blown base gaskets shovelhead

[John Cham]

Hi Ive got a 77 electra glide with S&S cases and stock top end after putting the motor together after putting 10k miles on the bike I blew out my cylinder base gaskets I took the top end back apart went up to 20 over put the motor back together after 1k miles the base gaskets blew again I checked for blockages in oil lines screens checked oil springs ball took the screen out of the motor breather for less restriction checked flow back to the oil tank breather cap on oil tank everything seems ok I checked the top of the cases there true tried another set of cylinders put it back together after 11oo miles blew the gaskets again the motor seems to be building up to much oil pressure also oil lines to inner primary started leaking I've asked around and no one seems to know why this keeps happening been using all new gaskets tourqing down everthing doesn't make any sense so if anyone has any suggestions I would surely appreciate it thanks John

[Wrightturn]

Possible head bolts have stretched and causing false torque readings ????

[frisco-rigid]

Dozens of head and barrel installations and I've never experinced this prob so I can only wild guess..
Wright turn could be on to something if he meant to say barrel studs in the top of the cases stretching,, but like I said, I personally have not seen that happen,, ah,, could they be pulling out maybe..??
This prob started after 10K miles,, jeeeze, that's the confusion..
The motor breather you mention--- do you mean the breather in the cam case that breathes out the bottom rear of the motor..?? Although I haven't seen one strip it's teeth I guess it's possible,, and throw the breather timing totally out, or in-other-words,, no pressure evacuation..
BUT oil tank breather is apparently fine----- holy cow..!!

Ok, the only other thing I can come up with now is this---after you put it all back and start it up do you run it for only a short time --(15 mins. around the block gently for total warm-up)----- then park it to TOTAL cool down.. Then re-torque the barrel nuts and head bolts..??
Because I don't know what your experience is,, don't be offended if I tell you something that you already know ..
When you do your re-torque, you must totally loosen the top motor-mount (from head to head).. And I go so far as to always loosen the exhaust brackets and air-cleaner-to-head connection.. ANY connection at all that can prevent an honest re-torquing.. Also, when re-tightening those parts, they will re-tighten brand new up to re-torqued heads and barrels.. I'm anal that way..!!
Then, if neccessary, re-adjust & re-shim that top motor mount, while cold..
Shimming is your friend, it prevents the various parts from pulling and tugging on each other..

[Wrightturn]

Corrected. I can`t stay up that late anymore.

I have never had the problem on any HD but it did happen on a couple of cages.

My air cooled VW bus (the one I drove to Woodstock) pulled case studs and all kinds of leaks happened. All Tech 4 GM would stretch bolts or break them.

Flashback??????

[tagrat]

You know what they say, if you can remember the 60s you weren't really there!