Thoughts on dirt track motor for drag racing?

[splitdecision71]

So I just bought a 421 short block that was built for dirt track racing. I bought at what I thought was a reasonable deal. Did I screw up? It had Brodix 11x super spec heads but I sold them and Im using my own brodix heads. Going in a 1964 Chevy two that weighs around 2700lbs. Powerglide with 5k stall converter, 4.56 gears.

engine build sheet:
SBC -421
Lightweight Eagle Crank 3.875 stroke
6” Lightweight Eagle H Beam Rods
Diamond Pop Up Pistons 8cc dome 4.155
Molly Rings
All bearings are King HP “blacks”
“ All parts are balanced “

Herbert Camshaft CR-285 4x7 swap firing order
adv. dur. 320 int - 330 exh
@ 050 285 int - 295 exh
valve lift .684 - .657
110 lobe center
centerline 106
@ 050 int open 35 close 69
exh open 78 close 36

Herbert Roller lifters
Double roller timing chain

Brodix 11x 2.100/1.625 valves 64 cc Max ported for fel pro 1209 gaskets
Jesel shaft rocker arms 1.65 intake and 1.60 exhaust

Super Victor Jr. intake
Champ oil pan
2 pc timing chain cover

[CamKing]

That's no circle track cam.

That'll work from 5,000-8,000rpm for drag racing.

[splitdecision71]

That's no circle track cam.

That'll work from 5,000-8,000rpm for drag racing.

Thank you for your input sir.

[MadBill]

You didn't say, but that sounds like a drag race car, in which case the cam isn't necessarily wrong.

[cgarb]

Doesn't seem too hateful of a combo. The cam may be a little large in the duration numbers for a 2700lbs car. Is it a large tire car...32 or taller slicks? How hard to you want to turn it? Going to need to crank that one up some. Only problem I see with that is the eagle lightweight H beam rods. I think they have a reduced HP rating on them. Good starting point anyway if you got a decent deal on it.

[midnightbluS10]

I'd go for it. There was a rumor around my track for a long time that the Harvey's(Sam & Justin Harvey of No Prep fame) with their $90k engine got slaughtered by some guy with an old dirt track motor that drove to and from the track in his 93 5.0. They had a Blue Chevy II at the time, which is what they're driving in the 2nd link below

https://youtu.be/KZZXX79xsqU


https://youtu.be/2CREjYvTvTc




What kind of engine block? Stock? Little M?

[splitdecision71]

You didn't say, but that sounds like a drag race car, in which case the cam isn't necessarily wrong.

Yes sir, kinda what I was thinking. I'm probably going to have to twist it pretty high wouldn't you say?

[splitdecision71]

Doesn't seem too hateful of a combo. The cam may be a little large in the duration numbers for a 2700lbs car. Is it a large tire car...32 or taller slicks? How hard to you want to turn it? Going to need to crank that one up some. Only problem I see with that is the eagle lightweight H beam rods. I think they have a reduced HP rating on them. Good starting point anyway if you got a decent deal on it.

Car has 31x13x15 slicks.
I gave $4000 for the motor assembled with arp bolts, intake, brodix 11x superspec heads, cam, lifters,timing chain, oil pan, water pump, and schonfield headers. I sold the heads intake and headers already. So I'm in it less than $3000 and kept short block assembly and all other parts.

[splitdecision71]

I'd go for it. There was a rumor around my track for a long time that the Harvey's(Sam & Justin Harvey of No Prep fame) with their $90k engine got slaughtered by some guy with an old dirt track motor that drove to and from the track in his 93 5.0. They had a Blue Chevy II at the time, which is what they're driving in the 2nd link below

https://youtu.be/KZZXX79xsqU


https://youtu.be/2CREjYvTvTc




What kind of engine block? Stock? Little M?

I know where this is fixing to go now. It's a 509 casting 400 block. I know there is going to be lots of comments about that. The whole deal probably went south now because of that. All I can say is the guy spent all his money on prepping block and not me. I know it would have been a waste to prep a stock block when you can buy an shp for less. To be honest I'm not sure what kind of power I'm going to be making anyways. If this combo gets me where I want to be then I will start looking at getting another block to put these parts in. That being said I may not have gotten a good deal in the long run. Guess time will tell.

[racear2865]

Sometime you get lucky for a weekend but it may only be a weekend. I was lucky one week end way back when but then her husband came and got her.
reed

[splitdecision71]

Sometime you get lucky for a weekend but it may only be a weekend. I was lucky one week end way back when but then her husband came and got her.
reed

Like I said, not sure what the combo is going to make for power. Up to 600, Im probably ok. More than that it will be a matter of time.

[user-17438]

Sometime you get lucky for a weekend but it may only be a weekend. I was lucky one week end way back when but then her husband came and got her.
reed

Like I said, not sure what the combo is going to make for power. Up to 600, Im probably ok. More than that it will be a matter of time.

if the heads are prepped well, north of 700 is doable with the cam you have.

[splitdecision71]

Sometime you get lucky for a weekend but it may only be a weekend. I was lucky one week end way back when but then her husband came and got her.
reed

Like I said, not sure what the combo is going to make for power. Up to 600, Im probably ok. More than that it will be a matter of time.

if the heads are prepped well, north of 700 is doable with the cam you have.

Im not a professional but they look very nice to me. If in fact it makes north of 700hp I will be very impressed. I will definitely start looking for a block!

[cgarb]

If you look up some of my posts on my 421 build I made 651 dyno HP on a 509 block that is filled and had splayed caps put on. Its lived a happy life so far this season, but I have not ran it a whole lot due to weather and driving another car at times. Its 50/50 on stock 400 blocks...like you said, its already paid for so run it till you have an issue and hope it isn't too bad. This is my last attempt with a stock block because I am out of them at the moment, and I want more power. My machinist and dyno guy told me he wouldn't be afraid of my engine in a drag car, he said if it were going in a dirt late model...it don't have a chance. If I was in your shoes, I would run what you have, shift it at least 7200...maybe 7500 if it likes it and try to have the converter loosened up to around 5500 rpm.

[splitdecision71]

If you look up some of my posts on my 421 build I made 651 dyno HP on a 509 block that is filled and had splayed caps put on. Its lived a happy life so far this season, but I have not ran it a whole lot due to weather and driving another car at times. Its 50/50 on stock 400 blocks...like you said, its already paid for so run it till you have an issue and hope it isn't too bad. This is my last attempt with a stock block because I am out of them at the moment, and I want more power. My machinist and dyno guy told me he wouldn't be afraid of my engine in a drag car, he said if it were going in a dirt late model...it don't have a chance. If I was in your shoes, I would run what you have, shift it at least 7200...maybe 7500 if it likes it and try to have the converter loosened up to around 5500 rpm.

Thanks for the encouragement! LOL. Whats your set up on the 421? Id like to know if you dont mind. I suspect being the light weight assembly on the set up I have is going to help it live, or at least Im hoping so. NEVERMIND!!! I see you told me to look up your build. I will do so and THANK YOU!