the factory put the torque spec for a grade 8.8 bolt in the manual.

Depends on where you look to,as i've found torque specs for the bolt at 95 lb-ft and 98 lb-ft,and one that i ruled out that claimed a torque spec of 125 lb-ft,i didn't give that spec much credit though

 

[Ken226]

Depends on where you look to,as i've found torque specs for the bolt at 95 lb-ft and 98 lb-ft,and one that i ruled out that claimed a torque spec of 125 lb-ft,i didn't give that spec much credit,but if GM is calling for 125 lb-ft,maybe it has some merit

I think the guy on that Engineering forum mixed up NM with Ft Lbs. Later in the thread, post# 6, a former GM materials science engineer, corrected him that the spec was 125Nm, 92 ft lbs.

 

[Hagar1]

it' a good thing I found your post on rocker arm rail torque. We almost torqued them to 105 ft lbs not inches. Why would Haynes put inches in the manual when all torque wrenches are in feet? Thanks

Inch/lb torque wrenches are used in plenty of delicate assemblies. My tool box has 3 torque wrenches... Inch/ lb, ad 2 ft/lb wrenches. One goes to 200 and the other goes to 75. Always used the in/lb for valve bodies in automatics.