Cylinder head bolts - replace during rebuild?

[Dave_EH]

Hi,

I'm wondering if it is best practice to use new head bols when building a new motor?

In the past I have just used the old bolts.  I guess these are getting a bit long in the tooth now, and there is potential for a bit of thread stretch.

Aftermarket sets for red motor are available at about $50 for a set of 14.  Double that for ARP.

I also used to use the Holden stud sealer on the bolts when assembling.  Is this product still available, and is it necessary?

Cheers
Dave

[fe350chev]

I would not tap the holes but use a thread chaser. If you don't know the engine and how many times the bolts have been torqued up then I would replace them if it was me. Also, don't forget when torquing them up to lightly oil the underside of the bolt flange so there's no binding bare metal and it doesn't hurt to use gm or permatex red on the bolt threads on all of the bolts if your not sure which ones it's crucial.

[fe350chev]

http://m.ebay.com.au/itm/HEAD-STUD-SEALANT-GM-3835215-GENUINE-HOLDEN-BOLT-GASKET-SEALANT-AC-DELCO-250ML-/251463773911

[fe350chev]

Oh forgot. If you have had the valves out, don't forget to go the max gap on assembly and some ppl bring engine to operating temp and then recheck the torque. Allow for valves to bed in and readjust as per manual. Gaskets are marked which side up these days. Make sure the valve seats are modified for unleaded and the guides are ok.

[Dave_EH]

Thanks.

I'll go for new bolts this time.  I'll be using the same head, as it only has a few thousand miles on it.

It's been suggested to use moly grease instead of the stud sealant in order to get a more accurate torque setting on the head?

Dave

[ardiesse]

Dave,

The red motor head bolt holes are drilled through to the water jackets, and the main purpose of the sealant 3835215 is to stop leakage of coolant water up the threads and rusting things up.  When installing a red motor head I dip the threaded part of the bolt into the sealant, let the excess run off, and then put the bolt straight into the hole.

3835215 stinks of solvents, it skins over really fast, but it works a treat . . .

Rob

[fe350chev]

Is it a red or a grey just out of interest?

[Fraze]

Is It really necessary to use a sealant on the head bolts of a grey motor? Seems to me if you have to re-torque the head after a few hundred miles you will disturb the sealant and negate or reduce its effectiveness anyway! let's hear please, Frazer

[hsv-001]

Wow!, Ive always just check and clean up the threads in the block [blown them out with the compressor] and on the bolts, used a permaseal type head gasket , some gasket goo or permatex on the thread ,maybe a little oil under the bolt heads and pulled them down in order ,usually till my elbow hurts [rarely even use a torque wrench these days] . I may be wrong but I don't remember the head bolts needing the sealant until the introduction of the later reds ,the bridged rocker reds 202,173and the 138 .Cheers . Haydn 

[ardiesse]

Haydn,

All the red motors require stud sealant on the head bolt threads, not just the post-'71 versions.

Rob

[fe350chev]

I didn't know which motor he was talking about so I would usually give advice to anyone building any engine to put a bit on the bolts if they aren't totally sure themselves. It only takes a few seconds and it cannot cause any issues if you put some on unnecessarily. We were taught this in trade school but I must admit, I was trained as a diesel mechanic and many bores are replaceable. Not sure whether any of you have used thread tape but I'm.pretty sure it's designed to still be effective after even a 3 stage torque up in a similar fashion to normal dry tape. With so many engines that would randomly come in, u don't have time either to research everything but easier now with the internet.

[Dave_EH]

Thanks,

It is a RED motor.

I have always used the thread sealant, but I have now lost the tin.  It's $60 odd dollars and you only use about 1% of the tin, so I just wanted to confirm if something like Loctite 3J or the equivalent Permatex product would be suitable?

[hsv-001]

Rob I have double checked my workshop manuals and can't find where you get the information regarding sealing head bolts. I just checked FX-HK and found no reference to sealing the bolts and don't remember doing it back in the day[Late 60's early 70's] .However as I didn't find my HQ manual I grabbed my Torana starfire manual and as I thought it does explain the use of sealant on the head bolts . As the starfire is a shortened[4 cylinder]  bridged rocker red [173]I would check your information . But I guess many of the people on this forum would be unsure of the history of their engines with regard to block and head work as well as corrosion and rethreading of bolt holes etc. and would seal to be on the safe side . I run an early worked head on a later block so I seal the headbolts . If you can find where this comes from I would be interested as you would think it would be in the early red motor manuals. Cheers.Haydn

[fe350chev]

http://www.glwholesalers.com.au/567-mx-tmp-pipslt-50ml-tbcg

[fe350chev]

I like the smell of the white stuff lol. You can use that.

[fe350chev]

These look very nice in blue.

[ardiesse]

@haydn,

My info about thread-sealing the head bolts on red motors comes from the EH-onwards Holden workshop manuals.  I don't think the aftermarket manuals like the Gregorys or Scientific Publications mention the need for thread sealant.

In every red motor I've rebuilt, I ran a 7/16 UNC tap down the head bolt holes to clean the threads, and in 13 of the 14 head bolt holes in the block I was able to run the tap right through into the water jacket.

Rob

[Harv]

Is It really necessary to use a sealant on the head bolts of a grey motor? Seems to me if you have to re-torque the head after a few hundred miles you will disturb the sealant and negate or reduce its effectiveness anyway! let's hear please, Frazer

G'day Frazer,

Generally, no sealant on the grey motor head bolts. Be careful about what cylinder head gasket you buy though - some of the modern ones only get torqued up once, and then are not disturbed (referred to as "monotorque"). Just as good as a retorqueable one, just a different process.

Cheers,
Harv

[Professor Grey]

Hi Guys,
I have many different (Gregorys, Ellerys, SP, etc) workshop manuals for red motors of varying vintages, and ALL of them say to apply non-setting sealant to head studs.
Logic dictates this is because the red head stud holes penetrate the water jacket, and it is possible that water could travel up the thread.
I have Ellerys and GMH manuals for Greys, and they have only light oil applied to the studs.
Cheers,
Prof.

[fe350chev]

Shouldn't really tap and dye them. Use thread chaser instead.