school me on a 451 stroker

[trc54]

I've decided that a 451 stroker will be the best for what I want to do.
I've got a 400 BB from a 73 se charger. Is this sold as a kit? Also what is there to know about it and what did your build cost you?

 

[RustyRatRod]

This is called the 451 Manifesto. Pretty much sums it all up.

http://arengineering.com/tech/451-manifesto/

 

[super-bee_ski]

Thanks for that POST RustyRatRod.
Gee, this 451 COMBO flew under my RADAR.

 

[68 Sport Satellite]

This is called the 451 Manifesto. Pretty much sums it all up.

http://arengineering.com/tech/451-manifesto/

+1

I'm doing a 451 build right now and I researched this a lot before deciding on this build. It just got back from machining and balancing. I hope to get into the rest of the build in the next month or so. It should be a very robust engine with lots of torque. Have your 400 block cleaned and mag'd for cracks and sonic check the cylinder wall thicknesses.

Try to get a forged 440 crank if you can. You can save some money and use stock 440 rods with ARP bolts or go all out and get H-beams.

My goal is to run on California pump gas and be a street driver with once or twice a year trips to the track. I hope to get in the mid to high 12 second range for the 1/4.

There are a couple of other guys on here that have already built 451's and installed them in their cars. One forum member has done 3 of them I believe.

 

[demonram]

I built one for my 72 Satty. I used the 440 source kit. I've read about the bad mouthing on here, but I've got to say I am trully pleased with it. The shop that did the machine work was also. I had the block decked and deburred it's bored 40 over. I only went with a 484 hyd. cam and used their heads. It's got an eddy rpm and 750. The only thing I would do different, I WOULD NOT BUY HOOKER HEADERS AGAIN. It is great on the street, I've put about 4000 miles on it and have had zero problems. I put it on a chassis dyno just to see what it was. Horsepower is 370 torque is 460 at the wheels of course. I'm sure I could tweak and mess with it and get the horses up, but I am happy with the results so far. TAKE CARE and GOOD LUCK WITH YOUR BUILD!! HOWARD

 

[snakeoil24]

The 451 square bore stroke is the most ferocious wedge motor you can build.

 

[Wookie316]

Initially this was what I was going to build. But since the cost of a bigger one is practically the same, I went right out to 512 with my 400. No regrets going bigger. But a 451 would be a great build. Good luck with the project.

 

[RustyRatRod]

The 451 square bore stroke is the most ferocious wedge motor you can build.

I don't understand your statement. A square motor is having the same bore and stroke. Under square is more stroke than bore. Over square more bore than stroke (most modern engines). Since the 451 is made off the 4.342" 400 block and the 3.750" 440 crank it is very over square. I'll certainly not argue your ferocious opinion. I'm 100% in agreement there. Although there are some who think the 470 is about the best......I ain't among them. lol Not everybody can afford a 700 buck crankshaft, and the 451 can be slung together with box stock parts.

 

[snakeoil24]

I stand corrected you are correct.

 

[RustyRatRod]

I stand corrected you are correct.

It wasn't about bein right.....I just wanted to make SURE you weren't talkin about sumffin I didn't know about. Not everybody uses the same terms for everything. It's all good dude.

 

[68 Sport Satellite]

Initially this was what I was going to build. But since the cost of a bigger one is practically the same, I went right out to 512 with my 400. No regrets going bigger. But a 451 would be a great build. Good luck with the project.

I had read that going to a 470 or 512 ci motor would run a lot hotter than the 451 and that the 451 should have more long term reliability. How many miles on your 512 so far?

 

[Wookie316]

I guess i need to clarify. I have a 512 in the car, but have yet to do any street testing. The dyno numbers are great and it runs awesome. Maybe I will run into heat issues, but time will tell. If that is the case perhaps I will be wishing I went with a 451 instead. Hope all works out and I don't have any regrets though.
Is there a reason or theory why bigger strokers seem to run warmer?

 

[68 Sport Satellite]

I guess i need to clarify. I have a 512 in the car, but have yet to do any street testing. The dyno numbers are great and it runs awesome. Maybe I will run into heat issues, but time will tell. If that is the case perhaps I will be wishing I went with a 451 instead. Hope all works out and I don't have any regrets though.
Is there a reason or theory why bigger strokers seem to run warmer?

I'm not quite sure, but I've read that in more than one place. I guess it depends on your overall setup and your intended use for the car. I wanted mine to be a frequent driver for the street with minimal track time. I'll bet that with a proper cooling system and timing/tuning you can get it to run cool and nice. This is my first engine build ever, so maybe some others will chime in.

 

[demonram]

One of the reasons I went with 451 was I didn't want to worry about gas. I'm right at 10.5 compression. After researching the combos out there I didn't want to go over that. I know I could have thicker head gaskets or done other things to back it down but again I feel I made the right choice. I put in an aluminum 2 row(1") radiator and a 20" clutch fan and shroud from an 85 chrysler and I've only seen 200 on 95 - 100 degree days. We've had plenty of those this summer. I actually get better mpg than with the mostly stock 400 that had 78,000 miles on it. Of course when I jump on it that's a different story. I've got to say it still gives me a chill when I jump on it at 15-20 and it goes sideways. I also had the tranny done to handle it and I've got a 3.55 with BFG 275/60s backin it all up.

 

[vanrj1]

I guess i need to clarify. I have a 512 in the car, but have yet to do any street testing. The dyno numbers are great and it runs awesome. Maybe I will run into heat issues, but time will tell. If that is the case perhaps I will be wishing I went with a 451 instead. Hope all works out and I don't have any regrets though.
Is there a reason or theory why bigger strokers seem to run warmer?

I read when building my 422 stroker (340 block) that when thinning the cylinder walls and longer stroke on the stroker engines creates more heat. I went .060 over on my 340 block which most would say is maxed out and it ran 191° on the street with flex fan in the summer so I was happy. I think it boils down (no pun intended) to the cooling system you have. JMO

I am going to keep this 451 build for my next project, seems like a nice street motor and fun track a few times a year,

 

[terzmo]

built a 451 around 2500...installed in 70 charger...ran 12.40's consistent...nice motor

 

[68 Sport Satellite]

One of the reasons I went with 451 was I didn't want to worry about gas. I'm right at 10.5 compression. After researching the combos out there I didn't want to go over that. I know I could have thicker head gaskets or done other things to back it down but again I feel I made the right choice. I put in an aluminum 2 row(1") radiator and a 20" clutch fan and shroud from an 85 chrysler and I've only seen 200 on 95 - 100 degree days. We've had plenty of those this summer. I actually get better mpg than with the mostly stock 400 that had 78,000 miles on it. Of course when I jump on it that's a different story. I've got to say it still gives me a chill when I jump on it at 15-20 and it goes sideways. I also had the tranny done to handle it and I've got a 3.55 with BFG 275/60s backin it all up.

NICE!! What car is this in? I'm also running 3.55 suregrip and 275/60/15's in the rear with a 3 speed auto. My requirement also is to run on 91 octane pump gas.

Who did your tranny and what was done to beef it up? What stall and size converter and are you happy with it? I was thinking about ordering a 727 trans from Cope Racing Transmissions and getting something around 2200 - 2400 stall. I'm not sure on the converter size.

Can you provide any ordering details on the radiator you're using?

Have you taken it to the track at all and run the 1/4?

 

[RustyRatRod]

Is there a reason or theory why bigger strokers seem to run warmer?

Yeah. People cheap out on cooling systems. A 512 cube motor needs a very serious (expensive) cooling system. People get it all done and then think a 200 buck radiator will get the job done. Wrong answer.

 

[Wookie316]

Running twin electric fans and an Aluminum rad in mine. It is a 3 core. I know I may need to jump to a 4 core though. When I originally purchased the rad my build wasn't as big as it turned ou to be.

 

[SureGrip]

I was planning on doing a 496, but this thread makes a good argument.