Don Terrill’s Speed-Talk

I don't really like the Studebaker Champion flathead 6-cyls, but a nice guy begged me to do one for him. When I said no, he brought it in boxes, left cash and ran. First look at his block found four cracked exhaust valve seats, so I sourced a couple more core engines and dug in. Both the blocks checked out OK, so I reamed the lifter bores for .005" oversize lifters, had four cranks turned and three cleaned up at .020".

When we put a block on the line hone, we at first couldn't believe the Sunnen dial bore gauge; the two interior mains were .005" tight. How or even if it ran in that condition is lost to history, as this one had been disassembled and a shadetree rebuild started when we bought it. Not knowing or even thinking it mattered, we sent both cranks which came with it out to be ground. Again, because it was disassembled, there were no bearings to witness. Still, how would it have run with front and rear on spec and the two centers .005" tight? Wonder if the handyhack might have swapped mains from another block for some reason? Anyway, good that he didn't get any further with his project, because the crank would have been locked tight when those two mains were torqued. Just because, we got all four within .0002" now.

It gets better. I found some NOS .020" pistons for it on eBay at a good price. When they arrived, all clearly stamped .020", two of them measured out STD. (Yes, we've had some threads here about the recent perceived decline in parts quality control, but these pistons are fifty years old.) That they weren't a set is probably why they sat on someone's shelf all these years.

The plan is to cut the bottom of the guides to install positive valve stem seals and then hard exhaust seats.

Once the piston issue is sorted, I'd like to find the right ring groove spacers to install later, thinner moly rings. Designed in the late '30s, Studebaker used 3/32" top ring and 1/8" second and 5/32" oil. These 4" stroke little engines could benefit from the reduced friction of thin moly rings.

I had a Ford 390 block come through one time that had all 5 mains .002 under the low side. It was all original from the early 1970's.

I thought running PC seals on a fleathead engine was a Very Bad Thing. Correct me if I'm wrong.

Put a rebuilt 361" Ford FE in our F-600 Gunning Truck only to find that the bore was standard, but both mains and rods were ground.

Turned out the engine leaked antifreeze behind the flywheel under the bell housing. It never made a trip to a job!!

Had a sand cast pin hole in it from new. That's why it never was bored and rather just sat aside UNTIL it got used... And we got to use it, not funny...

Put another rebuilt 361" short block in it and didn't get 150 miles from town when a rusted "spot" on a valve spring let go and it dropped a valve. Asshole Mechanic put the heads by the drinking fountain in the shop!! It got the head, piston, rod, crank..... I forget if it cracked the cylinder or not?

Had a different Shop put a rebuilt 391" in it and all was fine..

pdq67

peejay wrote:I thought running PC seals on a fleathead engine was a Very Bad Thing. Correct me if I'm wrong.

I came up with the idea a while back and asked here if there would be any problem. Like most of my great ideas, just a few years late. A noted Ford flathead V8 builder answered and assured me he has been doing it successfully on many builds for many years.

How do things like this run, how about how some people even get them together?!

I had a guy some 20 years ago who dragged in his long block he just put together with the complaint that it would not spin over without massive force, and he was right!
When I finally got one piston out I found that he had ordered new rings other then what I provided to him, the rings he got where file fit which of course he did not do!!!!
It took me near one hour to drive all of those 8 Pistons out of the bore and I split 4 short sections of 2X4 in doing so!

To this day I do not know how he got those Pistons in each Bore, Nore how any of the rings did not crack, he must of assembled the motor in a 20 degree F meat locker or something!

DaveMcLain wrote:I had a Ford 390 block come through one time that had all 5 mains .002 under the low side. It was all original from the early 1970's.

And I've seen several 351Ms and 400s with mains .002-.005" *oversize*. They ran long enough to wear out and make it in for rebuild... one owner said the engine never did have good oil pressure.

dwilliams wrote:

DaveMcLain wrote:I had a Ford 390 block come through one time that had all 5 mains .002 under the low side. It was all original from the early 1970's.

And I've seen several 351Ms and 400s with mains .002-.005" *oversize*. They ran long enough to wear out and make it in for rebuild... one owner said the engine never did have good oil pressure.

I've run into that one too but not quite that bad. We've had those where the housings are right at or slightly above the high side and we just ground a crank to fit like a .009 under and give .002 main bearing clearance which worked fine. I'm not so sure about .005 over though, man....

Some of the old machinists talked about honing bearings to fit cranks.

If you read about Eddy Rickenbacker he supposedly poured a babbit bearing on the side of the road for a generals car and talked him into letting him fly airplanes(WWI).

Closer examination of the piston problem indicates someone may have used two of the pistons as a learning project on a skirt grinder. The skirts show evidence of being reground. Whomever was doing it wasn't getting the finished projects close to the same diameter. Why they were kept around is the mystery.

Then, there's the head and block deck. The handyhack who began the rebuild went after both with a belt sander of some kind and got the front end of the block .010" lower than the rear.



Installing positive seals required using a lathe to cut down the guides, then making a tool to extend through the lifter bores to drive on the seals.



With all the learning curve on this one, we can't charge the shop hourly rate, but solving problems is sometimes interesting.

PackardV8 wrote: ↑Mon Apr 04, 2016 12:56 pm Closer examination of the piston problem indicates someone may have used two of the pistons as a learning project on a skirt grinder. The skirts show evidence of being reground. Whomever was doing it wasn't getting the finished projects close to the same diameter. Why they were kept around is the mystery.

Then, there's the head and block deck. The handyhack who began the rebuild went after both with a belt sander of some kind and got the front end of the block .010" lower than the rear.



Installing positive seals required using a lathe to cut down the guides, then making a tool to extend through the lifter bores to drive on the seals.



With all the learning curve on this one, we can't charge the shop hourly rate, but solving problems is sometimes interesting.

I hate to bring this back up for this reason, but is this pic moving or am I seeing things? Thanks!

midnightbluS10 wrote: ↑Tue Jan 07, 2020 11:10 pm

PackardV8 wrote: ↑Mon Apr 04, 2016 12:56 pm Closer examination of the piston problem indicates someone may have used two of the pistons as a learning project on a skirt grinder. The skirts show evidence of being reground. Whomever was doing it wasn't getting the finished projects close to the same diameter. Why they were kept around is the mystery.

Then, there's the head and block deck. The handyhack who began the rebuild went after both with a belt sander of some kind and got the front end of the block .010" lower than the rear.



Installing positive seals required using a lathe to cut down the guides, then making a tool to extend through the lifter bores to drive on the seals.



With all the learning curve on this one, we can't charge the shop hourly rate, but solving problems is sometimes interesting.

I hate to bring this back up for this reason, but is this pic moving or am I seeing things? Thanks!

LOL
I think you are correct
It is moving

Some flat heads run really dry in the spring/guide pockets, this is exacerbated by a lot of low speed running, oil just does not get thrown around in there, unless there is a reservoir around the top of the lifer that gets agitated.

Maybe the flat head Ford was wetter in this area due to the lifters agitating the puddles of oil next to the lifter on each bank.

Flat head Harley's can run virtually dry in the guides if it is poked around on the road, i have pulled them apart bone dry.

Cheers.

It's a gif file, so it can move.

I recently encountered one of the aforementioned oddities with the 100K 305 I removed from my El Camino. I heard clattering noises, so I pulled the engine and installed a spare. The noise turned out to be a fuel pump coming apart. It had a rough Idle when hot and that turned out to be large pieces of the front main bearing missing causing low oil pressure to the front lifters. But wait, there is more! At a glance and a few quick measurements, the bores looked fine for a quick hone and re-ring. I spent $50 to get the block tanked, ordered flat top pistons, rings, and had the pistons hung on the rods. I went down the right side and then the left confirming most would clean up at about +.002 clearance, until I got to #7. This bore was the best looking of the bunch, but it was .005" over size. I went through the pile of original pistons and found a factory GM piston that measured .005" over. My machinist installed a sleeve, but having built thousands of engines he said he had never seen that factory oversize.