Why would U ? Seen this twice on ebay .. 454 destroked To a 433 ci . Thanks

Maybe some guy's want a modified 427, that's all??

They do wind faster b/c of the shorter stroke if this is what the motor is being made for?

pdq67

THATS NOT A DESTROKED 454, IT'S A 30 OVER 427,RACED THAT SETUP FOR YEARS ! ROB...

they probably call it a destroked 454 because the block was from a 454

Just because nobodyelse spelled it out.

A 396 has the same stroke as a 427, and a 427 has the same bore as a 454,
so a 396 crank in a 454 block = 427.

Originally posted by Thad:
Just because nobodyelse spelled it out.

A 396 has the same stroke as a 427, and a 427 has the same bore as a 454,
so a 396 crank in a 454 block = 427. ...or a 427 crank in a 454 is a 427 ;)

Or, a 366 crank in a LS7 block @ +.060"= 439" tongue.gif

Soo it would end up being a high reving BB . Kool graemlins/thumbsup.gif Ya the guy said its a 454 block wit a 427 crank . Thanks guyz

Originally posted by Jason Shepp:
67 Chevelle SS
402 60 over
270H comp camJason,

Have you got any times on your combo? The Comp 270 is a favorite cam of mine so I'm wondering what people have been able to do with it.

Rod

If you want an even shorter stroke the 348 and 409 cranks can be adapted for a real high winder. :eek:

Originally posted by dyno jonn:
If you want an even shorter stroke the 348 and 409 cranks can be adapted for a real high winder. :eek: What was the stock stroke of a 348/409?

I'm currently running a 3.600" stroke crank in a 4.280" bore 427 block. You might think it is, but it really isn't a real high winder. I shift at 6800, might bump up to 7200-7500 this coming season. RPM has alot to do with head/cam selection as well.

Todd, by the looks of things around here, shifting at 6800 might be considered "high winding", although I tend to agree that 7200-7500 has always meant high winding to me, both mouse and rat ( old LT1 and L88 ).

You be a high winder 'round here!

Rmchevelle , no I dont , had many set backs last summer with car :( . Thanks for the input guyz !

Gene,

Just like a street cars definition, I guess high winding is quite subjective. To me, 8000+ rpm is high ;) :D .

Jason,
Look at my sig. I am running 453 cubes, but with a 396/427 stroke. If I had a 4" stroke, I think it would be too much torque off of the line for my M-20, so the combination works for me. It started out as a 454, but I "de-stroked" it, basically because of the parts I had available at the time. I can use the block for a 454 if I want because it has the reliefs at the bottom of the bores for a 4" stroke.

10secBu.. I'm with you 8200 was comman for my SB, shift cable came loose on a pass, no 3rd gear, was hell bent on drivin it thru.. went to 9300 lost some ET and MPH .. but it worked .. building a 511 now ( 4.375 x 4.250 ) and I plan on spinning it to 7800

Epistuff
Tech Team


posted 12-27-2003 04:53 PM
--------------------------------------------------------------------------------
Jason,
Look at my sig. I am running 453 cubes, but with a 396/427 stroke. If I had a 4" stroke, I think it would be too much torque off of the line for my M-20, so the combination works for me. It started out as a 454, but I "de-stroked" it, basically because of the parts I had available at the time. I can use the block for a 454 if I want because it has the reliefs at the bottom of the bores for a 4" stroke.

-------------------- wow! bored .125, I didn't know you could take a 454 block out that far.

A 348 "W" motor has a 3.25" crank and a 409 "W" motor has a 3.5" crank!!

Yes, way back when before 500" motors, the little short stroked, 10,000rpm, BB suckers ruled the strip!!

I don't know what the cube's really ended up being for them but do know they were something as far as high revving!!

pdq67

Originally posted by 10secBu:
What was the stock stroke of a 348/409?The 348 had a 3.25 stroke, the 409 had a 3.50 stroke. The 348/409 cranks are not exactly drop in, but the bore spacing is the same as a big block. It takes spacers for the bearings and the 348/409 crank snout is smaller in diameter.
It's not a big deal for a pro crank company to make them fit the big block.

Back in the early 70's at National Trail Raceway in Ohio there was a big block based NHRA Modified Production Nova running in a class where only a small block would fit. The thing wound up like a 327 with the short stroke and the big square port heads.

Do they actually make these spacers to put a 348, or a 409 crank into a big block? Wouldn't you also have to have custom rods? How much would it cost to have a Wide block crank modded to fit a big block?

The 348/409 crank in the BBC was used alot as PDQ said prior to NHRA adopting the 500 inch rule...before that they ran a weight break system that was never really fair to all competitors... if you ran X CID your car had to be a certin weight and if you ran Y CID your car had to weigh a different weight.... and sometime they would change the rules in mid season...sometimes from race to race....The Ford guys would gain and advantage and then start winning all the races and then they change it and then the Chevy guys would dominate...

This allowed the Chevy guys to use a large bore relitive to stroke and spin the BBC into the 11,000 plus range... So these guys were trying anything regardless of cost to compete....Hi RPM power rules in Pro Stock... not torquey long stroke engine.

Fortunatly NHRA finially had the kahoneys to say the heck with it and make everyone run the same min weight and just have a 500 CID limit....and who ever wins or dominates wins .

The old "W" motor's rods are two lengths, one the same as a stock BB and the other slightly shorter.

The book I have gotten some info on this from mentions a 365" motor that was built way back then that made more then 750hp and ran up to about 10,000rpm.

I did a ratio caculating thing way back when I put my .060" over 409 in my car where I compared a SB to the "W" motor. I forget whether I used 283 vs a 348 or or 409 or a 327 vs a 409??? But it appeared that the "W" motor was almost indentically a sized up SB whichever one was used!!

pdq67

409,,,,,,,,a 350 (well, almost, 3.5 vs of 3.48 for the purists) with a 4.312 bore, rat rod bearings & it's own mains :D

I am doing a 452 "W" project for a customer which uses a 396/427 crank cut for the "W" mains & a "wee bit" of counterweight trimming
Hey,,,it's his money :D

A seemingly crude by high tech standards method of doing the crank swap was to put main bearings into the 396/427 block, then align bore the 396/427 bearings to fit the outside bearing diameter of the 348 main bearings. The bearing lock grooves had to be cut by hand, and the thrust bearing must also be modified so one fits over the other. The 348/409 crank snout is like a small block, so the snout was either welded up and ground to fit a BB damper or the front crank seal area of a 348/409 timing cover was grafted into a BB timing cover and a W motor damper was used. Special rods weren't a big deal since new pistons had to be used and the pin location would be put where it needed to be.

Ok, so how do you get a 348/409 crank into a 454/427/396 block. I take it there is no spacers. And it sounds like you would need custom rods. It sounds like the only real drawback would be weight. You would get smallblock cid with big block weight... Is the performance of this combo worth the extra weight?

Dyno jonn just told you.. And that's how they dropped the 350 crank into the 400 blocks before the bearing spacers were around.

And I think they even did it twice by using a 400 bearing, then a 350 bearing and finally a 283 bearing to drop a small journal 283/302 or 327 crank into a 400!!!

I forgot to mention that the old stock, 430" BB race motor used a 3.47" crank and a 4.44" bore!!

There weren't many made and probably are about as rare as the 427" "W" motor is!!!

I figure an aftermarket block to 4.625" bore x 3.76" stock crank = 505" motor would be about the cheapest way to make one of the high-revving small block type big block motors... It's almost the same as a Z-28 motor if you would want to add a longer custom rod..

pdq67

I didn't see dyno johon's post before I replied, I guess it took my longer to write mine, and his came up first. It sounds like the crank swap is more work than it is worth. Although it sounds coolm and would definitely be different, it doesn't sound like it would be worth it. The whole 283/327 crank into a 400 block sounds like it could be fun also, but still alot of work.