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Got the pistons in

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Basil

Basil

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Background: Ever since having my spitfire engine rebuilt by a "professional" shop, I have had a nasty leak out the back end. Twice I replaced the rear seal but to no avail. Finally, I pulled the motor and decided to tear it completely down and check everything as I out it back together.

Even though I had the shop install new flat-top pistons and rings, I checked all that as well. What I discovered was that the ring gap was more than twice the max gap allowed in all cylinders! So, I bought some new AE rings from Engels, and have finally gotten them installed (the right gaps are now perfect). Of course I will know for sure when I get it all back together whether the leak is better, but I surmise that I was building up excess crack pressure due to the excess ring gaps. The bearings were all well within tolerance, so I did not replace those (they were new when I had the last rebuild done. Now to get the rest of the little beat back together!
 
Um...we need pictures, even of seemingly silly things!
 
John_Mc said:
Um...we need pictures, even of seemingly silly things!
Click to expand...

Ok, how's this: :crazyeyes:
 

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Basil said:
...I surmise that I was building up excess crack pressure due to the excess ring gaps.
Click to expand...

I hate it when that happens! :jester:


Glad ya found the: "Ah-HA!!" issue. If the gaps were that wide, you can relax over the seal leak problem. You ~did~ run a 'dingleberry' hone thru the bores a bit to give 'em something to seat against, yes?
 
Let me see now...
Barberry
Bearberry
Bilberry
Blackberry
Blueberry
Boysenberry
China berry
Chokeberry
Cloudberry
Cranberry
Crowberry
Dewberry
Elderberry
Gooseberry
Huckleberry
Lingonberry
Loganberry
Mock Stawberry
Mulberry
Nannyberry
Raspberry
Salal berry
Salmonberry
Strawberry
Thimbleberry
Whinberry
Whortleberry
Wineberry
Wolfberry
Chuck Berry
Halle Berry
and even Knott's Berry Farm.....nope, no dingleberry!! LOL!! :laugh:
 
What jumps out at me, here, Basil is the: "rebuilt by a professional shop" part.

Guess it is what it is; but, isn't it soooo nice when the pros peform, well,
at professional level....like you can expect it to be right, and then it is?

I guess sometimes I expect too much.
 
The excess ring gap will certainly pressurize the crankcase; but why didn't the PCV system relieve the pressure?
 
Graham,

With four cylinders blowing pressure into the crankcase on every combustion stroke, the PCV simply becomes overwhelmed and it starts to leak oil at the weakest point.

Which is usually always the hardest and most expensive to repair.
 
2wrench said:
What jumps out at me, here, Basil is the: "rebuilt by a professional shop" part.

Guess it is what it is; but, isn't it soooo nice when the pros peform, well,
at professional level....like you can expect it to be right, and then it is?

I guess sometimes I expect too much.
Click to expand...

Well, I probably should have done a bit more research before picking a shop to do the rebuild. Too late to do anything about it now except to try my bet to put it back together as close to correct as I can (with a lot of help from folks here no doubt)
 
You're golden.

Reassemble.

:thumbsup:
 
Basil said:
...ok, got my socks on...
Click to expand...

That's a good first step ...
grin.gif


Good luck with the reassembly!

Matt

P.S. It's 13 degrees here so I have to live vicariously through you warm climate people!
 
What is the cc target for the chambers when you plane the head??I suggest 36 to 39 as a good figure.With the depth of the head gasket figured in 9.2 to 9.6 to one is user friendly .....with a nice boost in HP.
MD(mad dog)
 
Basil said:
DrEntropy said:
You're golden.

Reassemble.

:thumbsup:
Click to expand...

I'm trying to reassemble.....ok, got my socks on...
Click to expand...

DUDE!!

You owe me a keyboard.

...primarily for that avatar.

:shocked:
 
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