396 BBC. Nos

General engine tech -- Drag Racing to Circle Track

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Re: 396 BBC. Nos

Post by rebelrouser » Wed Dec 20, 2017 1:47 am

That level of performance is possible. With that much compression I would want a cam designed to take advantage of the NOS. A good NOS designed cam will keep from burning up the motor, but remember because of the way most NOS cams are designed, when not using the NOS it might be a dog. I had a buddy who purchased a pretty stout 66 nova with a 421 small block, 10.5 outlaw drag car, with a good shot of NOS it ran low 9's high 8's, without the NOS it only ran in the 11's I get a lot of guys wanting a street engine and they are always asking for a NOS cam so they can spray it sometime in the future, most of the time I can talk them out of it. I have built a few mud truck engines that ran classes with and without NOS, with same truck and same engine, and the cam design is hard to get good performance with out compromises and keep the engine together. I usually tell them which class do you want to win the most, and go from there.

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Re: 396 BBC. Nos

Post by Newold1 » Wed Dec 20, 2017 8:44 am

Keep in mind that even GM with stock 396's never put one out with 12.5 to 1 compression and 2 bolt main caps and a steel crank. If you have the time and money to redo this engine after it grenades you will probably find it would have been less expensive and more timely to either use a 4 bolt block for recap your block with 3 center billet caps. Their are also lots of inexpensive 7/16" dimple rod sets available that will help keep it together with those NOS shots.

You are obviously focused on an ET and speed with your car, but in my opinion you need to focus on staying together and you are going to ultimately be a lot happier and richer in the long run with a stronger block.

Don't buy this engine twice! Do it right to start!
The Older I Get, The Dumber I Get :wink:

67 Nova
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Location: Race City, CANADA

Re: 396 BBC. Nos

Post by 67 Nova » Mon Jan 15, 2018 9:58 am

rocketracer380 wrote:
Tue Dec 19, 2017 2:55 am
Here's my combo 396 .060 ,12:5 comp 2 bolt main studded steel crank 3/8 rods 680" 714" solid roller ported square ports closed chamber 4.56 's and 4500 stall 9" lookin for 10.50's on motor and 9.50"s on a big shot plate @3400#
Sure, why not? YEARS ago, back in '96 my was a all steel (ran no hood) '69 SS396 Nova. 12 bolt 4.56 gear with 29.5 X 9 tire, OEM multi-leaf with Lakewood cheapies 50/50 shocks rear, 90/10 shock with Moroso spring up front. I ran a M21 4 gear.

Motor is a standard bore 1972 402 4 bolt block. All internals were built to 1969 375Hp specs with stock crank and rods (ARP bolts though) and even TRW replacement 11.5-1 piston. Balanced the assembly. Cam was a comp .660 roller with cheapy lifters and pushrods. Heads were the 840 ported and port matched to Holley Strip Dom and a reworked 800 carb.

Best time was 10.47 ONCE as I was kicked out for no rollbar. That was the only 1/4 mile pass on the car at the track. Bunch of 1/8 mile stuff with a bunch of 6.6/6.7 times. Hell I went 7.01 on 7 cylinders and it bent the pushrod in the burnout box.

So with 20+year better technology, I don't see why not.

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