New build advice

Hey guys, I am looking for some guidance with a new build. The class is for our local "king of the street" class. We make a short 2 mile trip, line up and race heads up. Single power adder, 10.5" or unlimited radial tire. The car is an 89' fox coupe mustang. 2 speed transmission. Shooting for 2800# This car will also be bracket raced, but not the important goal. I think 8.50 to 8.80 consistent will be very competitive. There are a couple cars that run a bit faster but slow later in the rounds due to overheating ect. So, the block will be an eliminator block. Wet sump with a vacuum pump. What bore / stroke do you guys recommend? Between round maintenance time will be limited to 15-20 minutes so valvetrain is going to have to be stable and not be at a high consumable rate. My current thought is to try to keep it at or under 7500rpm's. I have a set of new P-51's. My plan is to send them off to someone with a good program or sell them and go to a set of A-heads. Obviously, with a stout valvetrain (Morel lifters, shaft rockers, ect.) No plans for what is going to top it off. Single or dual carb is open. I have an F1R procharger and nitrous kits. Out of simplicity and time, I think a 2800 pound car running high 8's should be able N/A, cutting loose of potential problems and heat. What is your thoughts? Thank you for any time you guys can give me to help out with the planning on this build.

NA on Alky if it's legal?

It's legal. As long as there is no maintenance required between rounds. I will have enough time to refuel, lash valves, check tire pressure and that is about it.

rollercam1 wrote:It's legal. As long as there is no maintenance required between rounds. I will have enough time to refuel, lash valves, check tire pressure and that is about it.

You get good parts on the valvetrain you shouldn't be setting lash between rounds

It should be a pre or post event thing.

Should just be checking tire pressure and fueling it

Must use carburetors? Injection not legal?

As far as rules, no nitro, one power adder, must be DOT legal, Exhaust must end 2" past rear of door minimum. Headlights, tail lights, wipers, Windshield (Glass) Car must meet current IHRA standards for speed / time. That's it. My initial thoughts are to build something in the 550-600 cubic inch range, 14:1 comp. Ported P-51's or an A head deal. Big single carb or dual carbs. Whatever it takes to feed it. Big ass radiator. Am I off target thinking it should make 850 to run the number? That means 1.45 to 1.65 hp per cube. I don't believe the P-51's will do it regardless of what I do to them. But, I have no experience with either the P-51's or the A-heads.

Unported P51s made 920 hp: https://www.429-460.com/t7463-572-cid-stock-kaase-p51-heads

(I think you're better off starting with A460s, but you already have the P51s)

The alky would help you keep it cool, but I'm not a fan of alky with carbs. If it was mine I'd peddle the P51's while they're fresh and stick the money into a set of A's.

windsor wrote:Unported P51s made 920 hp:  https://www.429-460.com/t7463-572-cid-stock-kaase-p51-heads

(I think you're better off starting with A460s, but you already have the P51s)

Blake made over a 1,000 horsepower with his P-51's.

 P-51's are not a good nitrous or supercharger head because the exhaust ports are to small regardless of how much they flow.

I would build a A460 headed, 528 with a 10-71 supercharger at only 9/1 compression ratio, using dual-quads and 10 pounds of boost.

It would run as good at the end as at the beginning of any event making around 1,100 or more horsepower all the time.
I have a customer with a drag boat doing exactly that and we refresh it every other year whether it needs it or not.

windsor wrote:Unported P51s made 920 hp:  https://www.429-460.com/t7463-572-cid-stock-kaase-p51-heads

(I think you're better off starting with A460s, but you already have the P51s)

That is some good food for thought!

There are a lot of ways to skin a cat.

With the tone of your post and I could be wrong, I would build a 598 A headed motor with nitrous. I'd run it on gas with a decent cooling system. Won't be much maintenance at all and will make enough power you won't have to spray it hard. Of course, what I think is spraying it easy is different than some of the phone calls I've received from guys on here. LOL

whatbumper wrote:There are a lot of ways to skin a cat.  

With the tone of your post and I could be wrong, I would build a 598 A headed motor with nitrous.  I'd run it on gas with a decent cooling system.  Won't be much maintenance at all and will make enough power you won't have to spray it hard.  Of course, what I think is spraying it easy is different than some of the phone calls I've received from guys on here. LOL

I like a bigger engine that doesn't have to work hard to make the power. Rpm's will be less, and I already have a NX Gemini twin pro power kit. Nitrous din't work all that well here in AK without the bottle heater going non-stop. My initial thoughts were that the P-51's would run out of steam but I am completely wrong on that one. An A headed deal would have more "room" for the future if it needs to go there. The only methanol experience I have was in a 410 sprint that I used to race a long time ago. That was not maintenance free by any means. You guys have any bore/stroke preferences to a given combination?

I'd build nothing bigger than a 4.300" stroke and would run a Morel .903" hyd roller lifter. Something about getting beat by a squishy cam really makes people mad.

Short stroke, big bore, hyd. roller cam. What would the cam profile look like Chris? Very curious

rollercam1 wrote:Short stroke, big bore, hyd. roller cam. What would the cam profile look like  Chris? Very curious

All other stuff would have to be determined then the cam could be nailed down. I have 3 drag week guys running hyd roller. The Morel .903" can take 280# seat pressure and 750# open load. 16 shock absorbers riding on those lobes going down the road helps out.

I had not even considered a hyd. roller. Would make things easy. When I get the budget finalized for this build I will give you a call if that is alright?

rollercam1 wrote:I had not even considered a hyd. roller. Would make things easy. When I get the budget finalized for this build I will give you a call if that is alright?

Thats fine.

18 bolt TFS A460 heads are the best bang for the buck.