Thread: 4.3 v-6 buildup

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I know this thread is a little cold but to who ever is interested.
A 4-71 blower can be put on an early head 4.3L (pre-vortec) by using a 229 Chevy V6 blower manifold. I have a friend who has one on a Thames truck which puts out a good 500HP on a nitrited cast even fire crank 4.3L. He drives it everywhere was at the Yellowstone tour last year. So it can be done.

Originally Posted by keotie

Man, I like all the info Ive heard here!

Assuming a near stock rebuild (stock short block, mild after market cam, intake and say 600cfm carb., along with the vortec heads-------any ideas of possible torq. and H.P.?) Next Ill be asking if someone wants to come do it for me!!!!!!
Thanks again for the information guys,,,,,

You should be in around 225HP maybe 250HP which is comparable to a 283 4bbl Chevy. Actually if you keep the hood closed most will believe it is a 283. I picked up a dirt cheap 92 Astro van 2wd with the 200HP "W" engine (CPI inject was shot putting a carb on anyways) and 700R4 trans for my project. I can use the front calipers which are the same as the late 80's Camaro, steering column, hydroboost brakes and yes the front rotors 12" 5 on 5" bolt pattern, with a little machining the MII spindles will take an A3 outer bearing and an A13 inner bearing. By using a right hand axle on the left side I can narrow the 7.5 10 bolt to a usable width, all this on a budget. Sorry getting off course.

i like the idea of a 4.3 in a pinto. mated to a 5 speed manual or 4 spd auto, either way it says sleeper. of course, i also think a turbo tbird setup or a tbird super coupe v6 would be fun too. maybe im just wierd.

Originally Posted by dwaynerz

i like the idea of a 4.3 in a pinto. mated to a 5 speed manual or 4 spd auto, either way it says sleeper. of course, i also think a turbo tbird setup or a tbird super coupe v6 would be fun too. maybe im just wierd.

I have thought of building a GTP Supercharged 3.8L V6 with a 5 sp in a Track T.
dwaynerz its not weird, its cool.

I owned a Chevette that we swapped in a Bowtie common pin Brodix head 4.3.Ran 10.90's on the stop like clock work.All was a result of the comic book "Hot Rod"
article that stated Don Hardy had built one.Well they tried and decided it was too hard to mass produce.After I had thousands invested and called them for the headers I found that out.

These 4.3's follow the same formula.Ya want to build something different??.It's going to cost a lot more.............

If you want to do something simple with the 4.3's (not the reverse rotation ones),follow the marine builds for them and you can get some reasonable output.

BTW-I am having a hard time accepting the fact of a blown 4.3 putting out 500hp without it being very,very,close to not being street able.That is just a little short of 2hp per c.i.and on stock heads???.

Originally Posted by 1gary

BTW-I am having a hard time accepting the fact of a blown 4.3 putting out 500hp without it being very,very,close to not being street able.That is just a little short of 2hp per c.i.and on stock heads???.

Well believe it or not it is absolutely true. Canadians are like Aussies, they don't care what people tell them they can't do they just do it.

You don't need all the racing crap to build a decent 4.3L on the street. The problem is people seem to think that they have to have small block power to be credible. This is a load of bunk, just build them for the street and drive them, there is nothing wrong with a 200HP V6 of any brand. There are a lot of 4.3L v6's on the street in all types of street rods that people think are small blocks. I have seen a lot of them at different shows. They are finally becoming common place. I don't know what the problem is with 4.3 nay sayers their just a version of the small block.

Look I don't care about Roddin' politics. I just want to build rods and customs with what ever I feel I want and have to use. Isn't that how it all started, use what ever you have at hand and for the budget you have?

Originally Posted by Two8tyThree

Well believe it or not it is absolutely true. Blackie asked Russ to bring it to the Fresno show a couple of years ago. Russ drives it to different cruises.
You can find his Thames in that Blackies Fresno Custom Car show and at the Yellowstone cruise site if you want proof.

http://www.horton.on.ca/customer_cars/russ/russ1.htm

Canadians are like Aussies, they don't care what people tell them they can't do they just do it.

You don't need all the racing crap to build a decent 4.3L on the street. The problem is people seem to think that they have to have small block power to be credible. This is a load of bunk, just build them for the street and drive them, there is nothing wrong with a 200HP V6 of any brand. There are a lot of 4.3L v6's on the street in all types of street rods that people think are small blocks. I have seen a lot of them at different shows. They are finally becoming common place. I don't know what the problem is with 4.3 nay sayers their just a version of the small block.

Look I don't care about Roddin' politics. I just want to build rods and customs with what ever I feel I want and have to use. Isn't that how it all started, use what ever you have at hand and for the budget you have?

Dear Sir.I question the 500hp rating.Not the use of a 4.3 or the car,which btw is a very nice car,or him driving it to shows.I does get irritating to read everyone has 500 hp cars and knowing better.The split journal crankshaft I have good reason to doubt it would hold up under that kind of strain or would hold up for very long anyways.From what you are saying,his is holding up,so again 500hp....well I doubt it.I could understand you comments if I haven't gone down "that" road to build-up a Childress Bush grand national 4.3 that I bought at the Indy drag auction yrs ago and for good reasons spent the big money to get around the 4.3's design flaws.So I am setting here from a been there-done that backround and fully understanding the stock 4.3's.

Now is his engine a very stout 4.3??.Well I trust what you are saying and I would guess it is.You know full well what has been apart of hot rodding too is cars that are all show and no go,no show and all go,and any combination of the two.Here in Roch,NY-the Street Rodders club have members that readily admit they build a nice looking street cruiser.Nothing wrong with that at all.

I am stepping off topic with this comment.Damm I am sick of street cars making claims to hp.Who the hell cares??.Don't drive normally in whose higher RPM ranges anyways.We all have fallen in love with HP and we all know fully well in street cars,torque is king.It is more of the same romance that comic books like Hot Rod promote.

Originally Posted by 1gary

I am stepping off topic with this comment.Damm I am sick of street cars making claims to hp.Who the hell cares??

I don't care, but someone did care enough to compose a lengthy treatise refuting the claim.

Bob

Well Gary I really appreciate your comments but what you believe is up to you.
As for calling me a liar that's another matter. I think an apology is in order.
Anyways what is your problem? If you don't like the post don't read it and move on.

http://www.hotrod.com/techarticles/e...all/index.html
They used a Rotary Blower not even a 4-71 and it is possible with stock style heads!

This is the last I will comment on this particular subject.

Don't recall calling you anything of the sort.

Well, I kinda agree with you, 1Gary-----we all do put too much emphasis on HP. Since we all know the old saying "hp costs money, how fast do you want to go?" I think at my age and "needs" for my next build, Ill want something respectable b ut not a real ground pounder. I have been checking out the 4.3 marine engines-----change exhaust manifolds, add some "go fast" chrome and they just might be something to consider.
Originally I was looking at building up a 64-5 chevy II next, but now Im considering a 67 chevy shortbed instead. I think the duece would be lighter and have more "jump" from a 6 than the truck would---but with either, Im looking forward to the "wow" factor of opening the hood on the v6.

For those who are truly interested.

Campbell Automotive can build very nice Chev 4.3L V6's with nitrated cast cranks.

See post below.

http://www.youtube.com/watch?v=sZ4zWQR8qwE

www.campbellautomotive.com

www.campbellautomotive.com

I hope this abates some of the myths out there.

Originally Posted by pat mccarthy

yep there parts like you said 350 parts will work theres cams erson makes them .the marine hyd roller is a good cam for some build iron and came with a 4 barrel intake . there was i think bush class or some road race class that gm made alum blocks intakes .at one time a friend of mine had every part that gm made for them i did some but very mild builds.chevy power book shows some stuff in it

Pat the cam you are talking about is it the 225hp cam or is there another production cam?

I am alittle disappointed this is turning into a debate.

I having to say over again.................

Our approach has been to learn from folks that have a larger R&D ability than our own.
It has been that when you fix a design flaw,you just fix it.

We found the stock 4.3 has rods or pistons are offset to the bore.That depends on how you set that.

We found that doing research on what is different between the 4.3 and the 5.7's.

We found the split cranks are a weak link in the engine design.

All this was confirmed when(I HATE calling out names when having done that been there myself should be enough to just pass along the info),we bought a Bowtie cast block,common pin forged crank,aluminum 210 heads at auction st the Indy drag racers auction from NASCAR Henrick Motor sports.

What that does is provide a stroker set-up that cures the side load issues being the rods on a stock crank is offset to the stock crank in it's design.

For yrs a local machine that I am close to has told me about re-bores in bores that are oval because of that offset.

Now I wouldn't be doing my part on this forum if I didn't report what we know.

Are there stock parts that can be used??.Sure,I guess there are.I think the key here is to know as much as you can if that is the route you decided to take.Make no mistake about it,GM never intended the 4.3's to be a performance engine short of the turbo version they built.Just to say that the 4.3's are just a 350 with two cylinders cut out of it,well there is more to that to know and learn from.That is the myth I see all too often.That is just not true.

If your serious about a 4.3,I suggest you do a hard look at the link I left for this thread.Also,the marine parts are a good source for mods.LOL-as long as you don't hook up with a reverse rotation cam.

Originally Posted by sfort

Pat the cam you are talking about is it the 225hp cam or is there another production cam?

there are many cams made by many hyd solid . flat and solid roller and hyd roller . custom if they have cores .gm made many rollers cams and were made here in bay city