View Full Version : max ci from 454 block?


Larry79z28
08-16-2005, 07:38:00 PM
over the weekend while at a car show, a guy parked next to me in a very healthy sounding 67 camaro. Once he got done wiping his car down, I proceded to ask him what he had done to his 454? He went on to say it really wasn't a 454 but a 548 with 13:1 compression that he drove about 60 miles one way he claimed this was out of a production 454 block. I really don't know a whole lot about big blocks but it seems like a lot of cubes to stretch out of a production block. I did however see a kit for a 548ci in the Doug Herbert book?

muscl car
08-16-2005, 08:41:00 PM
<font face="Arial,Verdana" size="2">Originally posted by Larry79z28:
over the weekend while at a car show, a guy parked next to me in a very healthy sounding 67 camaro. Once he got done wiping his car down, I proceded to ask him what he had done to his 454? He went on to say it really wasn't a 454 but a 548 with 13:1 compression that he drove about 60 miles one way he claimed this was out of a production 454 block. I really don't know a whole lot about big blocks but it seems like a lot of cubes to stretch out of a production block. I did however see a kit for a 548ci in the Doug Herbert book?</font>

scott shafiroff racing engines ultra street and saturday night special engines:

540 /675HP BBC

http://www.shafiroff.com/540_675_engine.asp

big dog series 598/755 HP BBC

http://www.shafiroff.com/598_755_engine.asp

------------------
1972 chevy camaro ss
425HP 350sbc old school build-up

restification in progress 70's baldwin motion NHRA gasser with old school day2 parts
------------------

if it's to loud your to old

[This message has been edited by muscl car (edited August 16, 2005).]

badazz81z28
08-16-2005, 10:41:00 PM
Most 454 blocks will max out at 496. The after market World Merlin III blocks can be punched pass 600ci

jakeshoe
08-17-2005, 12:39:00 AM
It's fairly eassy to get 520+ cubes from a stock production 454 block...

535+ is possible..

1981coupe400ci
08-17-2005, 01:17:00 AM
bore and stroke to the max http://www.nastyz28.com/ubb/wink.gif

Grumpy 427
08-17-2005, 02:26:00 AM
I am looking to build a 496, i have priced out an eagle rotating kit with SRP pistons. Will be 10.69-1 compression with my 110 CC heads. .060 over 454, with a 4.25 stroke crank and a 6.385 rod.

sinner4
08-17-2005, 03:14:00 AM
A production "TALL DECK" block, is the key word. A "TRUCK" block. Not a pick up truck block. I think the old school was a 572 cid. With all the new cranks, who knows what the hell. A 510cid was a "SHORT DECK" with a stroker crank with some grinding to the block to clear the crank...

PetieG383
08-17-2005, 11:47:00 AM
Flatlanderracing.com offers a 524ci crank kit for 454 blocks.

badazz81z28
08-17-2005, 09:40:00 PM
<font face="Arial,Verdana" size="2">Originally posted by PetieG383:
Flatlanderracing.com offers a 524ci crank kit for 454 blocks. </font>

Is that just stroke increase or bore too? I recently had 2 454s sonic checked and neither one could safely go .100 over

pdq67
08-17-2005, 11:00:00 PM
I figure this is about the max. on a stock, early '70's/'80's P/U truck standard deck height, 454 block.

4.350" b x 4.375" s = 520". Should drop right in, imho..

AND yes, a tall deck block can go upwards to 550"+!! with the same .100" or .125" overbore!!

pdq67

jakeshoe
08-17-2005, 11:32:00 PM
You could stroke a stock 454 block to 4.5" stroke.
A 4.250 fits with zero block clearancing, even with stock rods with zero clearancing done to the rods. Nothing was even close on my block.
Most 454 blocks will go .100". Some will go .125".

A 454 should swallow a 4.375 with an aftermarket rod.
So some clearancing and using stroker profile rods would fit a 4.5 crank in a stock short deck block, you would have the oin in the oil ring like a 6" rod 3.75 SBC...

I wouldn't hesitate to build a 4.375 stroke motor from a 454 block, as easy as the 4.25 stroke was.
The rotating assembly would only be moving 1/16" closer to the block so would still require minimum if any clearancing...

n2omichael
08-18-2005, 01:29:00 AM
The most you are gonna go with a "true" production block [short deck] is around 500 inches, I think what might be confusing some people is that a "bow tie" block is a "production" block, but, was never put in any car from the factory, its actually a "race" block with a GM part number, its available in short and tall versions, and they aren't cheap [new], and are HEAVY!.

Anything over .060 over [468 with a stock crank, 496 with a 4.25 crank] and you are gonna need to cement the block, I have heard people claim to have gone .100 over on a "stock" block and not fill it, but, the walls are too thin, and you never get a good ring seal if you dont, in my opinion at least.

Michael

jakeshoe
08-18-2005, 01:46:00 AM
I'm not talking about a Bowtie block.

I have sleeved a .100 over 454 block back to .100 over, boring for a sleeve did not hit water....
If you can sleeve a block that is .100 over and not hit water, the walls are plenty thick enough...

A .060 over block with a 4.375 stroke is 510 cubes. No problem to do, very little if any clearancing necessary to the block, no more than a normal overbore.

Make it a 4.500 stroke, and you have 525 cubes with a .060 overbore. Same motor .100 over is 535 cubes...
Still very doable.
I've played with 580 cubes on a short deck Bowtie block with a .4530 bore..., 1400+ HP alcohol injected blown BBC. 12,500 rpm every weekend.

badazz81z28
08-18-2005, 05:44:00 AM
Looks like World products has a different opinion

http://www.worldcastings.com/merlinIIIbb.shtml

n2omichael
08-18-2005, 05:56:00 AM
I would be VERY interested to see how you make a blown bowtie based motor that is swinging a 4.5 inch stroke crank "live" at over 12,500 RPM every weekend, considering most Hemi based Pro Mod motors are down several 1000 rpm less than that, and most 500 inch naturally aspirated NHRA Pro Stock motors turn "only" 13K? or are you claiming thats blower rpm? [at 30% over you would be turning the motor around 8800 rpm] which in my opinion [no offense intended] is a little more reasonable

Michael

jakeshoe
08-18-2005, 01:01:00 PM
<font face="Arial,Verdana" size="2">Originally posted by badazz81z28:
Looks like World products has a different opinion

http://www.worldcastings.com/merlinIIIbb.shtml</font>


Surprise, surprise... An advertisement that makes claims to sell their product...
Did you read the part at the bottom right that says a stock block needs clearance work with a 4.250 and LOTs of grinding for a 4.375?
I can tell you from personal experience that that is definitely not true. And there are several members here with 4.250 stroek blocks that can verify they had to do ZERO clearancing on the block, and still had plenty of room...

Is a Merlin block thicker than stock, sure.. And most racers prefer a Dart block...Might want to do some research on the reasons why...

The 580 cube motor in question by N20 is owned by Joe Cypher. www.rangermotorsports.com. (http://www.rangermotorsports.com.)
Next time you get a chance to go to a monster truck competition that he will be at, see if there is anyway you can take a look at the telltale tach after a run. It's not blower rpm....

pdq67
08-18-2005, 07:41:00 PM
All I'm gonna say is if my 496 doesn't give me enough 3rd gear seat of the pants at 70 mph FEEL that I want, I will probably build a 588" motor using a standard deck height Dart or Merlin III block!!

4.625" b x 4.375" s = 588" AND I will use 6.450" long custom rods and JE pistons...

Plus a 350 to 360 cc rect port big valve head!!

CAN you say "A great big "Tow-Truck" motor"!!!....

And I don't think a 4.5" crank would fit in a standard deck height block AND I talked to Lunati's, HTC, The Crankshaft place on Tillman street in Memphis, Shafiroff(Sp?) and a couple of other places and they all said, NO!!

NOT PRACTICAL AT ALL... So what gives??

pdq67

jakeshoe
08-18-2005, 08:27:00 PM
Paul,
IIRC you have a 4.250 stroke in a stock block, and it required zero clearancing for the block, correct?
You had problems because you used a stroker crank with a stock length rod, so the pistons hit the counterweights.

So a 4.250 clears with zero block clearancing.
A 4.500 stroke, increases stroke .250 inch. 1/4"..

That is only throwing the rod journals, rods, etc. 1/8" closer to the block at any given spot. I had at least 1/16" clearance everywhere with zero grinding.
So would not have had to grind more than 1/8". I've built 383's that needed more than 1/8" clearancing in spots...and that was not using a stroker profiled rod.

The main problem with a 4.500 stroke in a stock block is the pin is going to be up in the piston quite a bit. Very short pin height.
A 9.800 deck BBC with a 4.500 stroke, and a 6.535 rod will need a pin height of 1.015. Not super unusual these days.

I've assembled 421cid SBC's with a 3.875 stroke and 6" rod that have a 1.0875 pin height...on a stock block.

I'm personally not a fan of the super short pin height and the resultant oil ring supports, but they seem to work OK.

I would prefer to build a super big cube BBC on a tall deck block because of that reason, but you CAN build 580 cubes from a short deck block (Bowtie or aftermarket) using a 4.530 bore, and 4.5 stroke. You COULD go bigger with a 4.600 bore on some blocks...

I would not hesitate to build a 525 motor from a 454 block using a 4.375 stroke.
Main reason to go with a 4.250 stroke is the low cost and common availability of the crankshafts.

pdq67
08-19-2005, 02:27:00 AM
True!!

AND gotcha guy..

Like I said, a 588"er is about the biggest I would build using a standard deck height block.

You are looking at a 604" motor with a 4.5" stroke!!

pdq67