Thread: sbc 400 Help

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Hello this is a great site and I,ve allready learned so much but I,m going to have to ask for some help and opinions. Basicly what I'm building is cj5 jeep frame which will be streched about 2 1/2 feet and have a roll cage built onto it. I know thats a little differant than what most of you guys do but I'm hoping you can still help me. I want to use a small block chevy either a 350 or a 400 but I'm not sure which will work better. I would like to have about 650 -700 horse if thats not too unreasunable. I've rebuilt engines before but have never built a high horsepower engine its not going to be a drag racer more of a play in the mud and in the sand dunes but I'll probly end up dragin their anyway so I would like it to be able to handle NOS too. What I'm looking for is a engine that can do a lot of running and last some time before it has to be rebuilt and not just the 15 seconds down a sandy strip before being turned off. If anyone could give me some ideas on which engine to start with and how you would build it would be appreciated. Money is not an option only the years it take to earn it and I've got a lot of years I'd rather do it right than to do it quick and cheap.

Thanks alot

Trenton

if you have to use a small block chev use the 400 block,350 crankshaft because it has counter weights and is stronger . dont use the 400 heads as the bowtie heads are shit, use 350 double hump fuelie heads or a set of performance heads from an aftermarket manufacturer/supplier, there are pleanty availiable in the states then just work your way along from there. or buy a book on hotting up sbc's.

I am not one to talk directly about off-road mods, but I did run into someone who had a Jeep wagon tricked out and professionally raced( and won) with a sb400 in it. he switched cranks with a 327 for more low-end power, which you will need for serious rock crawling. not sure how much hp he had, but the reduced compression would probably accomodate for the NOS. But I am not sure why you would need so much hp and NOS for an off-road vehicle. But, to each his own.

You don't need mega horsepower for a Jeep to be competitive unless your on a paved dragstrip. My friend Burt bought his wife a CJ5 with the AMC 6 cyl. engine I think it was a 232. She got interested in pulling competition and did very well beating out a lot of sbc conversions. She wasn't satisfied so he built her a 400 Chevy engine. He had his own engine rebuilding bussiness. The 400 would spin the tires when the six would just dig in and pull. You can't win if you break traction and the 400 did just that. She gave up pulling and rock climbing and tried sand drags. By this time they had replaced the body with a complete fiberglass body and added a blower. On her third run she lost it and totalled the Jeep. She only recieved minor injuries thanks to the roll cage but there was nothing left that was useable on the Jeep except for two tires. I have a 4 cylinder cj3a that was better at pulling and rock climbing than the monster machine they built. I never entered it in the sand drags because I couldn't compete there but I only have $1200 in my Jeep and still enjoy it.

Maybe I am just an old grumpy person, but I hate it when I hear NOS. Guys, if you can't learn to make horsepower without a bottle, maybe you need to be weaned from the darn bottle. Anyone who is knowledgeable can get more than enough h.p. with old fashioned engine mods.

I see what your talking about that others don't.
A jeep in the sand is a HP robber. I know been there done that.
You Must have been thinking of new Axles cause you know they will say, C-ya with 350hp in the sand. well Mine did.. I do turbo V8's now and one in a jeep would be very cool. I can send you a list of parts you would need for a Turbo SBC V8. You are thinking how are you going to feed it.. Blow through 600 cfm EDE #1405 works fine with the Air gap 1500-6500 man, two T-3's are Easy to get and I have a dyno sheet with the 383 twin T-3's 491lbs torqu@2000RPM and max's to 746lbs@4500 and the power 337hp@3000rpm's and max is 708@5500rpms it is a hand full in the rain. but for the street going to the store my wife can drive it.
very smooth. here is your list of parts for it. Low Performance/Ported, Large Valves 202's, SRP Pistons 10.3 to 1 or less.40 or 50% Intercooler- I know it helped bigtime and water Inj, Performer cam/hyd. Air gap rpm a must have.
6deg Timing Adv. very low but it works cause there is so much torque $39ea, kit to boost in dash each. to 13lbs Boost.. My Turbo guy that rebuilds them got me these and yes you can run it down to 5 or 6 psi if you want for in town/hwy. 92oct. w/3" flow master’s And I build my own headers for my motors there easier than you think. Jegs.com has most of my parts that I buy and they have headman builders kits. The stock HEI works fine w/ a 48.000volt HEI coil, by MSD #121-8226..$38.99 for it. Because you are not revving up to 10 grand and the motor falls off it's face really fast after 6 grand...more like a rock off a cliff. I have done a sbc 400 with a roller cam .510 lift int, ex, w/ roller head rockers and every thing the same and it only gained Max 780@6000rpm and 866T@4500rpms and the 383 is in my 1987 El Camino with a Z28 front end and wheels ET DOT slicks in the rear. runs very well still and the only hard part that I have noticed it the jetting needs the next size up metering rods. Or more at times in Oregon., But It was Okay in Boise ID with stock, But I only get 12 mpg on the Hwy@65mph @2100rpm @ 6psi of boost. Don't ask me in town cause the little Fast and the want-to-be- Honda’s I like to eat up. I got it at 13psi all the time. More like 4 or 6mpg the way I drive. If you want to spend $1800 more you can get two RayJay 300F Turbo’s and look out. The 300F by RayJay is the KING of SBC- (Cause they Keep Reving to the Moon) World but the motors don't last as long But for drag only. We did a 454 with Dart heads w/345cc runners 2.30/1.88 vales .600 + roller cam. 950cfm new holly carb. #510-0-80577,Victor Man, " And you Know"…300F’s The Dyno only went to 1000hp and 1000Torque and was doing that @4000rpm. Ok $ my 383sbc with the Two Rebuild T-3s and in dash boost kit and welding my own headers up and all my parts and driving down the road is $4.863 for 700hp is not bad. But blowing 2 Turbo-350s Trans now is getting old but the 3rd, one in car now is a TCI's T-400 w/ tci's Brake-a-way anit-ballooning plate. Jags part #890-240901 $280 Now I really feel it and still going strong. Yes there is a 9” in the rear. Done broke every thing once or more but sure is fun doing it. My next truck is going to be a Jeep Grand-Ch, Mod frame and cut down 1 ton Axles and I am starting this on Jan/3rd/2004 w/ 360mopar motor Big valves 2.08 int heads and 4 T-3's..Yes "four"... Like I said there cheep but man do they work. But the rev-limiter will be set @ 4500rpms... It won't need any more. PS, If you go turbo and want more power. You can't run the Ede,1405 600cfm carb, More open heads like the Dart pro 1's and then we tryed the Holly 1000cfm MPI commander that works very well and it's Universal with any SBC SBF Mopar Ect, Part # 510-534-183 (and they make a 2000cfm too.) On a 5.0L 302 motor the is still good looking 1991 Mustang and it's HP Dyno is with 2 T-3's 973HP@7500rpm But now you are talking 3 times more $ than I We have in the El Camino. So your 700hp motor for your jeep is for real. Emails are ok to rossmanracing@hotmail.com

Oh here is a Dyno 2000 for the 5.0L 302 motor Photo if you thought I was Out there!! : ) Emails to rossmanracing@hotmail.com

No offence BigBird but computer generated HP/Torque numbers mean no more to me than other claims made by people who don't have REAL dyno sheet.

Building a SBC to make those HP numbers is possible, making it live past one dyno run is expensive. First you need to decide what size engine you want to build. Check some of the previous posts and you'll see a several discussions on the heating issues associated with the 400 SBC and the reasons. If you choose to build a 400 cooling will likely be an issue especially in the enviornment it's going to be living in. Although you would give up CIs a 350 or a 383 stroker may be the way to go.

Block: Either go with a new block or one than can be cleaned up with a minimal overbore (.020 for a 400, .030 for a 350).

You'll need 4 bolt mains and although you could start with a 4BM block, I think I would go with aftermarket splayed 4 Bolt main caps.

Wether you go with a new or used block have it sonic checked, and all the work done by a competent machine shop.


Rotating assembly:

A steel crank will be a must and again I would go new (if your doing a 400 or 383, the factory did not make any steel cranks for the 400 so you'll have to go aftermarket). If you find a used crank discard it if it does not clean up at .010/.010.

Stay away from aluminum rods. Buy the best set of steel rods you can find. At a minimum you should have them magnifluxed, big ends checked (even if new), the rods shot peened and the beams polished.

Pistons should be forged. Even though the hypereutectic are stronger than cast and lighter than forged, they are more brittle and less able to handle the abuse of the HP you want to make.

Have everything balanced. A good starting point when choosing a shop is to ask them what tolerance they hold their balancing to. If they say anything more than plus/minus 1/2 gram find a new shop.

Use the best fasteners you can find, and use studs for the mains and heads.

Congratulations you have just built a VERY expensive shortblock. (to get an idea, pick up a PAW/Summit/Jegs catalog).

The top end of the engine; cam (I would definatly go a full roller set up), heads, induction, exhaust etc you'll need to define your paramaters a little better. Are you going normally asperated, supercharged,turboed,NOS? You really need to know the RPM range your really going to try to make the engine live in (generally with high HP numbers you want will only occure in a VERY limited RPM range). For that you need to define what your vehicle is going to do, weight, gear ratios etc.

Heelllooowww! I was talking about the guy with the Jeep that wanted 700hp Look ^Up^ and the is a good base to build HP Dyno 2000. It's only 19LBS of torque off--It says it has more than the real dyno in Eugene Oregon. We use it to find out where to start building one thing----HP! And we know it will be close ( But yes that is a good SBC that your talking about for a rebuild that is cheep.) WILL NOT WORK FOR TURBO SBC,The response was to the man asking if there was a way to make 700hp sbc, for his Jeep And I can Show you Jimmy’s Dyno sheet for the 5.0L and the numbers are the same on the HP side. 973hp And I build the motor and still we drive the car. In 2001 we started doing turbo V8's. And the T-3 By Air-research is the way to go without going to crazy on HP. The Twin turbo 454 we did for Pat was way more than you want for the road. This is a race shop. This is what we do. But for a Jeep in the sand with 4 paddle tires. It's the cheapest hp to build. If you want to find a T-3 turbo's they came out of the ford T-bird coupe and mustangs with 10 lbs of boost stock. WE DO BIG TURBO MOTORS ONLY PLEASE, No more Honda's, No 4 cyl, ect, Thanks. BigBird = rossmanracing@hotmail.com

If you don't think a twin turbo sbc, can't make 700hp. your dead wrong. Are grope fly all over the world Like Chuck Shertlift Indy and formula-1 motor specialist. This is where we get are info from. This we got started turbo building V8’s

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I'm not a big fan of spendy unnecessary engine mods, but I have been in a debate with sticking with my edelbrock performer rpm intake with a manual choke 650, or swapping it out with an aftermarket TPI. Any suggestions would be greatly appreciated