Hi,

Read the threads here and PP BBS. I know I need to use Viton Seals, clean, clean, clean and deburr the head / lifter bores for a good seal.

I would like to use either Curil-T or one of the Loctite products (565 or 567 (the high temp version of 565).

Would either of these three products work?

The older threads stated to only use oil/grease - but the threads from 2004-Present appear to endorse using a sealant like the ones above.

Frank

NO sealant, no glue. The tubes move in their bores while the engine expands and contracts. Use only the Viton seals and either oil or a thin coating of grease.

light coat of fresh engine oil is all you'll need ...

Andy

A type IV engine expert used to recommend using permatex silicon thread sealant.

EDIT: make that teflon, not silicon!!!!!!

another TV expert here on the board will tell you that if you do, you *will* DIE ...

Andy

PS: care to elaborate who this type IV engine expert is?

"Used to", and he was wrong. A thin wipe of motor oil is ALL you need. Rubber seals are designed to seal directly against the metal. The Cap'n

The guys over at the ShopTalkForums talk about using liquid teflon pipe thread sealant on the pushrod tube seals. At least that's what I read.

Thats what I am talking about and the location of the forum should answer the MASSIVE question of who?

Silicon was a bad on my part.... meant to say teflon.

Sounds like motor oil is the concensus here, but I do recall a respected TIV engine builder recommending "loctite 565 flexible sealant."

I saw that as well. According to Loctite - 565 or 567 are interchangeable in this application.

Oil or grease? That is what I am using on my 912.

Perhaps the key is the cleaning and deburring - the prep. Regardless of what you use.

What is the harm in using 565 or 567? Will the tubes not be able to "float"? Causing leaks?

Thanks for everyone weighing in.

When installing, I just rub some "silicon" gel-like lubricant on them and they smoothly pop in. No sleanat, no adhesives... Fresh motor oil works good too.

the surface finish quality of the bore is very important for a moving bore seal o-ring application. Viton o-rings are soo nice. they are very resistant to abrasion and chemicals

I recently replaced the seals with Viton ones with a light coat of grease and I have no leaks since the replacement (approx 1500 miles)
Joe

I guess I miss out on all the fun. I have never used sealant on them. I wipe some oil on them and go on my way.

I think the key is: use new pushrod tubes



B

The stuff the massive guy uses is not really a sealant like normal sealants. You can get it in the plumbing dept at home depot. It is white teflon pipe dope, it comes in a small can with a brush applicator lid. You can cut it with a little paint thinner. It works really well, it lubes the seal and never hardens. Locktite makes a similar product but I don't know what the # is.

I went with the Teflon thread sealant on mine with the reasoning that it would not tear the seals during installation because it's sorta slippery, would not harden so it would flex with the temperature variations of a Type IV, and would assure a more positive seal than just oil and pressure.

I know that goes against the advice of some, but the logic worked for me and so far the seals have also. My engine has NO oil leaks - a first for me with a Type IV or Type 1 - and something I'd sworn was possible using modern sealants if one just worked at it.

Perhaps a question to those who have used 565/teflon paste -

Have you ever had it leak and if so - how was replacing the o-rings? Was it difficult to remove the tube/clean?

Thanks!

There are a lot of opinions on this...

I either use engine oil to install the tubes or I prefer the use of Loctite 565. The 565 is flexible and allows expansion and contraction with a seal thats incredible and won't leak a drop for the entire life of the engine...

I only use the engine oil on race engines that will be coming back apart regularly. The teflon sealant has helped me earn a rep for leak free engines and I recommend it to everyone.

I used the 565 on my 912E engine 97000 miles ago and the pushrod tubes and entire engine are so dry that the pushrod tubes are rusting!

The big issue is the burrs and irregularities that are found in the head and case bores- they cut seals terriably upon install and cause leaks. The nice thing about the teflon is the fact that it is flexible and also is very slippery to aid installs without the chance of cutting the seal.

Another thing I do is just use the teflon on the head side of the tubes, the end thats most prone to leaks. The case side hardly ever leaks and if oil is only used to install that end of the tube the expansion factor is non existant as the tube moves in the case bore more than enough...

If using 565 is wrong I have built 700+ engines the wrong way, makes you wonder why they didn't leak!

You can use engine oil or 565, do what you want! I found that the teflon worked well by trial and error experimentation... Because I HATE oil leaks!

Hi Jake,

Thanks for your detailed reply.

According to Loctite, 567 is the higher temp version of 565. I spoke with a tech support person yesterday.

The local Loctite distributor has both, but the 565 is in a larger tube (8 oz) while the 567 is in a 50ml (2+oz) tube.

Do you see any issues with the 567?

Regards,

Frank

If you use 'silicon' on any seal I think you will be in trouble; remember that silicon is the crystalline element used to make computer chips.

Silicone however is probably something you were thinking of. Nice and soft when used correctly. But not for use within engines.

For pushrod tubes on the /4 or oil return tubes on the /6 I recall that Dow Corning 111 has been highly recommemended as well. Still. I would strongly advise taking Jake's advice.

The 567 sets up too hard.. been there and done that!
I use 14 sealanst to build a single engine- I have tried most everything on the planet for sealants! The Loctite rep stops by here once a week and I have actually done some R&D for them..

I'd like to add something to my post...

I generally run synthetic oils in my engines, the differences with synthetics and leaks Vs dino oils with the TIV are huge. Using the 565 keeps tubes dry even with synthetic, with proper preparation and installation....

A big contributor to pushrod tube leaks is also excess crankcase pressure. If the case or valve covers are over pressurized the oil is FORCED past any seal or gasket- the 565 withstands this pressure even when extreme.. Never understimate the benefits of a proper crankcase breather system.