R3 Passages!

[mfg]

 There are smaller coolant holes between the cylinder block and cylinder head in authentic Paxton R3-4 engines, reason being.................?

[Nelson]

Maintain or increase distance from cylinder bore edge to hole edge in water jacket.

[mfg]

26 minutes ago, Nelson said:

Maintain or increase distance from cylinder bore edge to hole edge in water jacket.

Perhaps...however, I tend to think the smaller passages are there for an entirely different reason!

[mfg]

HINT!.....Think of who built those engines...and then consider what other major engine project they, at the time, were working on!

[Gunslinger]

Prototyping for the 340cid engine?

[Nelson]

Are you talking about the 342 block? I think the hole needed to be smaller for the increased bore diameter on this block. Bore diameter and chamfering made it useful for the R3/4.

[mfg]

1 hour ago, Gunslinger said:

Prototyping for the 340cid engine?

Not easy to get one by Gunslinger!!

[mfg]

1 hour ago, Nelson said:

Are you talking about the 342 block? I think the hole needed to be smaller for the increased bore diameter on this block. Bore diameter and chamfering made it useful for the R3/4.

Well, I was told it was something north of 350 CI....Anyway, an unfinished block was brought up this way in '67 or '68...it came from a SB scrap dealer, and a Studefan from Dedham grabbed it as an oddity....along with some other 'normal' parts....I didn't pay much attention at the time.....He said regular 289 heads would not fit it, and coolant passages were drilled half size to increase internal block pressure  (never was sure what that meant!)

[Nelson]

Well, here are two photos of the 342 block with standard size Avanti piston in the bore to show the difference in bore size. The small hole is between the cylinders.

[mfg]

19 minutes ago, Nelson said:

Well, here are two photos of the 342 block with standard size Avanti piston in the bore to show the difference in bore size. The small hole is between the cylinders.

It's really too bad Studebaker could not have hung on a bit longer and got this engine fully developed and released to the public.... They were, obviously, very close!