I have never seen a Dart 4.5 bore spacing raised cam small block. I'm going to build a 453 - 471 ci 4.180 or 4.200 bore and 4.125 or 4.25 inch stroker N/A motor. For Bee Jay here on the forum. With him money is no object. Solid roller and AFR 245 cc heads

My question is: Have you done any of these blocks? my other question is lifter bore diameter. Should i have Dart just machine out the lifter bores to .875 or .904, or possibly the .937 Crane ultra pros ?

comp cams Elite Race Roller Lifters

Lifter Bore: .904"
Wheel Diameter: .820"

http://www.compcams.com/Products/CC-...Race%27-0.aspx

 

Does Bee Jay realize this?

 

Bee Jay ask me to build him a motor at my work. He might have to do a little overtime at work to pay for 6.250 Crower rods and custom forged 4.200 bore pistons. Like my 434 pistons from Wiseco were customs sold in sets of 10 for $1400 with pins, rings, and spiral locks.

His wife will also appreciate the $4500 dollar shaft rocker and special springs on the 245CC AFR heads.

The Iron block is near $4000 all machined. He might as well get aluminum for a couple thousand more

It might be approaching $16,000+ in parts

I've done a couple of $25,000 race motors, but they have titanium rods and valves. The billet cranks dry sumps......

 

What kind of power is he looking for?

 

With heads that flow 340+ cfm the cam could be fairly mild like 248/252 like my 434 solid roller. Just mid .600 lift. I'm thinking with over 450 ci 600 some foot pounds of TQ and something over 600 hp is very doable even setting the rev limiter at 6500 rpm because of the 4.25 stroker crank. I've been talking to the local shop that has expensive dyno software. I want to have max power peak right around 6000 rpm.

I want to run pump gas and keep the compression right around 11:1

With the raised big diameter cam you have to run a toothed belt timing setup. Some kind of a crank trigger distributerless ignition with a curve like my motor of 18 - 20 initial and all it at 3200 rpm of @ 32 degrees because of the fast burn heads.

 

Dang, I doubt I end up with more than $16K in my 427 BB (alum heads, solid roller, long rods, custom JE's...); "mild" ~550 HP target on pump-gas.

With the kind of TQ/HP projections you're aiming for, I'd be interested in what tires are being planned to increase Bee Jay's traction limitations, particularly for his AX'ing.

 

Bee Jay is a big man and needs the TQ

 

 

Why not just get an LSX454 for $9.5k? That would leave almost another $7k for upgradess

 

Can i interest him in building an all alumunum conventional headed RAT. 4.60 bore pick your stroke. No razamataz high dollar shaft systems needed.

This makes more sense to me but if your a die hard SBC person guess this is what you do.

 

The problem with putting in a bbc like a crate motor 572 ci is space and weight headers....................

 

Well i suspect at 472 cu. what your talking about already needs custom made atleast 1 7/8 headers $1500.00 stahl price. well that same $1500.00 would do the rat headers. All alumnum BBC is light. The 572 crate motors your talking about have an iron block thats around 280 lbs. Alumunum version drags about 120 lbs off. Its like SBC heads only save 34 lbs. but the aluminum BBC pull off 70 lbs of weight. He could build a 585 rat easy as pie cheaper. 472 is a maxed out over stressed SBC.

Its comical when you set your SBC bare block on the floor standing up on its belhousing flange. Then set your BBC beside it start inspecting main web thickness and everything else you can think up LOL.

If he buys a heavy aftermarket iron SBC block he will barely be any lighter to roughly the same weight then an all aluminum BBC so this does not make a good argument to me for any reason to do it.

I'm sure he will end up with a raised hood no matter what he does
and custom made headers for a rat will easly clear anything needed.

You can buy conventional BBC heads as cast no CNC work that will flow more air then the 245 AFR SBC can flow for less money with no need for exotic shaft system and you seem to be talking low rpms in your build plan. You won't need any $1400.00 pistons to make it all fit.

I'm sorry this just makes no sense to me but if he is just a SBC
lover go for it.

Now i sometimes talk about building a small cubic inch SBC just to do it make pretty good power with it per cubic inch not senseable for a street car. But i'm talking about very little money spent.

Your talking about huge dollars spent on a lesser engine for more money spent.

 

Hes not open to a 421 or 434? 600hp would be a cakewalk as you probably know.
Much less $

 

If your going with a 4.250 stroke you may want to go to 9.500 deck and with a 4.500 bore spacing block are those AFR's build for that bore spacing.

Also you will need a crankshaft for a 4.500 bores spacing block. You might as well go with a 55MM cam tunnel.

So far I have not machine a 4.500 bore spacing block but just machined an Iron Eacle block for a 4.200 bore and a 55MM cam and had the block set up for the DRCE-3 oiling.

.904 is pretty common for lifters now!!

 

Again why not just get a new LSX454 crate engine? It meets everything you stated:
620hp / 590 lb-ft torque ( as tested with the PT #19244033 Carb Intake )
Bore x Stroke 4.185" X 4.125"
11:1 Compression
Bowtie LSX Iron Block ( PT #19213964)
Camshaft - 236/246 Duration .635"/.635 Lift Hyd Roller
LSX-LS7 as cast Aluminum Heads ( PT #19201806)
Note: Standard 24/50 GMPP Crate engine warranty applies.

http://www.jegs.com/i/GM%20Performan...0002/-1?CT=999

Nothing exotic, easily available parts, proven combo and as I already stated, if he has a large budget then that still leaves thousands available for other parts (headers, brackets, induction, fuel system, etc.) Also note that the LSX numbers are with as cast heads so porting is still an option

 

It's reeeeallly hard not to think about building LS motors. Much better sealing, much easier to work on... higher efficiency, low cost for an *all* aluminum engine. What more could you want?

Not to mention the head flow numbers are INSANE, you'll only find better in a big block application.

 

I'm going to say this in joking SBC of any kind past or present make fantastic starter motors for BBC there just a little to bulky for the job.

4.84, 4.9, 5.0, 5.20 bore spacing. pick your deck height 9.8, 10.2, 10.6,11.0

SBC past or present your stuck with no more then 4.4, 4.5 bore spacing.

 

in full agreement with a couple of the more clever gents:

Instead of sbc constraints, why not LSX or BBC?

 

There is no doubt plenty of opinion in favor of other engine build-ups (mine included), but if Bee Jay wishes to take things this direction it is his money after all. Do post up as it progresses George.

 

LX you can come up with more deck height still stuck with small bore's. Have no doubt he will have plenty of power with what he is planning.