Printable Version of Topic

Posted by: malcolm2 Jul 19 2020, 03:15 PM

I have read thru books galore, watched Jake's video, etc..... I do not see anywhere that any sealant is used here. Not gonna use the head gaskets in the kit.

This is my 2nd type 4 engine and I don't remember what I did 7 years ago, much less last week.

So do the heads slide on "DRY"?

Thanks, Clark

Posted by: Krieger Jul 19 2020, 04:02 PM

No gaskets and dry.

Posted by: malcolm2 Jul 19 2020, 04:36 PM

I did find it in Tom Wilson's book. I don't like the way that book jumps from type 1 to type 4. I jump past important stuff. Oh well. Thanks for confirming.

Posted by: Bleyseng Jul 19 2020, 06:02 PM

Nowdays we lap the cylinders to the head using valve lapping compound. Testing the seal with Prussian Blue to verify that the seal is perfect.
Put a little compound on the cylinder lip to be used and with a back and forth motion, lap the bugger into the head. Clean everything off afterwards and apply a dap of PR on the lip and rotate it to the head to get a reading when you put if off. The PR should be continuous on the head surface.

Posted by: HAM Inc Jul 19 2020, 08:18 PM

Note to anyone using my heads.

Do not lap the jugs into them. We CNC machine our cylinder contact surfaces. They have a near mirror finish and ht's are even within .0001".

Lapping will roughen the surfaces and can only negatively impact the ht's.

If you have doubts about the flatness of your jugs, tape some 600 grit sandpaper to a pane of glass and spin the jug.

For sealant I recommend spraying a nice liberal coat of Permatex Copper Coat on the head's cylinder contact surfaces about 10 minutes before the heads are installed. Don't worry about overspray in the chambers or on the fins. It won't hurt a thing. I do like to mask the spark plug threads.

Posted by: porschetub Jul 19 2020, 11:13 PM

I use a little Hylamar blue under the barrel base shims as I don't think it can do any harm,its non-setting so is good in this area IMO.
If you are doing headgasket delete make sure your heads machined accordingly when flycut is done.
This is important stuff with a bus engine,good luck.

Posted by: malcolm2 Jul 20 2020, 09:06 AM

I have the sealant kit from Type4 store, so I put "whatever" they suggested under the barrels and on the shims.

Now I remember the copper spray from 7 years ago. HAM suggested that then. I still have the can, so I will apply that again.

THanks to all for chiming in.

Posted by: malcolm2 Jul 23 2020, 06:46 PM

Posted by: HAM Inc Jul 23 2020, 07:26 PM

Perfect!
That's exactly how you do it.

Posted by: cuddy_k Jul 23 2020, 08:06 PM

Noted! Can't wait to get to that step on my bumblebee.

Posted by: Superhawk996 Jul 24 2020, 07:08 AM

Thanks Len!

Same as Cuddy_K -- can't wait to put my T4 back together with your 2.0L heads.