Author Topic: MLS head gasket with stock cylinder studs  (Read 540 times)

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Offline Pbeattie89

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MLS head gasket with stock cylinder studs
« on: March 21, 2024, 05:37:47 AM »
Has anyone had luck using a mls gasket with stock studs? Stock studs are torqued to 13.7-15.2 ft/lbs, but PeWe mentioned that the mls gaskets need a higher torque to crush and seal, I think he mentioned around 22 ft/lb. I am leaning towards just buying some studs, but I figured I would get a few opinions first.

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Offline PeWe

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Re: MLS head gasket with stock cylinder studs
« Reply #1 on: March 21, 2024, 11:16:38 AM »
I tighten stock studs with ca 20 ft lbs.
20.65 with 836 (28Nm)
Again the day after. If compressed much, next day too.

MLS does not compress until day after. But I check anyway.

Stock studs are more flexible than heavy duty studs.
Fiber gasket will probably handle that better than MLS. Just a feeling, no hard facts.

Ask Mike Rieck (forum member MRieck) about MLS and stock studs and if he also recommend heavy duty studs for MLS head gasket.  (Stock engines)

He has tightened a great number of heads on different engines.

A harder pounding engine with higher compression and bigger bores sure need the more rigid hd studs.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline HondaMan

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Re: MLS head gasket with stock cylinder studs
« Reply #2 on: March 21, 2024, 08:50:14 PM »
Like PeWe, I've long used a little more torque, and on the subsequent day: caveat: I seldom use the MLS gaskets, though.

Using regular head gasket:
On the 'first pass' I go down to the max 15.2 ft-lbs/182 in-lbs, then the next day back off the nuts 1/2 turn (in reverse torque sequence) and start again at #1. The nuts always go down further on the 2nd run.

With HD studs, the maker of those studs usually provides their max torque value.
« Last Edit: March 21, 2024, 08:52:08 PM by HondaMan »
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline PeWe

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Re: MLS head gasket with stock cylinder studs
« Reply #3 on: March 21, 2024, 11:04:38 PM »
Both APE and Kibblewhite spec max 22.5 ft lb.
The accuracy of my wrench +/- 4%. So I see 96% of 22.5 as max, 21.6 ft lb, 29.3 Nm with my wrench.

Important to have a correct torque wrench and use it correctly. A clicking wrench need an even slow stroke until it click.
If I reach an obstacle and have to grip again from a better angle and it will click direct. I'll redo, loosen a little so it will click while nut or bolt is moving.

A snappy move of a torque wrench can end up in a huge error.
One wrench seller visiting my job showed how to do this correctly and incorrectly.
  +20-25% too much by tighten a bolt by a quick snappy movement.
That time, 1990,  90-120Nm bolts if I remember correctly.

I snapped one HD stud due to the torque wrench I had borrowed from my job's lab where they had off service wrenches.

I had to tighten the head nuts 36Nm (26.55 ft lb) to get them moving further with a new torque wrench. I tested a few head nuts to be sure.
I had tightened them 28Nm (20.65ft lb) with the bad wrench.

Time for me to order own torque  wrenches which I have used a lot since then. 
German brand Hazet that did not cost much more than the cheap ones 2014.
5120-2CT 10-60Nm 1/2".

Later model 5120-3CT has 3% tolerance and still OK price.

EDIT:
Threads + under nut or bolt head lightly oiled. Dry will cause friction and  lower clamping force .
There are charts with torque and different lubricants.

Oil vs  Molykote 1000 with less friction ending up in higher clamping force at same tightening force used with the wrench.

Our head nuts, lightly oiled.
Dry will not work well when tightening with torque wrench.
Test and feel it ;D
« Last Edit: March 22, 2024, 01:51:17 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline Pbeattie89

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Re: MLS head gasket with stock cylinder studs
« Reply #4 on: March 22, 2024, 12:16:17 PM »
I tighten stock studs with ca 20 ft lbs.
20.65 with 836 (28Nm)
Again the day after. If compressed much, next day too.

MLS does not compress until day after. But I check anyway.

Stock studs are more flexible than heavy duty studs.
Fiber gasket will probably handle that better than MLS. Just a feeling, no hard facts.

Ask Mike Rieck (forum member MRieck) about MLS and stock studs and if he also recommend heavy duty studs for MLS head gasket.  (Stock engines)

He has tightened a great number of heads on different engines.

A harder pounding engine with higher compression and bigger bores sure need the more rigid hd studs.
I've just heard back from Mike, and he recommends the HD studs while using the MLS gasket even on the stock motor. The stock studs just dont clamp down hard enough to get a proper crush and seal on the MLS. He also recommended 22ft/lb.

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Offline Pbeattie89

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Re: MLS head gasket with stock cylinder studs
« Reply #5 on: March 22, 2024, 02:13:20 PM »
Here is a question for you guys. Is there any merit to getting uprated nuts to go with the stud kits? Can the stock nuts handle 22ft/lb?

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Offline HondaMan

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Re: MLS head gasket with stock cylinder studs
« Reply #6 on: March 22, 2024, 06:45:57 PM »
I've never used anything other than the OEM nuts, even with HD studs on (racing) engines with as much as 25 ft-lbs torque on them.
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline PeWe

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Re: MLS head gasket with stock cylinder studs
« Reply #7 on: March 23, 2024, 12:27:00 AM »
I use Honda nuts. Last assembly ca 29.45Nm. (21.7 ft lb)
Honda nuts for case studs too I tightened 25Nm.

I reused an MLS that had been torqued 29Nm before.
It had been used only 1200km.

I have another used gasket of same size, used 5800km, look good like it can be reused, tighten it harder than before. This is the good thing with MLS head gaskets and RCS base gaskets.

70mm bore, 0.03" thick MLS from Dynoman that had sale, $29.95 each. I should have bought more than 3 ;)


Over 8000km done and no leaks.
It had weaped oil around oil filter. Replaced the o-ring around the bolt with a thicker viton o-ring 15x2.5mm.

I think the gasket crushed at around ca 27Nm (ca 20 ft lb).
https://www.unitconverters.net/energy/ft-lb-to-nm.htm

The nuts suddenly move easier when tighten.
Possible to hear gasket give after too.

That engine has Rubber Coated Steel base gasket and have been reused several times. Thinner model.
Last time with a very thin layer of high temp RTV on both sides, cured for an hour or two before using it. It was a minor oil weep before.

Here photos of that assembly late August 2022.
The reused MLS, 2 knock pins in outer front corners not yet there, comment in Swedish.





Note!
Do not forget that MLS gasket need a flat and smooth surface.
No scratches that fiber gasket has no problems with.
« Last Edit: March 23, 2024, 04:46:59 AM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline HondaMan

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  • Posts: 13,861
  • ...not my choice, I was nicknamed...
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Re: MLS head gasket with stock cylinder studs
« Reply #8 on: March 24, 2024, 08:01:46 PM »

That engine has Rubber Coated Steel base gasket and have been reused several times. Thinner model.
Last time with a very thin layer of high temp RTV on both sides, cured for an hour or two before using it. It was a minor oil weep before.


PeWe: where did that steel gasket come from, and do they make one for standard-size 750 (or maybe...500/550) bores?

I found those types of gaskets to be invincible in my older Ford engines. I drove the last one 450k+ miles with that head gasket, even after having to remove it and re-use it during the build (because the machine shop screwed up and installed the rear cam bearing wrong, cutting off all top-end oiling, grr...never used THAT shop again...).
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: https://www.lulu.com/search?adult_audience_rating=00&page=1&pageSize=10&q=my+cb750+book

Link to website: www.SOHC4shop.com

Offline PeWe

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  • Posts: 15,581
  • Bike almost back to the 70's 2015
Re: MLS head gasket with stock cylinder studs
« Reply #9 on: March 24, 2024, 11:20:46 PM »

That engine has Rubber Coated Steel base gasket and have been reused several times. Thinner model.
Last time with a very thin layer of high temp RTV on both sides, cured for an hour or two before using it. It was a minor oil weep before.


PeWe: where did that steel gasket come from, and do they make one for standard-size 750 (or maybe...500/550) bores?

I found those types of gaskets to be invincible in my older Ford engines. I drove the last one 450k+ miles with that head gasket, even after having to remove it and re-use it during the build (because the machine shop screwed up and installed the rear cam bearing wrong, cutting off all top-end oiling, grr...never used THAT shop again...).
I ordered my gaskets from Dynoman.
I see they have RCS base gaskets for CB500/550/650 too.

Scroll down
https://www.dynoman.net/engine/gaskets-cometic.html#60mm-cb550
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967