i got myself a 1976 455 olds engine and was taking it apart to go thur it
and i got one side of the exhaust off and found that there is a crack in it
about 2 inches long... was wondering if that can be fixed or if any other motors will use the same exhaust.... i do have a 4.3 V8 from a 82 cutlass .. will that fit? also have a 66 f-85 that has a 330 in it ... that is the car i want to put the 455 in???

any ideas??? thx

 

This is all going to depend on what you want to do with it. Ar you going to go dual exhaust or hook up a stock type converter to it?
If the latter is the case you will need the 75 ^ right side manifold due to the angle of the exit to the converter (90° down) and the 3 bolt flange.
If you are planning to go with a dual setup then I would suggest getting some W/Z 455 manifolds as they will flow better than the ones that came on the engine. They even make a set with 2½" outlets for larger pipes.

And don't even think about the 4.3 (260) manifolds. They are TINY.

 

I was just going to post a thread as to what, IMO, a crazy exhaust set up is on the '71 Olds 98 w/the 455. It's a single exhaust set up and the head pipe goes from the driver side manifold under to the passenger side and then the single head pipe exits the passenger side manifold. WTF!!! I know that system sucks up some power. When I pulled the engine and tranny together, I had to cut that head pipe on both sides and drop it, the head pipe bolts hadn't been out in 40 years, to get the engine over the front cross member at a low enough angle to get the trans tail over the trans cross member so as not to hang up. The engine came out easy enough, w/ the exception of that "under" pipe, but I feel that it's a crazy set up that I would have thought was "by the way side" by '71. That was used, but it went over the top, on the early '60s Ford V8. I'm ****-canning those manifolds f/sure. I was getting headers anyway, and if I wasn't, these manifolds would have made me go headers anyway.

 

Jim, that method was used for longer than you might think and I agree that it didn't make much sense. Besides being restrictive imaging all that heat radiating right into your oil pan......

 

Like I mentioned in my reply, I'd have thought that since the late '50s/early '60s, that this method would have been phased out due to inefficiency. I was really surprised to see it on this '71 98. The V8 that came in the '62 Ford pick-up, I'm thinking it was a 292-mine came w/ the 223ci 6cyl, has the head pipe coming over the top, and at my first sighting of it, I had to close my eyes and shake my head then take another look. Not just a crazy idea, but strange looking at that. I just can't see where there was money saved or any other reason f/ a mfg to produce such a thing. Although I'm sure there was some reason f/ it. Along w/ that manifold, the starter has a cover/shield on it and w/ the two, it's damn near impossible to get at the starter wiring. Even w/ the engine out of the car, the wire connections are untouchable w/o taking afew "super hard to get to" bolts off. Not a good situation.

As you said, the heat on the pan (and engine compartment as a whole) and inturn the oil and complete bottom end. And such a tight enclosed space can't be good f/ the starter either. I would have thought that an auto mfg would have opted f/ designs that would prolong and not reduce the life of their engines, atleast w/ something so simple.

 

Oldsmobile used the exhaust crossover on the 307 all the way until 1990. I had a 1990 Buick Estate Wagon with an Olds 307. It had a similiar crossover. In 1991 full-sized Oldsmobiles either used the 3.8L V6 in the sedans or the Chevy V8 in the wagons.

 

Actually, from a manufacturing standpoint this makes perfect sense. The crossover gets installed on the engine assembly line. When the drivetrain is dropped into the chassis on the main car assembly line, there is only one pipe connection to make. Less time, less labor, fewer chances to screw up.

 

You're right, Joe. And hence the situation that the American auto industry is in today. In the hole. I guess that I wasn't thinking the way they think.

 

If you absolutely have to have a exhaust manifold from a 76 455, I have one in my garage you can have. I would need to pull it from my spare 455 block but it is from a 76 455 delta with the crazy cross over pipe connection. I'm near New Haven, CT. Heck, you can have both sides.
Most people go to dual exhaust manifolds as stated above or headers and these go to the recycler.
You sure you don't want to eventually go that route?

 

i guess i am just trying to get sort a "cheap" older car set up
paid $375 for a pretty rusty 66 f-85 and then thought that being the car was going to need alot of work.. why keep it orignial and just a big olds engine in it ... so i found a 455 and a turbo 400 for $125... so i guess what i am saying i just want to get a car together for as cheap.. but some what relieable.. was hopeing to just go thur the engine with gaskets and stuff but ... that is what you get when you buy stuff cheap...

w/z manifolds for 72? those work... Thornton reproductions????

 

Airlamb don't get me wrong because i love my olds, but cheap is the furthest from what olds is. IMO for the price you paid you got ah deal. I paid $600 for my 1976 455 and th400. Mine was neither rusty or a lot of work since the car it was pulled out of was driven up until that point. PM me with what you need i still have a few things that were stock on the motor that i just have laying around. And i'm almost sure i have the same manifolds laying around also. Good luck on the rebuild.

 

They bolt on really nice you just have to have custom pipes made due to the angle of the outlet on the passenger side being different. Not that big of a deal for a muffler shop. They might make you put some cats on it though so check around.

 

I know that in California, pollution devices are a must wherever you go, and I always admire the guys out there in the land of custom cars, who play by the states emissions/safety rules and still turn out some incredible rides. I know here in Texas, if you want what the shops call, an off-road exhaust system, they'll install it, just as the after-market companies sell them f/ that purpose.
I also agree w/ the former post about Olds rides not being cheap. If you want something cheap, go f/ an older Chevy w/ a small block. It's always been that a Chevy is cheapest to build, then a Ford, and a Chrysler product is a high dollar venture. I think the Olds falls inbetween the Ford and Chrysler. But I picked the Olds 455 because it's different, and the guy next to me at the light probably doesn't have the same thing I have. The older "nailhead" motors are very popular now f/ street rods, as they were years ago, but I didn't want something that would cost me mucho money and still not have the power I want, so I went w/ the big Olds that's different, a modern design, and makes good power.

***I have to say that I'm surprised that someone, Edelbrock or another a/m company, doesn't have a set of aluminum heads f/ the BBO that run to the best of their ability out of the box. There must not be enough money in it. In comparison, AFR has heads f/ the (all-out and 3 steps down)SBC that flow to the best of their ability out of the box, already taken to the limit by the company. When I first read about the Edelbrock aluminum heads, it was like I went back 20 years when you were better off buying aluminum heads bare and installing good hardware after machining them f/ your application. Ofcourse there may be just a touch of work you would want to do to any top end components if you're running f/ the record, but f/ 98% of us, there should be a set of heads out there that you can bolt on and know that you have 99.8% of what it takes. Like I said, must not be enough money in it, otherwise I'm sure they'd be out there to be had. I've also come to the conclusion that I'll get the most bang f/ my buck using mildly worked factory cast heads, as after you start spending what it cost f/ aluminum heads and working them, and buying the needed components that work well w/ them, the dollar amount per hp starts going way up. But, even w/ the cost of building the BBO, you still have something different than most, and that in itself is a good enough reason. "LONG LIVE THE BBO." Having been a Chevy Man all my engine-building life, The BBO, which I've only recently become familiar w/, is a really cool engine which I'm really excited about running.

 

That is a great letter. I agree the whole way. We need "the easy to get goood! heads", Why doesn´t edelbrock make the cylinderheads for a small block also, smaller combustion chamber etc. I have been a chevy guy all my life, until I swapped in a olds Cutlass 442. Now I´m becoming a oldsmobile neard because it´s more fun, more educating, more frustrating, more expensive (bad part), more challanging to do the olds. It´s fun to do something new and different. I live in a small community. I would be happy if I see 3 oldsmobile cars at a Cruise night compared to 55 Camaros,
53 Mustangs 45, Chevelles, You get it?

Regards
Stanley

 

Have you seen how they run the exhausts on some of the mid 90's Cadillac Northstar engines? What a fiasco.
What is worse is the heat crossover in these things have 4 cylinders heating the intake manifold to just around 800 degrees F. Enough to cook the oil under the manifold, and the 4 center pushrods until the rockers starve.
Fill the crossover, dual exhaust.
I still love the look of stock exhaust manifolds.
Jim

 

I've got a N* in my 93 Allante and I'm not sure what your point is. This exhaust system supports 300 HP (net) from 4.6 liters. Considering that the last 455s only made 250 HP net, where's the problem?

I assume you're no longer talking about the N*, which does not have a crossover or pushrods.

 

But understood, the Union at work.

 

I'm not getting it. Does the Allante have the cross-over on the 4.6?

 

Joe I was referring to one of the full size Cadillac's I had worked on (not sure of the model anymore) that routed the exhaust over the transaxle. I was aghast.

The crossover I alluded to is the heat crossover in the Oldsmobile V-8 engines that continually cooks the lower part of the intake manifold.
Sorry for the lack of clarification.

All of these things definitely can be handled, not everything built is the way we expect it to be, but are made with a wider range of concerns that we may not be aware/concerned with.

I too, hope that Edelbrock works over that casting a bit, to make it work on the small block efficiently, considering that the stoutest block Oldsmobile ever cast, was the Diesel block.

As per the topic, finding another manifold will be less expensive than welding. Do anything you can to lessen heat in exhaust.
Good luck,
Jim
Jim

 

u can still get the right side down pipe from car quest for dual exhaust