454? [Archive] - Nova Tech

: 454?


72novaguy
Aug 14th, 09, 03:05 PM
can anyone plz tell me how big of a cam you can put into a 87 454 with stock heads and how much you can bore it and how many cid would it be thanks

Fat Rat
Aug 14th, 09, 03:26 PM
Well it all depends on what you are going to use it for as to how big of a cam you need to run. Normaly you can bore them .030 to .060 with no problems know for CU this is how you get CU ( Bore X Bore X Stroke X .7854 X 8 )
(4.310 X 4.310 X 4.25 X 1/4 pie .7854 X number of cylinders 8 = 496 cu

454cu .060 over with 1/4 stroke = 496cu

Big Dave
Aug 14th, 09, 03:48 PM
A 0.030 inch over bored 454 with a stock 4.00 inch crank yields 460 cid. A 0.060 inch over bored 454 with a stock crank yields 467 cid. when you stroke it out with a longer than stock 4.25" crank (and pistons because the pin moves up) you get 489 cubes with a 0.030" over bore and 496 with a 0.060" over bore.

The "peanut" round port heads on your current 454 are great for a tow truck or RV, but will fall flat on their face above 4,500 RPM as they were designed for a truck with 10,000 GVW or more. To realize any performance potential you will need to consider the PASS Oval port heads off of a 1970 to '74 car or truck (unless you are going with the 496 as at about 500 cubes the HiPerf rectangular port head is manageable on the street).

Because with any over bore of any kind you are buying new pistons, you can have the pistons fly cut for a "bottom of the page" cam by the machinist doing the overbore. That way their is no restriction other than having the car actually be drivable in your cam choice.

Big Dave

72novaguy
Aug 14th, 09, 03:53 PM
im goin all out drag racing wit this motor and how would i go about makin a 511 bbc

Big Dave
Aug 14th, 09, 04:06 PM
By buying a Dart Big 'M' 4.600" bore block a Callies crank Howard rods and JE pistons then decide what RPM you want to trap the motor at, and the amount of power you want to select your cam and heads.

A Mark IV 1987 two bolt main BBC with a decent set of AFR or Brodix heads will pump out about 600 horse which is about all the block will handle reliably unless you are changing everything inside over to forged parts.

Big Dave

Fat Rat
Aug 14th, 09, 04:22 PM
By buying a Dart Big 'M' 4.600" bore block a Callies crank Howard rods and JE pistons then decide what RPM you want to trap the motor at, and the amount of power you want to select your cam and heads.

A Mark IV 1987 two bolt main BBC with a decent set of AFR or Brodix heads will pump out about 600 horse which is about all the block will handle reliably unless you are changing everything inside over to forged parts.

Big Dave



If you are going to buy a Dart block I would take it out to 632 cu in my book cu is free HP.

Some stock block will take a .125 Bore and still have enough meat to not make the cylinder wall egg shape. That will give you a 511cu 454 with a .125 over bore with a 4.25 (1/4) inch stroke= 511cu.

72novaguy
Aug 14th, 09, 04:30 PM
will a 87 454 beable to be bored .125? and a stock 454 has a 4.000 stroke rite?

Big Dave
Aug 14th, 09, 04:44 PM
will a 87 454 beable to be bored .125? and a stock 454 has a 4.000 stroke rite?

You can cut it that far (I give you my permission) BUT there is a possibility you will hit water as the factory recommends only a 0.030" overbore. Before you bore the cylinders out have your machinist sonic test the block to see how straight the casting was (there could be core shift). Additionally the thinner the cylinder walls the more heat leaks out of the cylinder so it not only runs hotter it will be down on power compared to a cast 4.500" bore block.

Yes a 454 and 502 have a 4.00" crank throw (3.76" for the 396-427). Your block will accept up to a 4.250" stroke with only some grinding. Go beyond that and you will be better off with another block. A 632 for example requires a tall deck truck block or an aftermarket block (either way it is a 4.600" bore with a 4.750" stroke) and the largest displacement standard deck height block is 598cid (I have a 582 4.600" bore by a 4.375" stroke in my case); a 598 requires a 4.6" x 4.5" if you can stroke it out that far as you need a BowTie block or a Gen VI block to handle the stroke).

You will need to do some reading before you spend any more money as the only thing you can use in a drag motor from your current 454 is the bare two bolt block which will still require more money to get it ready to be competitive. (Of course you can run what you have now but be prepared to loose every race; which gets frustrating).

Big Dave

72novaguy
Aug 14th, 09, 04:49 PM
well i pland on stripping the motor down and putting beter pistons and stuff like that i was jw if it would be worth it to bore it and would it be ok to use the stock heads and go get machine work done to them and diff springs and valves? and wats the biggest cam i can fit?

Big Dave
Aug 14th, 09, 04:58 PM
Every BBC Mark IV cam ground will fit inside your block. Whether a given cam is a good choice for you I have no idea.

The post 1974 BBC heads are boat anchors (too big and heavy to use as a door stop). Like I said you can spend your money anywhere you want, but if you expect to win at racing I suggest you spend it more wisely.

Big Dave

72novaguy
Aug 14th, 09, 05:22 PM
i havnt spent any money yet and i know it will fit in the block im talkin about how big of a cam will the heads hold

Big Dave
Aug 14th, 09, 07:26 PM
Not much more than the stock lift as your pistons are dished but the stock cam didn't have much in terms of lift and a 1987 cam will be set up for TBI as 1986 was the last year for a carburetor (if it has a cast iron QuadraJet low rise on it now that is the factory manifold for a TBI which used a water heated spacer under the injector).

From CompCams I would recommend cam part number 11-670-4 (Grind number N+LS6) which has specs of 229/236 duration at 0.050" lift and valve lift of 0.530"/0.524" with an LSA 112. It is supposed to give an exhaust sound of the old LS-6 454 450 horse motor, which was originally a solid tappet lifter motor. This won't be a race cam but it will make a lot more than your existing TBI cam would, even though your heads will never be able to take advantage of the 6,200 RPM red line. You will have to verify you have clearance between the piston and the valve. Increasing the duration from the stock 180 or so has bumped the RPM range up more than the peanut heads can support, but to race you need to move the RPM range up to improve the amount of power the engine makes per second.

Big Dave

Fat Rat
Aug 14th, 09, 08:12 PM
I would suggest this comp cams p/n http://www.summitracing.com/parts/CCA-11-250-3/
I ran this cam in my 1966 Chevelle all steel it weighted in at 3900lbs with a 10" slick with stock chassis on 93 octange it ran 7.30's in the 1/8 with a 4.56 gear 468 BBC with closed chamber heades.

Fat Rat
Aug 14th, 09, 08:20 PM
Now on my full race Nova I ran a p/n http://www.summitracing.com/parts/CCA-11-607-5/ with 12.5:1 comp it ran 6.20's in the 1/8 with a 5.38 gear 33x17x15 slicks.

72novaguy
Aug 18th, 09, 10:02 AM
wat can you do to the stock heads to make them a little bit better?

Big Dave
Aug 18th, 09, 10:14 AM
That depends upon the casting numbers of the heads if they are a 10114156 or a 10141279 casting number ship them to Japan and hope there is unough metal in the heads to make you a new Honda as they are 'peanut' sized round port heads that are only good for towing your race car to the track. What do you have to work with?

Big Dave