I aquired a chev 454 2 bolt main block,thatI would like to get 496 cubes. should i stroke it or bore it or both.What would be the best method of acheiving this goal.

You will have to do both, 60 over with stock stroke is 468 cubes.

a friend of mine has a 496 and i believe he said it has a .125 overbore and it has a custom crank. what stroke the crank is, i can't remember.
i also found a place that says you can get a 496 with a 4.250" bore and a 4.37" stroke crank with 6.135" rods. i'm not sure about that combo. i found this combo at www.mortec.com (http://www.mortec.com)
check it out for yourself.
later,
bruce

JLF454

I believe pdq67 is building a 496. I'm sure he would be able to fill you in on all the details. Hope you don't mind me volunteering your services pdq... http://www.camaros.net/forum/biggrin.gif

Mark

You would need a bore of 4.44 to get to 496 with existing stroke. Or 4.30 bore and 4.25 stroke would get you 496. 30 over and 4.25 will give you 489, speed o motive sells that in a kit form.

I asked the question about biggest stroke in a 454, and got that it was 4.25. Unless you want to pay big machining costs or big money with rods.

They said the difference you would save you could get a bowtie block and not have them problems.

Boy, I thought nobody would ever ask.

Mine is a .060" over 454 '75 truck block with a Lunati Stock GM welded 1/4" stroke crank.

I used the truck rods because when Lunati's told me that "oh, by the way, you will need to use 1/4" longer rods", I had my head up my "cylinder" and it went right over it.
Plus, I'm kinda "frugal", Ha, Ha!!!

Everything worked out fine though because the cost of turning the counter weights on the stock welded GM crank, and balancing with heavi-metal was slightly less than the custom rods at that time (summer of '95).

Of course, my rod/stroke ratio is a little low, but what the hey, I'm not going to run the sucker much above 5500rpm. I don't have to because the Comp Cam 282S solid I'm using puts my t at 4500 and my hp at 5500rpm. (580lb-ft and 550hp simulated with Dyno2000).

I also am using Merlin oval port cast-iron heads and matching Ross forged pistons and shim head gaskets to get about a 9.8 to 1 CR.

Next, is a Holley Strip Dominator single plane and a 3310-2 750 cfm holley carb. Finally, a set of small heddman 1 3/4" four tube headers.

All this goes in front of an M-20 and 3.31 gears in my 12 bolt. Car is '67 SS/RS

A simulation run using Drag gives something like high 10's above 125mph for the quarter if I can hook. With a 3250 weight, I think.

If I had everything to do over again, I would probably have saved my money and bought a Merlin block that would bore 4.70"+ and use a 4 3/8" or 4 1/2" crank and came out with a sleeper in the low 600 cubic inch range. Put 360/400cc+ aluminum heads on it with 2.40"/2.50"intakes and 2.00" exhausts or whatever the largest I could install then go with a 240/245 duration cam.

Otherwise, I woulda bought a Speed-O-Motive balanced forged rotating assembly spec'ed the way I built mine. Canfield bb rectangular aluminum heads in the 300cc range with 2.25" or 2.30" intakes and 1.90" or 1.94" valves and set up to use a custom Comp Cams solid street roller like a 280 intake/288 exhaust, 110 LCA/106 ICA, with max lift range. Then through on an 850cfm Holley and 1.875 headers.

Please pardon me while I dream. Hope all This helps. pdq67

Knew you'd come through pdq! Maybe some day I'll make it over to introduce myself and check out that beast motor.

Mark

mbrekke,

Any time, any time!! I've been toooo lazy to just come over and introduce myself. pdq67

Hey pdq67,


What block are you using, Mark or Gen?
I e-mailed Speed o motive and they said on my Mark block I don't have to notch the block if I use steel rods. They did say I have to notch the oilpan rail. What did you have to do for clearance?

'75 truck block. And yes the 1/4" arm fit without a hassle with the stock truck rods.

I'm not too sure that a 3/8" crank wouldn't fit touble free. Just make sure that the counterweights clear the pistons with the stock length rods,

And don't forget to CLEAN your crank REAL GOOD in the oil passages before assembly because, chances are it will be full of glass beads, steel shot, grinding dust or whatever. pdq67

bruce69camaro,

I missed the Mortec post. Looks like a .060" over 502 with the new 4.37" crank will give you 563 if I "done did" my math right. But should probably put some .400" longer rods in the "beast". Is this a winner or what???

Allen M, it's a '75 Mark IV truck block. pdq67