Engine: Pistons question for my R3 engine

[Dwight FitzSimons]

My R3 (B69) (short block) has been at my engine machine shop for a while. I just got a call from the engine builder with the statement: "come on down here; I'll show you what you got." Background: The oil pump had failed and the rod bearings had wiped some babbit onto the crank. The cylinders appeared to have some light scoring. The engine has gap-less rings

I'll have a short time (days) to tell him what direction to take on the engine (or I'll lose my turn). Some questions might be:
--New Hypereutectic pistons and a little-as-possible overbore? (Currently has original forged pistons - would like to keep, but not essential.)
--Don't know what else (that's why I wrote this topic)
--My nightmare would be that I need one or more rods

I intend to run the engine both at Bonneville and the drags. Just kidding, just mild street use.

Thoughts?
Thanks,
--Dwight

[Buzzard]

Decades ago when I built my R4 Clone, I used Jahn's Forged 12.5 : 1 slugs. It is still running very strong today.
Bill

[PackardV8]

Decisions, decisions.

If you want the most authentic R3 and if the scoring is minimal, one might hone the cylinders, knurl the forged pistons, new rings, good to go.

If you want the best street engine, go with the next overbore size, hypereutectic pistons and moly rings. Problem is, moly rings are difficult to find in Stude diameters. Total Seal will make them up for you, at a cost.

Most likely, your rods will be OK. They seldom are ruined without more damage than you describe.

jack vines

[M-Webb]

I thought R3 blocks were basically already bored out to the max. If so, how are you going to bore it out any more? Maybe need to sleeve the affected cylinders instead?

[Dwight FitzSimons]

Yes, but my brother has an R3 that is supposedly 320 cu. in. (engine built 2 owners back) Presumably bored ~0.180 in. Wonder how many cylinders had to be sleeved?

[StudeRich]

I would save those Forged, Forged True Pistons no matter the use for one reason, they and the Rods are balanced to the Crank.
On the other hand, if you can't afford 100+ Race Gas, maybe that would be a concern.

[Dwight FitzSimons]

Yes, if the pistons are reusable then another R3 short block (minus the rods) could be built by boring a 259/289 block out 0.093. Those cylinders would then be perfectly round and these ForgedTrue pistons would fit in that block perfectly.

Wait a minute! There's nothing unusual about an R3 bare block except that they were hand selected for lack of core shift. Perhaps I should go that route in building back my R3, because I could keep the original forged pistons !?

As Jack says, decisions, decisions.

Cost of racing fuel is irrelevant to these decisions because of low annual mileage.

[bezhawk]

On B61, we had rust in #5 and 7 cylinders, and bored it out .015. Got forged pistons custom made from Diamond Racing Pistons. Jaguar rings will work good, and are Moly. I just got in another R3 yesterday, but haven't tore it down yet. That's in addition to another one in the shop, and two R2 engines. One with custom Arias pistons and Carillo rods. We do have custom H beam Carillo clones that we had made. I also have stock new forged true NOS pistons. I'll have Snider regrind the cam and lifters.

[Dwight FitzSimons]

Update:
I just returned from the engine builder. The crank appears to just need polishing. The cylinders, however, have (not sure of right term, but I'll use) taper that varies from top to bottom & "clock angle" (3, 6, 9, 12) that one would expect of a Studebaker V8 with close to 100k miles on it. That is, kind of worn out.

One consideration that I'm keeping in mind is the resale value of the car (not an original R3 car). This may be when my heirs inherit the car, but still is a consideration.

I have thought about Jack Vines' sage advice above. Being an engineer (retired) makes me lean towards Jack's second option: best street engine. I like to see things done well. That means boring it out the minimum amount needed to make the cylinders the same diameter at all points of measure. It'll be a street engine, so I'll use hypereutectic pistons and moly rings. I assume that the piston-to-wall clearance should be on the high side of that for an R1 or R2.

So, I'll have to investigate sources of hypereutectic pistons & moly rings. Meanwhile, the engine builder will over-bore the cylinders.

Thanks for all the info & advice.
--Dwight

[Studebakercenteroforegon]

A common rule is don’t bore your engine block until you are holding the pistons in your hand.

[PackardV8]

As mentioned, there's nothing special about an R3 block other than the serial number; magic to some, unimportant to others.

The most cost-effective street engine is to start with another block, bored to .060", readily available hypereutectic pistons; the resultant 299" is a great build. It's also much quieter when cold compared to forged pistons

With your R3 block, I'm not aware of any hypereutectics available in that bore diameter.

FWIW, we've often bored Studebaker blocks to .118" oversize and used Ford cast pistons. That gives 308" and a good street build.

As Brad suggests, staying with the R3 block and custom forged pistons makes a good, albiet very expensive street engine.

jack vines

[DEEPNHOCK]

Sounds like a fun project... But...
100,000 miles on a "B" engine?
Wouldn't you think the rarity of a B engine would want you to keep it together?
Not saying anything, but just curious.

[Dwight FitzSimons]

Your point is well taken. I do have a (fairly wide) originality streak in me.

[Dwight FitzSimons]

No one has mentioned sleeving all 8 cylinders. Maybe there's a reason they haven't.
--Dwight

[PackardV8]

No one has mentioned sleeving all 8 cylinders. Maybe there's a reason they haven't.
--Dwight

It's just time and money; $100 a hole and up. Afterward, the block requires line honing and square decking, but we do that on every rebuild. Just be sure your shop is including these in the sleeving RFQ.

If a typical precision block machine quote (clean, mag check, bore, diamond hone cylinders, line hone main bores, square deck block surface) is $750, with sleeving all eight holes, it would be at least $1500.

jack vines

[M-Webb]

Not my money, but I would think a cost of less than $1K to save and reuse the original R3 block for a real R3 build is a small price and just part of owning the legacy and history. I had my clover leaf block sleeved on all 8 cylinders because of over bore and core shift and that is just for a pseudo Frankensteined R2-ish kind of build. If I had a full on legit R3 motor like I think we are talking about here, I don't think it would be much of a question if it were mine.

Now what kind of piston you put in it, that's questionable as that is somewhat of a hidden replaceable part. However, I thought the R3's had unique pistons in them as well. If so, I would at the very least save them even if using something else better for actually running the motor. You can't see the pistons when done, but you can definitely see and read a block #, plus that is the core main part of the motor obviously. Once you replace the block, it is more just an R3 clone. With the correct block, and all the other unique parts, it IS an R3 motor, not just a clone.

If I had a real R3 motor I wanted to run on the street, I would just de-tune it internally to allow for that doing things that are reasonably reversible and save all the original parts no matter what. I guess you could treat the block as just another saved part and use a generic block to actually run. Functionally it would work, but not really the same thing. But as long as you don't lose the original block and other parts and they stay with the same ownership, don't get separated, it is all just a pile of valuable unique parts one way or another at a certain point. But if parts get scattered in the wind and lost track of for whatever reason, then unique and rare history will get lost and probably little to no chance of getting it back. R3 parts spread out wherever is not the same thing as a together legit assembled and running R3 motor of course.

How many real R3 are even out there? I thought there were only a handful or 2 of them. Not something one would typically want to randomly do +/- builds on.

[PackardV8]

First, we bow to Brad as our resident R3 build expert. He's probably seen more of these than anyone.

As mentioned previously above, all Studebaker V8 blocks came out of the same foundry and went through the same machining line. They only received a serial number hand stamped upon final assembly. For some, those blocks which received an R3-series stamp might as well be made of gold. For others, a worn out R3 block is just an unneeded expense on the way to a rebuild; and they're both right. It's just time and money; only if it's yours does it make a difference.

And yes, the R3 heads, intake and exhaust manifolds, rocker covers, et al, are externally visible, but the special crankshaft, rods, pistons, cam, et al, aren't. Many R3 blocks and heads no longer have the original internals.

And, to further confuse the issue, after Studebaker-Packard ceased engine production, Paxton continued to stamp blocks with R3 serial numbers and sell them across the parts counter. At some point, they ran out of R3 connecting rods and cylinder heads, but they kept selling "bitsa" R3 engines. Thus, there are orders of magnitude more R3s out there than the nine genuine factory-installed ones.

Not sure if we have reliable data, but IIRC, some opine there were 200 R3 heads cast.

And to further confuse the issue, there are the early 299" versions which had special serial numbers but did not have the R3 heads

And to further confuse the issue, not all the nine original R3 Avanti still have their original engines.

jack vines

[Dwight FitzSimons]

I suggested sleeving all 8 cylinders of my R3 engine to my engine builder, but he didn't like that option. Rats! Just when I reach a solution he throws a monkey wrench into it. He said that weakens the deck too much. He doesn't want to sleeve more than 2 cylinders on an engine.

Is the Studebaker V8 block particularly strong wrt this issue?

Now, it appears that this option is off the table. What say y'all?

Thanks, Dwight

[PackardV8]

We respectfully disagree with your builder; this is not a SBC. The Studebaker block is heavy-as-hell-for-stout. We've sleeved all eight holes with complete success.

jack vines