Big inch small blocks?
 

I see World is making a small block with 4+ inch bores. Has anybody used one of these for a marine application? They have crate small blocks up to 454 ci. I would want a lower C/R and different cam, Iconnel etc. Any builders have any experience with these. I was told Dart also has a raised cam small block. I started a thread like this the other day,but I think it was lost to site maintenance. Thanks Iggy and Ed Cozze for the replies. Doug

Re: Big inch small blocks?
 

I would like to hear about that too. Good question.

Re: Big inch small blocks?
 

Id love to see some big inch smallies in a boat.......Id like to see if they would 2-300hrs even more...........doug

Re: Big inch small blocks?
 

We built a 434 ci small block it had a 4.000 stroke crank and a set of World Products Iron heads with a Hyd roller cam the engine made 525Hp at 5300 on pump gas. The problem we had back then was the stock block needed so much clearance on the oil pan rail you went into the water jackets on the bottom of the cylinders. The new Dart blocks have more clearance and have a lot thicker cylinder wall to stay round for a better ring seal. Also we had to use a camshaft ground on a small base circle so the top of the connecting rod bolts would clear the camshaft lobes using the 6" long rods. With the raised camshaft
you will have more clearance and you can use the standard cam core so the camshaft will not flex and you will have more accurate cam timing.

Re: Big inch small blocks?
 

My post was about the Olds Rocket blocks from about 8 to 10 years ago. They have the cam higher in the block to clear the stroker cranks. Most of the parts needed were expensive aftermarket stuff that had to be special-ordered back then and really expensive. I think what we ended up with was a 540 inch small block.
I haven't heard much about those engines in years. I think Paul Pfaff did them.

Re: Big inch small blocks?
 

A 540 Sbc?

Re: Big inch small blocks?
 

Eagle is making stroker cranks that have been lightened and connecting rods that are clearanced for the cam lobes.

Re: Big inch small blocks?
 

yep.

Re: Big inch small blocks?
 

457 is the biggest small block Rocket Ive ever heard of. That 540 must have been something.

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Why screw around with a SBC when the BBC is so available????

Re: Big inch small blocks?
 

Power to weight ratio and size mostly.

Re: Big inch small blocks?
 

I guess in a 22' single or a 28-32' twin the weight would help some. I still think the weight of a good 502 is only about 300lbs more and will make up for it in torque.

Leave all the Fat women on the dock!!!!!! Just kidding!

Re: Big inch small blocks?
 

Cop to speeding motorist: "Have you been drinking?"

Guy says: "Do you see any fat chicks with me?"

Re: Big inch small blocks?
 

It's tough to get compression down in those SBC combinatons.

Not that it is absolutely necessary but I had a guy that needed to run 87 octane and the custom piston while maintaining a decent rod stroke ratio was tough.

They are pretty much BBC type bore and stroke with a lot shorter rod. And WAY smaller chambers.

Re: Big inch small blocks?
 

I used a tall deck Rocket Block on my 436ci, 4.125" rods, 4" stroke, 8.45cr. and a little boost from a M3 Procharger. :D

Re: Big inch small blocks?
 

I since learned I was wrong about building out the Rocket blocks to 540.
They were 482s when we finished them.
Sorry for the error. Time clouds the memory sometimes.

Re: Big inch small blocks?
 

Sorry, We seem to have lost all of yesterdays posts after about 1:00 PM. Thanks Laz and Bob and many others for great posts. This 434 number seems to come up a lot. Tyler said he used a 4" stroke. Would that make the engine almost square 4x4? Does anybody think it would be possible to make a civilized 500 hp. ie: good idle, keep the rpm down and 87 would be nice. Laz and RMB, I like the idea of the aluminum 427 but then I have to go to closed cooling. I don't want to worry if I run into some salt water. Is there a process for coating water passages in aluminum blocks like they do for heads? Laz, pic's are always a good thing. Doug

Re: Big inch small blocks?
 

I would think that you could make 500 hp with a stock 400 block equipped with good rotating assy.and some good heads. 421 cu is feasible without a lot of grinding 3.875" stroke crank.4.155" bore .I have ran 400 blocks for years .I doubt that I am making 500 hp but somewhere in the 400+hp.I have a 400 block.BRC 3.750" stroke Crank,5.7" Oliver Rods and run a J&E sportsman off the shelf piston 9.3 to 1 comp. Ported Dart Pro1's 200 cc intake runners . Victor Jr intake . .625" lift solid roller ( I can't remember duration been too long ago) Holley 780 cfm carb /Gill Exhaust

Rob

Re: Big inch small blocks?
 

Heck if all your looking for is 500Hp in small block form anyone should be able to build that out of any 400 block even with Iron heads with no problem I finished a 4.155 bore 3.750 stroke 406 last week with TFS KENNY DUTWEILER heads cam was 245 @.050 intake 252 Exhaust .535 .565 lift flat tops 68cc heads Edelbrock VIC JR 750 hp holley idle at 850 rpm and made 559HP at 6000rpm from 3000 to 4500 was over 500ft lbs I forgot the cam was a flat tappet Hyd. The only work out of the ordinary was the porting of the heads and intake which we did in house. Good luck Laz

Re: Big inch small blocks?
 

Laz- was this motor for a boat???............doug

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Doug it's actually for a ski boat for a friend in Lake Okeechobee.

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Laz, A 500+ hp ski boat, I don't think I could hang on to that rope. Doug

Re: Big inch small blocks?
 

I was at the dyno shop last weekend and they had a fuelie small block with nitros and a supercharger that made over 2000hp. It looked trick and I am sure it made some serious power. They also build radical big cube motors (706) with over 3000hp that go in pro stock drag cars. Very impressive high dollar stuff. The motor they were dynoing was a friend of mines. 540 with a 1071 blower making 1066hp at 6200rpm. Not to shabby either. This shop is near Sparatanburg, SC

Re: Big inch small blocks?
 

someone around here is running a 434 that i heard pegged the needle at 1000+, though i don't believe he runs that power on a regular basis that i know of, runnin in an 18 foot boat... :drink:

so just how MUCH duration can you get away with a big inch sbc and aftermarket WATER cooled exhaust that isn't dumping right at the tips?

Root

Re: Big inch small blocks?
 

My 408" has Comp Cams solid roller .625 int. .631 ex. [email protected] 112 cl . I run Gil Wet exhaust that exits below the water line.Never any reversion with this setup.

Rob

Re: Big inch small blocks?
 

Does anybody remember the 30' SuperBoat RC Marine?? Boat ran awesome with small blocks. Beat everything in its class for many years. Who built those motors?

Re: Big inch small blocks?
 

TTT :drink: I'd like to know who, and what was in them???