How to make stroker 360 with 273 crank?

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RDJ

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I talked to a guy who is selling an engine. He said that he has an internally balanced 360 stroker using a 273 crank. How do you get a stroker 360 with a 273 crank? Please pardon my ignorance. I am new to the small block.

BTW, the basic specs for the engine are 9.5:1 CR, aprox [email protected] and .512 lift cam, flat top pistons, Edelbrock RPM intake.
 
360 block and a 273 crank can be used with bearing spacers. http://chucker54.stores.yahoo.net/ma360mabesp.html
The use of these mean bearing spacers requires the alignhonement of where the crank sits. Now you can use a standard 273/318, 340 crank.

A 360's 4,00 inch bore with the 3.31 crank yeild 333.1 cubes. At .030 it's 338.1 and @ .060 over it's 343.1.
 
hows that a stroker at a 343? if the 360 is bigger at start
 
It is destroked. The term stroker is usually describing long stroke engines. toolman
 
The term "Stroker" refurs to changeing a engines stroke. Most common is up stroking. Or just "Stroked" for increasing the stroke.

Destroking is not so commonly seen since no one wants to go down in cubes. Though there can be an advantage to this in class racing.

The difference between long and short stroke engines is debateable.
 
Hence my confusion. I assume "stroker" meant increasing the stroke, and I wondering how this could be done with a 273 crank. Apparently you can't? Anyway, is this common? The internal balance sounds good. Any opinions on this kind of build?
 
RDJ, before stroker cranks were readally available ,I built a 340 stroker many years ago using a 273 steel crank.The stroker cranks that were available back then were very expensive.I sent my 273 crank to Lunati and they welded the rod bearing journals ,then offset ground the journals to increase the stroke.Then they annealed and heat treated the crank. They increased the stroke to 3.79". The 273 cranks have a smaller converter pilot hole, so you have to get your coverter pilot turned down. How many cubes is this 360 that you are looking at?
 
Wasn't the 302 Chevy a de-stroked 327? Wasn't the Boss 302 a de-stroked 351 Cleveland? I believe these were de-stroked for Trans-Am rule compliance back in the 60's-'70's. And Chrysler did something similar with the Posey and Gurney efforts, although I don't know whow they achieved the legal displacement.
I always thought the goal of displacement was for a motor to wind up quicker and produce HP in a higher RPM band than a larger motor.
Rebel: How did that "stroker" crank hold up for you back in the day?
 
Hi Clifftt,it's been around 13 years, a couple of rebuilds and head and intake combinations, still using the same crank today.
 
Cliff, 303.8 CI destroked 340 is how they did it!!! Over square short stroke rev monster making 440 hp!


Factory production AAR Cuda's and T/A Challenger's were certainly no slouch's either.

Production 70 AAR Cuda Specifications:
Wheelbase, inches: 108.0
Weight, lbs: 3,600
Number built: 2,724
Base price: $4,340

Standard Engine
Type: ohv V-8
Displacement, cid: 340
Fuel system: 3 x 2bbl.
Compression ratio: 10.5:1
Horsepower @ rpm: 290 @ 5000
Torque @ rpm: 345 @ 3400

Representative Performance
0-60 mph, sec: 5.8
1/4 mile, sec. @ mph: 14.4 @ 99.5
 
clifftt said:
Wasn't the 302 Chevy a de-stroked 327?
Click to expand...
I forget, but it was a destroked 327 or 350. The bore was 4 inch or so like most of GM's were then.


Wasn't the Boss 302 a de-stroked 351 Cleveland?
Click to expand...
No, there different engines completely. The 302 was as it is. A 302. Not stroked or destroked in anyway.


I believe these were de-stroked for Trans-Am rule compliance back in the 60's-'70's.
Click to expand...
Just GM and Chrysler. Oh wait, The AMC's may have been, I don't know if there 5 ltr. engine was a stock offering back then. Might have been.

And Chrysler did something similar with the Posey and Gurney efforts, although I don't know whow they achieved the legal displacement.
Click to expand...
As said above, they destroked the 340 with a crank that is no longer made.


I always thought the goal of displacement was for a motor to wind up quicker and produce HP in a higher RPM band than a larger motor.
Click to expand...
The goal of stroking a engine is to achieve a displacement favorable for the need of the car/driver/race course or track at hand. Be it going up or down in cubes.
Quicker reving engines will have a shorter stroke followed by lighter weight rotating assembly. The RPM limits are determined by these factors as well as valve train specs, cam, springs, valve and ports of the head. Intake, carb and exhaust system play a roll.
 
So I went up there today to check it out. He's not really sure what it is. All he knows is that is built by a good shop, 9.5:1 CR, cam is .513 or .525 lift (not sure), doesn't really know the duration. 360 HP. Flat top pistons, but doesn't know what kind. He thought it was a stoker with 273 crank internal balanced engine. Has a rebuilt 727 with heavy duty clutches etc, to go with it and a 2800 stall converter. All never run, but it was built 5 yrs ago. He wants $3,000 for all of it.

A number on one of the runners on the head was 9694407. What kind of head would that be?

HOWEVER, the converter has a butterfly weight, so that would seem to be contrary to an internal balanced engine. So, maybe he does have a stroker crank, and not a 273 crank?

To his credit, he is a body/fabricator guy. One of his projects (under construction) that I saw was a late 30's Plymouth truck he put on an early Dakota frame, fabricated a hydraulic lift bed, some kind of air ride suspension so it will ride low. He was going to put this engine and trans in it, but decided to go with a magnum fuel injected motor. For his engine needs he used his trusted shop to put together the right combo, but it was in a town he moved from a few years ago.

Anyway, I couldn't just plop down all that cash unless I could get more info. BTW, he has a good rep and is a good guy, so I'm sure he isn't trying to pull a fast one. I may still get it or just build the 360 I have. I need to think about it.

I have never rebuilt a motor before though, so the possibility of me screwing it up is good. Thanks for listening.
 
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