Inline six curiosity (194 vs. 250)

[Alex V.]

Just a curiosity question:
Main journal sizes are the same on a 194 and 250, so... will a 250 crank fit in a 194 for a (when bored .030") 215 stroker?

['68OrangeSunshine]

Interesting question. I can't really say, not having much contact with L6s smaller than a 292. I know the prior generation of Chevy L6s were sold in 215, 235 and 261 CI displacements. Heavier cast iron blocks, though. The next Generation, from 1963-87[?] ran 194, 230, 250 and 292. 230s were not used in trucks after '67.
I have heard of racers building "Cheater 292s" by using a 292 crank in a [1-7/8th inch lower] 250 block with oversize diameter pistons, for getting around racing class rules. I don't race so I only have heard of it in passing.
You might ask around at Inliners International. Someone there might know about it.
www.inliners.org

[D13]

Yes it will fit, basically need to drop in the 250 pacakge with only the pistons from the 194. A 230 has the 250 bore and 194 stroke.
Check the rod clearance at the bottom of the bores as the 194 has the smaller bores.
An unusual combination, as the small bore of the 194 limits valve size and breathing potential.

[GRX]

There are a couple good reasons you do not see this.
One - it would require custom made pistons. Shorter pin height because of the longer stroke.
Two - being under square (stroke longer than bore size) it would not be conducive to performance.

[Tom]

Originally Posted by GRX

Two - being under square (stroke longer than bore size) it would not be conducive to performance.

Tell that to the Ford modular motors.
Oversquare does not equal performance. The thing here is enough bore size to fit big enough valves and them not be shrouded. Once you've accomplished that then added stroke will just add HP.

[Alex V.]

Not everyone wants to build for horsepower - torque in the usable RPM range can be conducive to economy, and stroke can be conducive to torque. It was a question out of curiosity.

[GRX]

Originally Posted by Tom

Tell that to the Ford modular motors.
Oversquare does not equal performance. The thing here is enough bore size to fit big enough valves and them not be shrouded. Once you've accomplished that then added stroke will just add HP.

Somewhat apples to oranges comparison regarding valve train designs and related performance characteristics, but yeah. My bad for not being more specific.

[Wrenchbender Ret]

I understand all the heads for those engines used the same size valves. The 194 heads had smaller combustion chambers to keep the comp. ratio the same as the others. Some use this head on the larger engine for more comp. There was a 215 version of this engine. Pont. used it in Tempest models. Some had the standard head & some had o-head camshaft with a cog belt drive.
George

['68OrangeSunshine]

Originally Posted by wrenchbender ret

i understand all the heads for those engines used the same size valves. The 194 heads had smaller combustion chambers to keep the comp. Ratio the same as the others. Some use this head on the larger engine for more comp. There was a 215 version of this engine. Pont. Used it in tempest models. Some had the standard head & some had o-head camshaft with a cog belt drive.
George

1.6'' in, 1.5'' ex.

[D13]

The 194 head has smaller chambers, which raises compression, but has siamesed exhaust ports, degrading ability to use headers. Also the smaller chamber and small bore will shroud valves larger than stock, limiting the upper RPM breathing if used on a 250.

The crank will drop in but the compression height on the pistons is different, so custom pistons or rods will be needed. Custom rods with 50 year old piston technology... better off doing the pistons.

Unless your racing class has a CID limit, for the same cost, you can build a 250, use 305 1.8" intake valves, 1.6" valves on the exhaust, and make more power. Or leave it stock and use the longer stroke and 50 extra CID to make more torque.

Kind of why GM only put the 194 in the Nova - wouldn't pull a truck or Impala. Increased bore to make the 230 then stroked to make the 250, which is a pretty decent engine.

[TJ's Chevy]

Or leave it stock and throw 5 PSI on it.

[Alex V.]

Originally Posted by TJ's Chevy

Or leave it stock and throw 5 PSI on it.

That's within the realm of possibilities. But if it's possible, why not add 21 cubes (mostly in stroke) *then* boost it?

[TJ's Chevy]

Originally Posted by Alex V.

That's within the realm of possibilities. But if it's possible, why not add 21 cubes (mostly in stroke) *then* boost it?

That works to haha Best thing in my book would be to get a 292 and boost that....so now your adding almost 100 cubes!