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I am looking to build a street driven 455 with dual quads.
Not looking to go full race, so iron heads and pump gas. Will be backed by a Turbo 400 and burning tires with a Chevy 12 bolt with 3.91 gears and 295/50-15 tires.
Car will have PS only, no A/C or PB.
I am thinking around 10:1 with Ka heads. Dual 600 carbs and a simple electronic ignition.
Want it to look old school, nothing fancy!!
I could use the Olds experts to chime in....................
If you want a dual quad 455 with good street manners, I'd strongly suggest searching for one of the long-out-of-production Edelbrock dual quad intakes for a BBO. These are the only dual plane dual quad Olds intakes. I ran one on a street 455 years ago and got over 14 MPG in a 1971 Cutlass. Be sure to use a progressive linkage on the carbs.
Unfortunately, the E-brock can be hard to find, but they do come up for sale every so often. The Offy dual quad intakes are still in production, but your only options are the single plane 360 version or the goofy 180 version. The latter is divided down the middle, so effectively you have a single plane intake feeding the right bank and another feeding the left bank. The two sides don't communicate, and since the firing order isn't R-L-R-L, the pulses are not equally spaced. There's a reason why no other manufacturer in history has ever made an intake like that.
Of course, if you really want bling, you could look for one of these :
Hello everyone, I recently picked up a 455 motor at an estate sale. I bought it without knowing any details of the internals. The motor was built for a boat but I jumped on it and bought it anyways. My plan is to tell the intake, headers and other boat specific parts and throw it in an olds.
Look again. As I said above, the out of production E-brock is the only dual plane dual quad intake for a BBO. Offy makes two dual quad intakes, the single plane 360 and the goofy 180, which is what you have linked. Again, the 180 is not a "dual plane", at least not in the conventional sense. The whole point of a dual plane intake is that the runners are configured so that successive cylinders in the firing order draw from alternate sides of the carb. For the 1-8-4-3-6-5-7-2 firing order, cylinders 1, 4, 6, and 7 draw from one side, and the others draw from the other side. Pulses are evenly spaced: 1-x-4-x-6-x-7-x and x-8-x-3-x-5-x-2.
On the Offy 180, the intake is divided down the middle and you have the RH side of the carb feeding the RH cylinder bank and the LH side feeding the LH bank. Instead of evenly spaced pulses, the LH side of the carb sees 1-x-x-3-x-5-7-x and the RH side sees x-8-4-x-6-x-x-2. Why this is a good idea remains a mystery.
Another thing to point out is that the Offy low rise offering pulls from left and right as Joe stated, it has a divider between the halves. The high rise version is basically a spacer attached to the carb pad which allows flow to be shared right and left.
I always found Offy to be a bit gimmicky.
Another thing to point out is that the Offy low rise offering pulls from left and right as Joe stated, it has a divider between the halves. The high rise version is basically a spacer attached to the carb pad which allows flow to be shared right and left.
I always found Offy to be a bit gimmicky.
Even worse it that the Offy is really just a big flat plenum with no apparent attention to mixture flow or velocity. I've found that the best use for the Offy intakes is to mill the carb flanges flat and weld on an aluminum plate to mount a 6-71. This is how most Olds blower manifolds are made. Note that this one started life as an Offy 180, as evidenced by the milled down center divider.
Totally agree with above posts to this thread in regards to dual plane vs single plane intake advantages/disadvantages. I know euroman1959 is looking for something old school and similar to what I have. So here is my story .....
I am running an offy dual quad, single plane 360 intake on a 455. I wanted a dual quad set-up and didn't have much choice with intake options at the time and no E-brock dual plane intakes were available when I built this 455. The offy tunnel ram intake below I own was a consideration for the build.
However, I decided to stay with the single plane and add the offy cross ram adapters with holley 780 carbs. Quirky, odd, unusual and even gimmicky - YES. I had no idea how this set-up was going to perform but I like and wanted different. The offy carb linkage package I initially purchased for the cross ram adapters was too flimsy. Therefore, I fabricated a sturdier bell crank set-up pictured below to ensure the linkage was going to perform trouble free.
This intake/carb set-up, combined with the 455 build and drivetrain components will shred tires and chew-up pavement all day long. Idles fine, decent mid-range and plenty top-end. I went with a long shot and it proved exceedingly better than I expected.
Build with what's available today ... you can always swap out for a dual quad, dual plane intake down the road if you desire. Good luck!!
I am looking to build a street driven 455 with dual quads.
Not looking to go full race, so iron heads and pump gas. Will be backed by a Turbo 400 and burning tires with a Chevy 12 bolt with 3.91 gears and 295/50-15 tires.
Car will have PS only, no A/C or PB.
I am thinking around 10:1 with Ka heads. Dual 600 carbs and a simple electronic ignition.
Want it to look old school, nothing fancy!!
I could use the Olds experts to chime in....................
If this is for your 73 you must be talking about an aftermarket 12 bolt since no OEM 12 bolts exist for your car. Your original 8.5" is plenty strong and with the right pieces is better in some ways than the 12 bolt.
Ever wonder why performance guys don't runt dual quads? Because they suck. A well tuned 4bbl will feed any street engine. Dual quads is for show not for go.
The engine will NOT be going in my 73 V code Supreme. It would be going in a 70-72 Cutlass, thats how I will be using a Chevy 12 bolt rear.
I like the drivability of the Edelbrock dual plane manifold, and the choke would be nice too.
I have found an Offy 180 with dual Holley carbs. It had a well made adaptor plate made of a billet piece of aluminum about 1/2 inch thick. It is very reasonably priced, but I haven't pulled the trigger yet. Still hoping for the Edelbrock.
My sole purpose of the dual quads is for the 'WOW' when I lift the hood. The car will be plain and simple, nothing that would turn heads..........until the light turns green!
Found this engine, but it appears to be parts from several engines.
Block is serif F cast, F4, with 171 cast date. Has 4 speed boss and 32M571531 stamped on pad.
Crank is N and is drilled for 4 speed.
Heads are GA dated 158. Are heads big valve?
Engine has been reassembled without any machine work done. But seller says it needs minimum of bores honed because of pitting.
Came out of a 68 442 with a turbo 400 behind it.
Found this engine, but it appears to be parts from several engines.
Block is serif F cast, F4, with 171 cast date. Has 4 speed boss and 32M571531 stamped on pad.
Crank is N and is drilled for 4 speed.
Heads are GA dated 158. Are heads big valve?
Engine has been reassembled without any machine work done. But seller says it needs minimum of bores honed because of pitting.
Came out of a 68 442 with a turbo 400 behind it.
Decent parts for a rebuild?
From my own recent experience, you won't know much of anything about this motor until you get it disassembled. Does it have the original pistons? Those would be high compression, if memory serves. Has the engine been previously bored? 442.com says Ga heads are big valve but that site isn't always right. But those are '72 heads so that tells you that the motor has been pieced together.
Once I started getting into the guts of my 455, I started not trusting ANYTHING and replaced everything that could reasonably be replaced. I think all I ended up using was the block, the main caps, the rods, the front cover, the flex plate, and the ND crank. I'm glad I didn't pay much for it.
I spent $1800 on machine work alone. 030 over bore, decked, line-honed, rod recon, rotating assembly balance. I haven't added up my receipts to this point. I'm kind of afraid too, lol.
Good luck with your build.
You never know what you get from someone else. I bought a '64 Starfire with a "transplanted" 455 and Turbo 400. I was told it was a '68 455. I figured out it had J heads, HEI that came out in'74. When the heads came off, I could see the deep dishes in the pistons (low compression). All of that that told me it was a 1974 or later.
Either way, you'll know what you have when you're done. Good luck.
Ralph
i have an offhauser 360* degree single plane intake, its a single plane with a notched divider, i got it used but its never been on anything, im still not sure if im gonna use it ir not.
You never know what you get from someone else. I bought a '64 Starfire with a "transplanted" 455 and Turbo 400. I was told it was a '68 455. I figured out it had J heads, HEI that came out in'74. When the heads came off, I could see the deep dishes in the pistons (low compression). All of that that told me it was a 1974 or later.
Either way, you'll know what you have when you're done. Good luck.
Ralph
I was told that mine was a fresh rebuild but never fired. He had been asking $1,500! But I got it for $350. I knew right there something was amiss. He let me pull the valve covers and turn it over but that was all. There was red permatex assembly lube on the valve stems but when I got it home and pulled the pushrods, a black soot spilled out. I pulled the heads and the new rings had about a 5/16" gap, lol. Oh my. The cylinders had been poorly honed and were very tapered. This thing would NOT have run if he had tried to fire it.
I don't understand why some folks feel they need to be dishonest.
Just wanted to update as to the progress of my dual quad build:
Bought the Offenhauser dual quad intake with a pair of matched Holley 9776 carbs. Intake has a 'machine shop built' carb adapter to allow the Holleys to be mounted front to back, not sideways.
Found a 72 455 block and crank that was just machined, a Comp Magnum 270H cam, got a set of big valve C heads and a Mallory dual point distributor that I will convert to PerTronix.
Just this morning I picked up the illusive Edelbrock O65 intake!
Probably will be looking for some AFB carbs for it and will most likely be selling the Offenhauser setup. (Didn't think I would find the O65!)
Its coming along nicely, with the help of many friends here on ClassicOlds.
December 3rd, 2017, 10:46 AM
455 engine ideas wanted?!
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