way off topic...but do u know?(h/d related)

vinsanity69 · Post by **vinsanity69** » Sun Sep 09, 2007 9:46 pm

In a nut shell....

My shovel keeps blowing the rear head gasket,in different spots.Around the oil return hole or the cylinder head bolt on the intake side.
The head and cylinder are flat,I put them on a surface plate and gauged them.The factory gasket went.A teflon gasket blew and a copper gasket leaks.Obviously I went back to the builder and of course he re-nigged on his word,so this is in my lap and I need help.I want to ride......
:bfg
I have relaced 4 head gaskets in two days and only been 25 miles......
Something is way wrong here....I have called every buddy I have that knows these engines and no one has come up with a clue.

The torque is right and in the right sequence,no holes or threads are damaged and it all lines up??

I know this is not a yami..but I'll ride anything that has 2 wheels and goes fast...
Any thoughts or suggestions are greatly appriciated.....

silver · Post by **silver** » Sun Sep 09, 2007 11:52 pm

Did you run a compression test after installing the head ? Any possibility there is a micro-fracture somewhere that you can't see ? Are the bolts new or if not how old are they ? Are the bolts all the same length ? Thinkin' possibly right bolts but in the wrong holes. Old bolts might not torque correctly. Any washers involved ? Try retorquing after heating the engine up ?

All that said, I know only one thing about Hardleys, "They ain't fast !"

vinsanity69 · Post by **vinsanity69** » Mon Sep 10, 2007 7:13 am

I did do a compression test and I got 160 psi front and rear.The bolts are new as well as the washers and all are the same length.Got the engine up to temp and re-torqued.A fracture is a possibility.....the head is original and she is a '71.It looks clean,so is the jug..
I am going to take it all apart,again,and plasti gauge the mating surfaces.It is the only thing left I can think of short of replacing the head and jug. :sad

You are right about harleys not being fast.....unless your last name is McBride

Thanks Silver...

dragracer1951 · Post by **dragracer1951** » Mon Sep 10, 2007 8:23 am

Larry don't ride no Harley!!!!!!!!!
Does it have an aftermarket crank vent in it? Does it have an external oil return? How is the check valve. Has it been wet sumping?
If it does have an external oiler, check the lines . The crank vent you want is the plastic one. Because it won't wear your cases. Make sure it's timed correctly and make sure the clearance is correct.
What about the returns to the oil tank?
Is it pushing oil out the head gasket or somewhere else and making it LOOK like the head gasket?
Let me know

By the way...Yours is only three years older than mine.