De-Stroked 360?

[indy swinger]

Ran in to this old guy yesterday and was talkin bout cars and my plans for my 360 ( 408 stroker ) when he said why not take my 318 crank and rods and build a d-stroked 360, said it would be a wild little motor with tons of power. He made me a little nervous cause he was old and drove a Chevy, so smiled and said i had to go! Has anyone heard or done this and what is envolved?

[dwc43]

Why in the first place would you want to destroke a 360 when you could just build a smaller 318? Second thing, the 318 crank wont fit in a 360 cause the 360 uses larger main bearing journals than a 318 or 340 so it's impossible to do in the first place. Third, you'ld make less power with that set up, not more. Stroke your 360 and stop listening to chebby guys that aint gotta clue.

[Shaun]

Indy, I have seen people destroke engines before and they are whiners-really rev high and fast. But I agree with DW,the mains on a teen are 2.5 and the mains on a 360 are 2.625. You'd have to weld and grind the mains just to get them into the block!!
What the old man was talking about is the same concept the 340 was built on. It has a short stroke(3.31-the same as the 318 and a fairly good size bore 4.04-.095 bigger than the 318). The 360 has a 3.58 stroke and a 4. inch bore-it has more bottom end(weight wise too,so it doesn't rev as fast).
So if you are planning on going that route,bore out the 318 as far as you can get it(sonic check the block first) and the rest will be history.Or just find a 340.
Shaun

[it's all dodge]

And if you get custom pistons with the thin rings, the bore size of 318+ anything less than a 4 inch bore, the rings are a small fortune. If you have an early (74 and earlier) 318 you should have no problem boring to 4" (more selection in rings, about a 333 cid.) but be good to sonic check. I looked up rings for my .060 over 318 to maybe use with my lightweight Ross pistons for an oval track engine, not much out there for a 3.97 bore. if the rules for next year let me, it wouldn't cost much more for a stroker. 410 Anybody here buy the 4" stroke 340 main size noduler crank from Ohio Crankshafts?

[B1owner]

Originally Posted by it's all dodge

And if you get custom pistons with the thin rings, the bore size of 318+ anything less than a 4 inch bore, the rings are a small fortune. If you have an early (74 and earlier) 318 you should have no problem boring to 4" (more selection in rings, about a 333 cid.) but be good to sonic check. I looked up rings for my .060 over 318 to maybe use with my lightweight Ross pistons for an oval track engine, not much out there for a 3.97 bore. if the rules for next year let me, it wouldn't cost much more for a stroker. 410 Anybody here buy the 4" stroke 340 main size noduler crank from Ohio Crankshafts?

I bought a Ohio 4 inch crank with the 340 mains. Nice. Journals within .0002. Ohio's cranks are cast by Scat, the same people who cast Mopar performance's 4 inchers. Ohio is also cheaper, and IMO a better ground piece.

[it's all dodge]

So if it's also made by scat, would be knife edged too? A 340 flywheel and balancer, right? It is for internal balance, right? The mopar are a little behind on the stroking small blocks, but it's gaining speed, fast! Alot better than stroking a 350, the small block dodge handles it alot better, and running a 400 Chevy? Questionable engine there! Weak!(400 Chevy) Now Hughes has the even bigger stroke. They almost give away the Chevy strokers, but our prices our getting better. Lets see, what do the new rules look like?

[titan]

there are spacers to put a 318/340 crank in a 360.made by callies.

[sanborn]

For the street, get all the cubic inches you can. If you want to race, the short stroke engines can be very potent----but be prepared to spend serious $$$(voice of experience, and I am old, baldheaded, cantankerous, and I like all engines too).

You may prefer Mopars, but engines are like women---you may prefer blondes, but you can have fun with brunettes and redheads too!

[rumblefish360]

Sorry, if I repeat something here, but comp cams I believe sells spacers for the 360 to use the 318/340 crank. (Not correcting titan)
MoPar sells destroker cranks for this. Or have moded journals?'s.

Reason being would be to fit into a race class limiting the cid.

[70AARCuda]

Originally Posted by titan

there are spacers to put a 318/340 crank in a 360.made by callies.

And they cost about 300 bucks for the spacers...and you have to have the main honed also...

Put the 4 in crank in it.....Stroke it...dont destroke it...

[Tarrbabe]

is that the only reason to de-stroke an engine is to fit into a class of racing such as TransAm. For street your better off with more cubes and even for Bracket racing your better off with more cubes.
BUT I DO LOVE THE SOUND OF A SMALL BLOCK TURNING A LOT OF RPM'S. But it cost a lot of money to keep it there.

Just thinking out loud.

[rumblefish360]

Originally Posted by 70AARCuda

And they cost about 300 bucks for the spacers...and you have to have the main honed also...

Put the 4 in crank in it.....Stroke it...dont destroke it...

I'm for that!

And by tarrbabe;

For street your better off with more cubes and even for Bracket racing your better off with more cubes.

I'm for that again! The added stroke gives torque and a lower RPM ceiling. You'll make peak HP at a lower RPM. Shift sooner and move the car easier with less stall.

[Ray Bell]

Don't know about that 4" bore... our experience with the Poly indicates that it's hard to get a block to bore safely for them...

And then the LA was a lighter casting again.

[72Challenger]

Ray, he's talking about his 360. 4" is the stock bore.

[Ray Bell]

Uh... yeah... I was aware of that, but some have said 'bore a 318 to 4"' and that's what I was referring to.

[rumblefish360]

Still, all that work to end up with only 343 cubes or 349 @ .030 overbore. Why bother? Lots-o-coin spent. Not well spent.

[Ray Bell]

Ahhh... some people spend a fortune to get an MG K3 on the road... delightful little six with a pump on the nose of its crank.

A huge 1100cc... that's 67cid... is that worth it?

Or the guy here who has spent a veritable lifetime restoring an MG Q, a single seater with 4-wheel independent suspension. Power unit? A 4-cyl with all of 45 cubes!

What's that good old American expression? Named a TV show after it... oh, yeah... different strokes for different folks...

[cageman]

Mancini sells crank spacers to put a 318 crank in a 360, So Dw, it is not impossible to do, like you said.

[dwc43]

Originally Posted by cageman

Mancini sells crank spacers to put a 318 crank in a 360, So Dw, it is not impossible to do, like you said.

Did not know they had a spacer for it. That's still a part that I would never even think about using in a high rpm app though. It would not last long that's for sure.

[cageman]

They have been using spacers in chevies and fords for years. Must be a problem area.

[TK]

Those bearing spacers have been around for ever, no problems there.

[sanborn]

The shorter stroke definitely yields less torque and is more difficult to perform on the street.

When the decision is made to use a short stroke in competition, you make a parallel decison to turn more RPM. In our chosen endeavor of competition, dirt Super Late Models, the RPM we use with a 3.305" crank is about 500-700 more than we would turn with a 3.800" crank. And gearing must be comparable.

The smaller engine is more touchy on gearing, driving and where you run on the track than the larger engine. And we are still searching for the right combination for the short stroke engine. But there are few sounds that compare to a short stroke engine coming down the straight @9000RPM---unless it's a long stroke engine @9000RPM(we don't have enough $$$ for that).

I truly think the best engine for our general use would be a 3.500" stroke. This would still give us a good RPM range, better torque and easier to drive. Anyone have a 3.500" crank, billet, 40 lb. that would be willing to donate to the cause? The rods/pistons to match would be nice too!

But for the street or if you are not willing to turn the extra RPM, stay with the longer stroke.

BTW, we thought a friend was bringing a prototype 375" P7 engine to our local track last weekend for testing. It is designed to run in the 9400RPM range. The engine builder wouldn't release the engine---yet! Hearing that thing coming down the straight would raise my blood pressure a few points---owning that thing would raise it even more!!!

[George G. Leverette]

Where are we going to legally use all of that horse power? Our community is blessed with the fastest streets in the world, do you beleive 40-60 MPH posted speed limits within city limits. Visited my son in Bellevue WA and was shocked with the 35 MPH rigidly enforced speed limits in the city. That's second gear stuff, why would anyone need 400 HP in that situation? When we say street driven, that indicates, senior citizens who move more slowly, school zones, children who chase balls into the street and around here people without drivers licenses or a comprehension of the english language. A sweet running 318 with a 4bbl and duals is plenty of power, remember you gotta stop that thing and the new 300s are stopping in 130 FT from 60 MPH and for safety sake that should be considered. We should check the reality and responsibility box on our comments. Magazine horse power is not real and sticking after market parts on a street driven will "not" produce the same results.

[B1owner]

Originally Posted by George G. Leverette

Where are we going to legally use all of that horse power? Our community is blessed with the fastest streets in the world, do you beleive 40-60 MPH posted speed limits within city limits. Visited my son in Bellevue WA and was shocked with the 35 MPH rigidly enforced speed limits in the city. That's second gear stuff, why would anyone need 400 HP in that situation? When we say street driven, that indicates, senior citizens who move more slowly, school zones, children who chase balls into the street and around here people without drivers licenses or a comprehension of the english language. A sweet running 318 with a 4bbl and duals is plenty of power, remember you gotta stop that thing and the new 300s are stopping in 130 FT from 60 MPH and for safety sake that should be considered. We should check the reality and responsibility box on our comments. Magazine horse power is not real and sticking after market parts on a street driven will "not" produce the same results.

Every post you make you sound like a pessimistic old fart.

[indy swinger]

Hey George r u the guy on the interstate passing lane doin 55 with ur left signal on for 20 miles? LOL............ just skidin ya!

[TK]

He has a point.........
Buuuuuuuut..................
If you are doing 30, and your back tires are doing 90, are you speeding?

[sanborn]

Gee, maybe he is talking about my post. I admit I do get carried away sometimes---but I do like to talk; since I can't do as much anymore.

But I did go through the same decision last year about my wife's "retirementmobile". We decide on the short stroke route. And I am still working on it---will get it done someday. Besides, when she decides to terriorize the streets, the car needs to be right---both go and whoa.

[TK]

From what I have seen from your posts, go will mean GO! LOL.

[Billydelrio]

I do believe that "the little old lady form Shelbyville" will have more than the factory rated horspower.

[sanborn]

Her engine won't be that radical, just a 289 w/2x4s, nice heads, a little cam, nice headers, MSD, balanced, etc. I really need to post photos--even though it's not a Mopar.

Me? I am the senior citizen type that George refers to---drive at 35 MPH. A flathead V8(or straight six if I had one) is more my speed. I just still get my jollys hearing a car coming down the straight @9000.

We just like to race Mopars!