De-stroked engine?

[53k]

I understand stroking an engine, but how would one de-stroke an engine? I am helping a man sell his dad's Avanti and he described the engine as "slightly de-stroked".


[img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/R-4.JPG[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/64L.JPG[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/64P.jpg[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/53K.jpg[/img=right]Paul Johnson, Wild and Wonderful West Virginia
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine
1962 Gravely Model L (Studebaker-Packard serial plate)
1972 Gravely Model 430 (Studebaker name plate, Studebaker Onan engine)

[DEEPNHOCK]

swag...
Check to see if it was rebuilt using a 259 crank and pistons.
Jeff[8D]

quote:Originally posted by 53k

I understand stroking an engine, but how would one de-stroke an engine? I am helping a man sell his dad's Avanti and he described the engine as "slightly de-stroked".

[JDP]

Probably installed a 259 in place of the 289..

JDP/Maryland

[Mike Van Veghten]

53K -

To answer your question...it's done the same way a crank has stroke added. Just has weld material added to the other side.

Mike

[DEEPNHOCK]

While technically the correct answer Mike...
Do you really think an engine rebuilder would go through all that work to 'de-stroke' a Stude V8?
Have you ever heard of any Stude V8 being de-stroked?
(except maybe an Indy engine?)
Maybe he reground the the crank a little off to save it?
Then ALL the rods big ends would need work.
I tried to fit the most plausible answer to the question.
And the question was based on info supposedly told to the owner.
Maybe that was the easiest explanation to give the guy as to why he lost 30 cubic inches of displacement.
I don't know, but I wasn't splitting hairs for the sake of splitting hairs.
Jeff[8D]

quote:Originally posted by Mike Van Veghten

53K -
To answer your question...it's done the same way a crank has stroke added. Just has weld material added to the other side.
Mike

[buddymander]

"Slightly" destroked? Maybe he meant "slightly detuned" or slightly degreased".... Slightly decomposed?? The tremendous amount of machine work involved in destroking an engine; even "slightly" should not be taken "lightly".

[klifton1]

It seems to me there was one destroked to under 200 ci out at Bonneville a few years ago. I can't find the aritcle and don't recall how it did.
Klif

55 Speedster

[JRoberts]

quote:Originally posted by DEEPNHOCK

[navy][b]While technically the correct answer Mike...
Do you really think an engine rebuilder would go through all that work to 'de-stroke' a Stude V8?
Have you ever heard of any Stude V8 being de-stroked?
(except maybe an Indy engine?)

The only one I have ever heard of was run in a '53/'54 coupe at Bonneville many years ago. Looking at the class breakdowns the owner decided that he could not compete in D or E classes so destroked and sleaved his Stude V-8 down to something less than 183 cu.in. Yes he did set a record.

Joe Roberts
'61 R1 Champ
'65 Cruiser
Editor of "The Down Easterner"
Eastern North Carolina Chapter

[PackardV8]

FWIW, a 224" crankshaft in a 232" block gets right down to 201" without any machine work whatsoever.

thnx, jack vines

PackardV8

[Mike Van Veghten]

Jeff (deep) -

Hey..I just answered the original question...
"I understand stroking an engine, but how would one de-stroke an engine?"...!!
It was also done quite abit in the drag racing old days. I know many an engine was welded and "destroked" to make a weight break in the old days before the "machine to your specs." crank shafts of today.

So beat on me some-more!

Mike

[klifton1]

Joe
That's the one.
Klif

55 Speedster

[53k]

[quote]quote:Originally posted by DEEPNHOCK

While technically the correct answer Mike...
Do you really think an engine rebuilder would go through all that work to 'de-stroke' a Stude V8?
Have you ever heard of any Stude V8 being de-stroked?
(except maybe an Indy engine?)
Maybe he reground the the crank a little off to save it?
Then ALL the rods big ends would need work.
I tried to fit the most plausible answer to the question.
And the question was based on info supposedly told to the owner.
Maybe that was the easiest explanation to give the guy as to why he lost 30 cubic inches of displacement.
I don't know, but I wasn't splitting hairs for the sake of splitting hairs.
Jeff[8D]

Originally posted by Mike Van Veghten

53K -
To answer your question...it's done the same way a crank has stroke added. Just has weld material added to the other side.
Mike

Actually, Mike's answer may be exactly what was done. I have known the original owner for many years. Unfortunately he has terminal Parkinsons and can't even communicate anymore so there is no way to really find out. However, he used to race Packards (yes, V-8 Packards- he even built himself a Packard-powered race car). He was very clever about engine lower ends. He completely restored this Avanti, frame off, himself, over a period of several years.


[img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/R-4.JPG[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/64L.JPG[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/64P.jpg[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/53K.jpg[/img=right]Paul Johnson, Wild and Wonderful West Virginia
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine
1962 Gravely Model L (Studebaker-Packard serial plate)
1972 Gravely Model 430 (Studebaker name plate, Studebaker Onan engine)

[64Avanti]

"Do you really think anyone would go to all of the trouble to destroke a Studebaker engine?"

Of course they would!

My Bonneville engine is a destroked over bored 259 that is right at 260 cu in. This was done to keep the displacement under 261 in cu and have as large a bore as I felt was safe for a suppercharged engine. This was done by offset grinding a 259 crankshaft to a "Honda journal size". The stroke is 3.15 inches.

I hope to some time in the future build a 183 cu in engine for use in another Bonneville car. However I must first set a record at over 200 mph with the Avanti.

David L

[wally]

The other day, a boy at work said he bought a 80-something Kamero with a 1969 Kamero 302 engine that had been stroked by a previous owner to 355 cid. He knows little else, and won't provide the block casting and stamping #'s to shed a little light on the subject. I figure that he prolly has a +.030 350. It has a rumpty-rump cam, chrome on the motor, and he is happy. With some people, talk is cheap & all that matters. The facts are confusing and just get in their way. So, why bother trying to educate them?

"You Can't Have Everything--Where Would You Put It?" ---comedian Steven Wright

[Dan Timberlake]

It could be a semi-vintge terminology thing. Some piston manufacturers mention they make/made their oversize pistons with slightly shorter deck heights or domes to keep compression ratio closer to the OEM value. Not that a 0.030 inch over bore increases displacement enough to raises the mechanical compression ratio much either. Pistons made this way were often called destroked even though the engine's stroke is 100% crank controlled.