Brand New STD heads Leaking

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ahdra101
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Brand New STD heads Leaking

#1

Post by ahdra101 »

We just put a set of new std heads on a 5o pan and we are running into issues with the oil leaking up and over the lip on the cylinders and into cylinder itself. We are using the stock inside oiler set up Tried copper head gaskets, tried james beaded lead with fire ring, checked to make sure the bolts aren't to long, re checked valve seals and guides and they are all correct waiting to here back from std to see if they have any ideas.

Do you have any??
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Re: Brand New STD heads Leaking

#2

Post by RUBONE »

Are the recesses machined deep enough in the heads for the fire ring to clear when the gasket is on? Are the gasket surfaces on the head perfectly flat?
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ahdra101
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Re: Brand New STD heads Leaking

#3

Post by ahdra101 »

we bolted the heads directly to the cylinders while they were off the motor and they tightened all the down and the actual measurement was only a couple thousandths of an inch off so with the thicker james gasket that should have sealed that issue up

with the straightest straight edge we could find they were flat

we were thinking maybe they drilled the oil holes to long and that was causing an issue so i was just seeing if any one else had any issues with this

my boss has been a Harley mech since 1970's went to first time to Harley school was in 1980 first time he has had an issue like this so i was reaching out for experience from more old timers and old schoolers since there aren't many of those around any more
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Re: Brand New STD heads Leaking

#4

Post by steve_wood »

What about the gasket surfaces on the cylinders? Any peaks or valleys?
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Re: Brand New STD heads Leaking

#5

Post by Panacea »

I'm no expert either, Will the head sit down flat on the cylinder without the gasket in place? That would let you know if the recess is deep enough for the fire ring on the cylinder. And you could screw the headbolts into the head just till they bottom out and measure the remaining protrusion from the head, just to make sure the holes are deep enough. You could even place the gasket on the head to check oil hole alighnment, all ideas I'm sure you've already thought of... I also just read a post about STD heads that mentions the bolt hole under the intake has been shortend to clear the port... Mike
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Re: Brand New STD heads Leaking

#6

Post by mbskeam »

the fire ring must not bottom out before the gasket is under compression and a few more thou for expansion...
or it will leak....
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Re: Brand New STD heads Leaking

#7

Post by RUBONE »

As I said....
Robbie
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Re: Brand New STD heads Leaking

#8

Post by steinauge »

At service school we were told this problem is always caused by 1-high spigot\shallow head bore 2-head gasket surface not square with cylinder gasket surface 3- drainback hole in head too close to spigot.If its 3 you end up having to sleeve the drainback hole down a bit.
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