I have a 460 with a 71 block (429?), 73 heads, and 76 intake manifold. I was wondering if anybody would know the horsepower on this motor. And if i have a good setup.

 

The D1 (1971 erra) block is a 460 most likely. Wasn't 70 the last of the 429's? The D3 heads are not to bad, and can support 600 HP if done right. You have not told us anything about the engine, is it fresh, bored, what cam, pistons, all stock...or has it all been updated with newer performance pats? Headers, carb........tell us all you can and after that a guess can be manufactured. Saying "A good set up" can mean different things to each of us. My idea of a good setup would be a block that is remanufactured to ensure all is straight and true, .030" over bored with a set of inexpensive flat tops, the D3 heads have the ex side worked over to the best of your ability, and you have a nice little hydraulic cam and a set of roller rockers on screwed in studs. You have matching springs for the cams, and made sure everything was assembled with care. Tell us some more :]

 

The motor was just rebuilt and bored .30 over and moly rings. It has domed pistons and an rv cam. It has an edelbrock 750 cfm carb on it. I have a set of schoenfeld tractor pull headers with 2 1/8 inch primaries and a 4 inch collector. It probably has only 1500 miles on it since the rebuild. A very trusted engine builder built this motor for me and has over 50 years experience building motors. I was lucky enough to be the last person he ever built an engine for.

 

OK, give me the 0.050" cam specs, duration, lift, lobe sep

What compression ratio?

Are the D3 heads ported on the ex side? If so do you feel they are ported professionally or a basic do-it-yourself touch of and blend? Stock valves or did you change to a cj intake valve?

Single plane intake, or a dual plane like a stealth, or a factory iron?

Those headers, are they going into 2" ex and mufflers, or into a free flow mufllers and 3" pipes?


I know you think Im busting your chops here, but there are so many variables, I need more details. I dispise the term "RV" cam, whats that mean.......its a 224 duration, .510" lift on a 112 lobe sep? RV cam tells me you have a cam just over stock that maximizes cylinder pressure for low RPM TQ, it pulls great down low and falls on its face at about 4,500 RPM's.....Toss me the cam specs and I'll do my best guess at what you have.

And a question for you, why the dome pistons? Domes are not the best choice if you had an option to plane down the heads.

The flame front can travel faster with a flat top, the dome forces the flame to travel over a hill ond down the other side, and you have a much better chance of having a flame out situation in a cylinder with a dome. Just my opinion.....I do know if your limited on options, and your trying to make power on a budget, domes can squeeze you into a higher HP/Cmpression bracket with minimal cost, such as buying new DOVE/PI/SCJ heads or doing a slightly odd angle mill of the head and intake surface of the head. I have seem SCJ heads angle cut from 0.000" to 0.110" for a 57cc chamber. Thats getting the squeeze on!

Last question, what is your expected operating range in RPM's? Is this a truck engine for trailer towing, a weekend racer truck that will be seeing some 6000 rpm runs past the rice rockets? I've run a couple "RV" type cams and found them to be very limiting in the upper mid range RPM's....like they sign off at about 4,500 or 5,000 at the best.

 

Compression I believe is 9.5 to 1. No porting or polishing on the 73 heads heads. I will have an Edelbrock performer rpm intake with the edelbrock 750. Headers are tractor pull headers...they come right out of the hood with no mufflers. I think i am going to ditch the rv cam and go with a comp 268 magnum cam with matching valve train. Will this be too much cam? With this setup what will i be looking at for horses then. I am putting this motor in my 1970 Highboy with 4" skyjacker lift and 38.5" boggers. It will be used strictly as a mud racer in the msmra circuit. It will regularly see 6000 rmp. I am just curious to see what my stock 460 motor has with the rv cam(.224 dur and .510 lift) cast iron 4bbl intake, 750 cfm edelbrock, 2 1/8 headers(straight). Domed 9.5 to 1 pistons and Stock rods.

 

I would guess with that combo you should be in a 350 hp area. With the heads worked on the ex side and a bit more cam you could easily see 425-450. For the RPM's your looking for a set of ARP studs and roller rockers with push rod guides would be a great idea. I have thrown/bent/mangled a pushrod at 5500 on stock heads on the street. I would say your HP peak will be at about 5K RPM and the torque should peak around 3200 with that RV cam. If you look up the specs on the Comp 268 grind I'll tell you what I think it will look like.