MoTie

Hi all, I've came across a 454 BBC and th400 out of a '76 rv with 70k on the odometer. It runs but could definitely use a tune up and some fresh gas. I can buy both for $160.00 and I pull them. My question is however, is it worth the price being a motorhome engine? And are there major differences between the rv 454's and high performance 454's, as side from being low compression smog engines? Would this be a 4-bolt block and steel crank? I'm more familiar with gen 1 sbc's so sorry for my lack of knowledge on the subject.

DeltaElite121

$160 is CHEAP. I'd get on that QUICK. You can make some good coin just flipping something like that if it runs good once you get everything set up.

s10sbc350

Even though it's from a RV if it's an 80s model they had like 245hp stock and around 360ft-lbs of tq... Not exact but in that area, and while that's not much considering the cost to swap plus added weight... The bb will hold more power and you could spray it's *** off with some N2o. Also a built BBC would cost you a lot so why not just build this RV motor to exactly how you want it... Because a already built one sure isn't gonna be your perfect world type of motor JS

MoTie

Right on. It could use some tlc, but overall the engine looks pretty clean considering its just been setting in the guys back yard for a couple of years. The oil and coolant looks like it had been changed a week ago! I'm thinking with some new plugs/wires, maybe a cap and rotor and fresh gas that thing would probably line right out. It started up easy enough (with a little starting fluid), although I could hear a slight miss in the ignition timing. But nothing too consistent though...

MoTie

Thanks, good to know it would be a viable candidate for a performance build! I've had a few mice, I think I'll try the rat out and see how I like them Time to do some searching for BBC swap info!

AlkyIROC

BBC swap info is a sticky at the top of the engine swap forum

MoTie

Much appreciated! I'll check it out right now

MoTie

BTW, can anyone tell me what a built (500+HP) BBC is like in these cars? Especially compared to the stock SBC in which they came? I know my stock trans and rear end wouldn't last long with that kind of power, I eventually want to go to a th400 or PG and a Moser 9". I'm just trying to gather what the sheet of the pants performance would be like in a third gen that puts down 500 (or better) whp. Not that going from a bone stock LG4 to a built BBC/supporting mods isn't going to be largely noticeable. I know some of you guys are running some seriously powerful engines in your third gens with the E/T's to prove it!!!

MoTie

AlkyIROC you seem to have a wealth of knowledge on these cars from what I've read on this forum!!! Nice Iroc BTW Your website is very informative as well!!!

s10sbc350

Well just wanted to say this. After you swap in that BBC motor it's gonna add more unwanted weight to your front end... Which in a 500+ Hp third gen it wont help much with a quest for traction and low 60ft times.

So maybe consider getting a tubular K-member, relocate battery to the trunk, and maybe deleting your A/C "If your weather permits " Which should all help your 60times drop and be more consistent.

MoTie

I've been kicking the idea of a tubular K member around for a while now, how good are they on the street strength wise? I'm looking to build the car mostly for the strip although I'd like to be able to drive it to/from the track. I've already gotten rid of the heater and A/C a while back (I don't mind the lack of creature comforts). Also I've read that I could also drop some weight with aluminum heads, intake, and aluminum water pump, or electric water pump. Idk exactly how much weight an aluminum top end would save me over iron, but I'm inclined to believe it would have to be a substantial amount considering the materials from which they're made?

s10sbc350

Well a set of Aluminum heads would drop 25-50Lbs off the front if I remember rite, but a electric water pump wouldn't "IMHO" be worth the $400 for a few LBS.

Also a tubular k-member isn't as strong as the stock one BUT I think one should still be fine for a 500WHP app. Another guy that's more familiar with BBC motors will need to chime in on that one.

MoTie

25-50 pounds off of a BBC would be nice! Also I don't see why a tubular K member wouldn't hold up to occasional street use? And an an aluminum belt driven water pump does sound more feasible.

MoTie

This K member should be strong enough for my intended application, http://www.racecraft.com/index.php?m...3f60ace1cc406d

MoTie

I also purchased that engine and trans, now to break out my trusty 'ol shop crane that's accustomed to pulling SBC's and use it to get the fat rat loaded up into my truck tomorrow I got both of them for $160.00!!! The previous owner was just going to scrap the whole thing so I made my offer and he said I could have the trans too! Time to get dirty!!!

8Mike9

There's only around a 100lbs difference in weight.

Al heads (not cheap, but)...and an AL intake along with headers vs manifold on a SBC...your pretty darn close in weight.

PS

Good buy, BTW!

MoTie

Thanks! Glad to know I can shave a few pounds off the 'ol BBC! As long as I can get it into the ballpark of my all iron LG4 I'm happy!

s10sbc350

ONLY a 100LB difference??? IMHO That's enormous when you add 100LBs to the font end of a car that already doesn't have good front to back weight distribution.
Also headers might only drop a few LBS but Aluminum heads, lightweight radiator, A/C delete, Tubular k-member, Relocating battery, Lightweight LCA's, and removing the front sway bar will all make the cars weight distribution even out... And you'll have less weight on the front then if you had a SBC if you did all this.

MoTie

I've heard that removal of the front sway bar also helps with weight transfer, although I have no firsthand experience with this. And its good to know I can sort of have my cake and eat it too when it comes to having a BBC and being able to shed a few lbs!

MoTie

So with an aluminium radiator top end & H²O pump, and battery relocation to the rear. Would I be able to use the stock springs, or stock-ish spring rate in the front? Also, does anyone know how much HP the Hooker BBC swap headers are good for? Or would it be a better idea to just go ahead and pull the trigger on a set of Ed Quay or Lemons headers and save on the cost of both (hooker now-E.Q./Lemons later)? I like the price of the hookers, but the primaries look a lil small for even a built sbc. And I'm sure once I get going the performance bug is bound to bite me,so something with "growing room" would be nice for any improvements down the line...

s10sbc350

Yea removing the front sway bar helps somewhat with weight transfer and It's a good ideal to remove it... Unless your ever planning on taking corners hard with a drag car

s10sbc350

In all honesty I think a tubular k-member would shed a hair more then all those mods that you mentioned... Id do those things like lightweight radiator etc only if a tubular k-member doesn't shed enough off the front for your liking... And if your building a 500HP motor your gonna be doing head work. So that's when you should upgrade to the aluminum heads

8Mike9

I did mention Al head

The rest is to make his BBC closer to his LG$

Bet he save more weight with headers vs. Manifolds, than a lightweight radiator

AC delete...sure, but if he likes AC, ...

Easy to make 450-500HP from a BBC and 600-650 ft/lb and be very streetable, have ac and idle all day long in 100 degree heat.

I think my LS5 454 in my '57 was factory rated at 390/525...and this was 1970 tech...lol...love my AC, even after a few "upgrades"

AlkyIROC

Bone stock iron head SBC and BBC are about 100 pounds different. Changing out the iron heads on a BBC to aluminum and putting on an aluminum intake brings it very close to the weight of an iron head SBC so weight increase isn't really an issue unless you keep everything bone stock.

Two aluminum BBC heads weigh the same as one iron BBC head which is around 60 pounds. Aluminum heads are not exotic parts they once were many decades ago. A pair of oval port heads that are set up for the camshaft you intend to run are a very inexpensive option. You don't need rectangular port heads.

To help offset the cost, your donor mid 70's 454 should have untouched 781 casting heads. You could sell those for $200-$400 for the pair if they're in good condition.

A good SBC can make around the same HP as a basic BBC but the BBC's longer stroke will make a lot more torque plus it has a lot more potential. Doing an engine swap is only a small part of any conversion. Don't expect the stock transmission of differential to last. Using the TH400 requires a few modifications since you need some place to attach the torque arm plus the transmission mount will be in the wrong location. Both of these issues can be fixed with an aftermarket torque arm system design to be used with a TH400. While you're at it, you might as well invest in a new diff unless you plan on granny driving the car. You can estimate a bare minimum of $1500 to put in an aftermarket diff. You could also spend well over $3000 for a complete diff.

My car is far from stock or street legal so what I've done to mine isn't really what should be done to a street car. Even with all the weight reduction, my car is still nose heavy but that didn't stop me from putting it on the back bumper twice when track conditions were excellent one day.

MoTie

Nah, I'm not interested in corner carving. I basically want to build a semi streetable drag car. I'll leave the cornering for the import guys who think they are the reincarnation of Paul Walker
So they can "validate" (in their own mind) their 16 second accords as a "race car" in some aspect of racing, albeit even if its only limited to roll racing illegally on the freeway with no actual corners involved...

MoTie

Thanks for the info and for telling it like it is! This is exactly the kind of stuff I wanted to know! I would imagine my drivetrain would need swapped out for stronger components, not to mention I like the peace of mind of doing it right the first time I'm not big on having things come around and bite me in the @$$. Not to mention I don't want to cut any corners either!

s10sbc350

JS headers are a given mod when reaching out for 500whp (560ish crank) but yea your rite headers would shave more.

s10sbc350

AlkyIROC

You'll have to consult with other who have done the BBC swap into a street car. Header choices are very limited because the third gen body design doesn't leave a lot of room behind or beside the engine for a generic header. The cheapest set designed for the swap are from hooker and they're also the worst fitting.

http://www.jegs.com/i/Hooker+Headers/520/2226/10002/-1

With 1-7/8" primary tubes and only 3" collectors, the 454-502 claimed range is about all their good for. They're a street header. For high performance, you would want a 2" primary and 3-1/2" collectors which means special order or custom build. Keeping the displacement below 502 and keeping the rpms below 6800 and the street header will work just fine for most applications.

My race car uses Ed Quay headers. 2-1/4" primary and 4" slip on collectors. My headers are coated and worth around $1500.

Trying to use an OEM cast exhaust manifold is even worse. The ones that are on your engine will not fit without a lot of firewall modifications.

MoTie

So if I build a 496 out of it a set of hookers would work for a while, until I buy a set of Ed Quay headers? In the event the HP bug bites me...

AlkyIROC

All depends on your rpm range. A high reving large displacement engine needs to breath. I only spin my 588 up to 7400 although the camshaft grind says I can take it to 8000. The internal components can go to 8000 but they'll live longer at lower rpms. The way my car is set up, shifting at 7400 gives me a perfect 1/4 mile run. I'm out of gear and just past the shift point as I cross the finish line. Bringing the shift point higher means I would need a deeper gear in the diff.

A smaller tube header will help build some torque by slowing down the exhaust flow but too small a tube can be restrictive especially in the higher rpm range.

I ran the Hookers on my small BBC (454 + 0.070" overbore) and they worked fine. When I went to a 540, that's when I invested in some bigger headers.

Ed Quay
Lemons
Headers By Ed
Stahl

Lots of good aftermarket choices and none are cheap. Most also don't offer a swap header so it would be a custom order or build kit. My Ed Quay headers are first generation. Their latest generation is a completely different design. The #6 tube now wraps around under the frame rail instead of on top of it to get the proper length.

MoTie

Those Ed Quay pieces look nice. That's one helluva set up you're running!!! The hookers should work for me, I shouldn't have to spin it to the moon to make the power I'm looking for at the moment. Although eventually I'll be picking up some better headers when I need them

AlkyIROC

I bought my car in 1999 as a street car with an old school 383 stocker in it and I've never driven it on the street. From the day I bought it, I started gutting it out to be a race car.

The one thing about my car is that no matter what kind of changes I've done to it, it's still a production car. It even has a VIN tag still on the cowl. To get to where I am now and all the money I've spent, it would have been easier and cheaper to just build a tube chassis car.

I can't see going any bigger on the engine. Technically I could push it out to 605 CID but that's the limits of an aftermarket short deck block. It's easier to make displacement with a tall deck block.

My speed is also brute HP. No turbos, no nitrous, no blower. I run injected methanol alcohol for fuel and I'll never go back to gasoline and carbs in a race engine. Even it I was to build a new vehicle that only ran 12 second 1/4 miles, I'd still use injected alcohol. I run dual 4.1" flying toilets on the 588. That's 3600 CFM going into the engine.

But again, don't use my engine as an example for your own build.

MoTie

That's a wicked Iroc to be rockin out those E/T's all motor man!!! I was checking out your back half info on your website too, damn good job BTW! That car looks mean with those big slicks tucked under it

DeltaElite121

If you need a set, I could have my fabricator build you a pair to your specifications using my car for fitment/testing since it still doesn't have a motor in it (that and my car will be over there for headers soon anyways). He charges $650 a set for custom headers. Here's a recent pair he did for my friend's S10:




He did the whole cage and rear for my car as well, and did an excellent job.

MoTie

It will be a while before I need them as I don't even have the engine built and swapped in yet, but is there a way I can get ahold of you down the linen when I'm ready to upgrade? (Phone# or email?)

MoTie

Looks like he knows what he's doing too!

DeltaElite121

I'll PM you my information, sure. He likes to take his time, but he does a REAL good job. If you need other pictures just let me know and I'll post a few of my car so you can see the other stuff he's done with it. He's done several sets of headers for friends and they've all come out really well.

MoTie

Thanks! And I have no problem with him taking his time, can't rush perfection!