Build me a 800hp NA 512 b block using pump gas

[Crutchybilt_Per]

Fullbore71, you sound like you have the same problem my father had when I built his engine. There are so many more choices out there then say 10 years ago. The rpm heads def can make the power. There is some work involved with that though. We have them on my fathers 499 and he made 789@6600 on 93 octane. I have not worked with the Trick Flows yet. They look good out of the box for sure. The victor heads are a better head for sure then the rpm's. If E-85 is scarce where you are at then just build a true pump gas engine. At that point be honest with yourself as to what your goals are. What ET you need to be at and what its duties will truly be. The problem with what you are doing is that everyone has an opinion on how you should build an engine. Not all are bad or wrong per say. For example I am building a 446 with Pro comp heads to go deep in the 9's in a 3000lb duster. I am only doing that because I was told it can not be done. So ok, as an engine builder I will prove them wrong. Also with a flat tappet cam just for spite lol. That engine will make about 760hp or so. To put that into perspective, it does not matter how you get there, if its in your budget and you are happy with it then rock on. To make the power you want to make, you will need good air flow and a cam that compliments your top half. But then your job is not done. Driveline and chassis plays a huge part in your equation. I guess what I am trying to say here is for what you are doing, you could almost pick a head by throwing a dart at a wall. What ever it hits you can make work. Just some will take more work than others. What parts and pieces do you already own? If you can tell us that then you might be able to get a better response on what direction you should try and go in.

Sorry for the long wind, but I hope it brings a little perspective and not confusion. If you would prefer, you could always call me, I would love to help and get some of your questions answered.

757-813-6600

Don

 

[Fullbore71]

Fullbore71, you sound like you have the same problem my father had when I built his engine. There are so many more choices out there then say 10 years ago. The rpm heads def can make the power. There is some work involved with that though. We have them on my fathers 499 and he made 789@6600 on 93 octane. I have not worked with the Trick Flows yet. They look good out of the box for sure. The victor heads are a better head for sure then the rpm's. If E-85 is scarce where you are at then just build a true pump gas engine. At that point be honest with yourself as to what your goals are. What ET you need to be at and what its duties will truly be. The problem with what you are doing is that everyone has an opinion on how you should build an engine. Not all are bad or wrong per say. For example I am building a 446 with Pro comp heads to go deep in the 9's in a 3000lb duster. I am only doing that because I was told it can not be done. So ok, as an engine builder I will prove them wrong. Also with a flat tappet cam just for spite lol. That engine will make about 760hp or so. To put that into perspective, it does not matter how you get there, if its in your budget and you are happy with it then rock on. To make the power you want to make, you will need good air flow and a cam that compliments your top half. But then your job is not done. Driveline and chassis plays a huge part in your equation. I guess what I am trying to say here is for what you are doing, you could almost pick a head by throwing a dart at a wall. What ever it hits you can make work. Just some will take more work than others. What parts and pieces do you already own? If you can tell us that then you might be able to get a better response on what direction you should try and go in.

Sorry for the long wind, but I hope it brings a little perspective and not confusion. If you would prefer, you could always call me, I would love to help and get some of your questions answered.

757-813-6600

Don

First off welcome Crutchybilt and thank you for the response. You are totally correct in every way here. Yes there are so many choices to accomplish this I hope. I've seen 770hp-778hp-780hp but no 800hp out of a stock 400 b block. My main goal is about like yours with your 446 engine. It's a personal goal to build a 800hp b-block using a stock block and put this car 9 flat in the quarter. Just something I want to do. After that it will be detuned and street driven and no I don't care about street manners in anyway. Basically like a drag week engine. By street driven it would probably see maybe 300 miles a year. IF THAT. I haven't any desire to constantly be running at the track after I prove to myself this can be done. I started by thinking of going Edelbrock MW Victors and a full port job but have been told they are a lot of trouble. This I can neither confirm or deny. The car's weight has not been verified as of yet but it's backhalfed and continuously being lightened with fiberglass body panels etc.etc. and 1 seat. I totally agree that the chassis plays a major part in this equation. My chassis guy set this car up for SG. He's knows his stuff and will be there to help get the chassis dialed in. I have a friend on the west coast that runs a basic 600hp small block that runs consistent 10.0's only because he doesn't want to go full cage. As far as what I have I already own? 4 400 blocks and a cap and girdle setup from BRC. That's it!!! Everything else will be bought. This idea came about about a month ago out of the blue so I haven't bought anything else yet until I could get some info on what other people thought about this. It will be done somehow someway. I have never built a big block Mopar before so was hoping to gain some advice from the experts. BTW I have built dozens of Ford's, Chevy's and SB Mopars so this isn't my first build. I hope this clears things up a little and thanks again for your time and input on this.

 

[Fullbore71]

BTW...I came up with the 512 but I am also open to options there too. I figured bigger is better. Right??

 

[mguner]

A friend of mine with a machine shop says that once you get around 700HP the main caps like to walk around and that billet caps, studs and a girdle should be considered mandatory for any kind of life span. What say those of you with one of these beasts?

 

[Crutchybilt_Per]

Fullbore71, Well what you seem to be thinking is not to far off. As far as bigger is always better, well that depends on the heads you will run. Remember it is an air pump and you have to be able to feed it. Im not apposed to bigger by any means what so ever. Tom Molnar at Molnar Technologies has really nice cranks and rods. All he builds and I can tell you his stuff is top shelf at a little more than eagle money really. I can see a 512 being built. I agree with the girdle part. Also do not shy away from at least a half fill in the block. Do you have the aluminum or billet main caps? Not a fan of the aluminum caps. Many say they act as a spring and soak up the load in the bottom end. But if your balance job is right then you should not have any vibrations. On top of that the bottom needs to be as tough as possible. Depending on how you build this animal, 800 is possible. Wont be easy to get it out of that but it is possible. I am assuming you will be 4.250 by 4.380. Thats not a bad bore stroke combo. Another thing to pay attention to is in the block, take the time with a burr bit and go after all the casting flash you can get to. In the valley, the cam tunnel, the block skirts all of it. This can help relieve stress risers as well as get rid of anything that can come loose over the course of the engines life. If you fill the block leave the cam bearings in it and a cam shaft. It is not un common to have cam fitment issues with the older blocks. Even more so after they have had a core shift. Most certianly go with a swinging pick up. If you end up oiling like a chevy for the top end make sure you bush the lifter bores for good oil control. That also keeps more in the bottom where you want it. Go with a chevy 2.200 rod journal. That makes your rod bearings cheaper and slows the bearing speed down. Get huge and heavy push rods. Smith brothers are wonderful. Do not worry about weight there. Going light there does no good. Look at todays Pro Stock cars, their push rods are huge by large so they dont deflect through out the power band. You can actually lose lift with a whimpy .080 wall push rod. If you can get it to the point, try to put the piston about .018 in the hole. That will be predicated on your accurate deck height from the machine shop, then rod and crank length. Do the math and get your Compression distance. Have it in the hole so you can run a .027 cometic and get rid of some dead zone as well as promote a better flame front. You will be in a solid roller. So a good stick from comp or whom ever, good lifters and stout springs. Ti retainers and try to set up for lash caps. You dont need ti valves, but a good Ferrea or Manley sever Duty for example. I am obviously rambling at this point so I should stop. But I can tell you it can be done. I have one 498 out of this shop with Victor heads, and is fuel injected making 812 at 7800. But it is a lot of work and a lot of attention to detail. Want to make the power really easy then get your hands on a B! PSO head lol or the predators, but be prepared to open your wallet very wide.

 

[IQ52]

Thank you again IQ52. Now...to sound really stupid here. The first article you sent showed a 451 with ported RPM heads (349@800) making 770hp on pump gas. You said the Victor heads were troublesome. Here's a thought that might seem stupid but I have to ask. I keep seeing you guys talking about the Trick Flow heads and how well they flow OOTB compared to RPM's. If they flow 332 @ 700 with out porting I'm thinking they should possibly be able to be ported enough to surpass the 349 flow it took to reach 770hp from your combination. Any thought on this?? E-85 around here is scarce. It would be easier to run to the track and just get race gas.

TrickFlow heads come fully CNC ported right out of the box. I haven't had the time to do any more work with the TrickFlow heads to see if more improvements can be made to them. Looking at them I believe there is more potential. The TrickFlow 240CNC heads were not designed to be a race head but rather a better option than the typical standard port location of the Edelbrock, Stealth or Sidewinder type head. There have been other heads previously mentioned that would be a better start for a race head.