I bought this 1965 327 in a non-running condition with a cracked cylinder wall. It has the right casting and date codes for one of my cars, which is why I wanted it.

From what we can tell, it only had a few miles on a rebuild when a careless mechanic changing a carburetor or intake dropped gasket material into the intake manifold. I found gasket material jammed between the piston and cylinder wall on the cracked cylinder. The pistons (Speed Pro forged) look fine.

We had a reputable shop bore and sleeve that cylinder. Otherwise, the block looked perfect. The shop also checked the pistons and crank. They said that they thought it had been built for racing because it had extra clearances in several places. According to them, the Speed Pro forged pistons have an extra .003 clearance to cylinder walls over what they would normally give it. If we understood them correctly, they also said that the crank/bearings have an extra .001 of clearance. Thoughts? Does this sound normal or correct?

As a result of the extra clearances at the crank, they recommended a high volume oil pump. So I'm not sure whether to reuse the old pump, which seems to be a standard volume pump. The pump that was in there has M55 cast into the body (Melling standard volume?), with the numbers 218 31 on it. Does anyone here recognize this number or know what it means? How old might this be? Is this one of the stronger old design Melling pumps?

Also any opinions on whether we should go with a high volume pump will be appreciated. This engine won't be raced and will only see average street use.

Thanks for your help.

I bought this 1965 327 in a non-running condition with a cracked cylinder wall. It has the right casting and date codes for one of my cars, which is why I wanted it.

From what we can tell, it only had a few miles on a rebuild when a careless mechanic changing a carburetor or intake dropped gasket material into the intake manifold. I found gasket material jammed between the piston and cylinder wall on the cracked cylinder. The pistons (Speed Pro forged) look fine.

We had a reputable shop bore and sleeve that cylinder. Otherwise, the block looked perfect. The shop also checked the pistons and crank. They said that they thought it had been built for racing because it had extra clearances in several places. According to them, the Speed Pro forged pistons have an extra .003 clearance to cylinder walls over what they would normally give it. If we understood them correctly, they also said that the crank/bearings have an extra .001 of clearance. Thoughts? Does this sound normal or correct?

As a result of the extra clearances at the crank, they recommended a high volume oil pump. So I'm not sure whether to reuse the old pump, which seems to be a standard volume pump. The pump that was in there has M55 cast into the body (Melling standard volume?), with the numbers 218 31 on it. Does anyone here recognize this number or know what it means? How old might this be? Is this one of the stronger old design Melling pumps?

Also any opinions on whether we should go with a high volume pump will be appreciated. This engine won't be raced and will only see average street use.

Thanks for your help.

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Need to know the clearances
What is an "extra .001" ?
The piston clearance will have no effect on the pump but I do not have a clue why anyone would put .003 extra in, this is insane :noway:

You could have the pistons knurled if you want to use them, old school but it does work, been done & is still done on big truck rebuilds
Not too many places have a knurler around anymore though.
I have one I haven't used in probably 20 years more than a few times but I ain't exactly around the corner from you,, :D

If you can post a pic of the pump neck it is very easy to tell if it is the new one.
It will look like it is cast around the oil passage that leads to the rear main rather than being more "square" shaped or flat on the sides all the way up.
You can feel where the passage is with your fingers on the new one.

Mike,

Don't some of the stock hyper's now being used go down to as low as .0015" skirt clearance so if they are the older Speed-pro's, won't they be like .0035" to even .004"????

She might clatter cold then warm up and quiet down and use a schosh more oil, but I figure he should be OK!!

And right about "knurling" piston skirts!!

It was done a lot back when I was a kid!! That and valve guides too, BUT not the best like you say, imho too....

pdq67

have the crank gound properly to the next undersize. this has no downside and fixes the problem right. band-aiding it with a HV pump is very poor solution.

if it were mine I'd bore it next oversize and get decent cylinder finish and clearance. the clearance is built into the piston skirts, the cylinders are finished to size like 4.030 or whatever. If you put it together like that you're essentially building a pre-worn out engine. Whoever built that thing was stuck in the 60's.

Mike,

Don't some of the stock hyper's now being used go down to as low as .0015" skirt clearance so if they are the older Speed-pro's, won't they be like .0035" to even .004"????

She might clatter cold then warm up and quiet down and use a schosh more oil, but I figure he should be OK!!

And right about "knurling" piston skirts!!

It was done a lot back when I was a kid!! That and valve guides too, BUT not the best like you say, imho too....

pdq67
=
Yes, the hypers can go down to .0015 & even less
Actually some of the older TRW/SpeedPro were .005+ years ago but this has nothing to do with the bore size.

As Tom said, the clearance is in the piston, you don't add it to the bore except for a little in certain applications like a marine engine.

So a little more info is needed before recommending a cure like what piston, what is the actual clearance in both the pistons & the bearings we are talking about.
Is this a standard crank? If so it is possible you can close the clearance up with .001 bearings
Not enough info for a good answer ;)

the combination of loose bearing clearances, HV pump and loose pistons is a receipe for an oil burning, plug fouling engine.

Thanks everyone for your suggestions.

Mike, you are right; I'll try to get more information. I don't know for sure if the shop meant that the piston to cylinder wall clearance was .003. If that is the case, I probably don't need to worry about it as that sounds normal for older Speed Pro pistons. If it is .003 plus another .003 or so, that likely would not be good. I'll also try to find out more about the crank specs. I do know that it is a forged 327 crank.

The shop is supposed to be experienced and good at building performance engines. They did say that they thought the engine had very little time on it since the last rebuild. They looked at the parts and supplied the rings and bearings that they recommended.

I can post again if/when I get more information.

Tell me about loose!!

My oldjunk301 was about as loose as they came and sure it clattered, leaked as well as used some oil, BUT it RAN FINE by me!!

It was my daily driver for quite a while and boy did I beat on it!!

pdq67