bobs83hurst

Good morning all I have a 455 i bought 2 years ago and put into my 83 hurst. I can't find anyone who knows exactly what i have so hoping some of You will know. I bought it as a 70 motor with 90,000 miles on it. This is what i have for numbers on the motor. the carb number is 7040159 I've been told olds never made a 455 with a 2bbl carb but that's what i supposedly have here. Any help? Thanks

70cutty

If you search engine decoding, or engine id in the SEARCH box towards the top of your screen or Google, you will find at least 100 threads with answer and instructions on where the block vin derivative numbers and head numbers/letters are, as well as how to decode them.

tru-blue 442

Olds made a lot of 455 2 bbl. engines.
Yours is for sure a 455. If a 70 model
original, it should have E heads on it as well.

Here is a few pics of a 70 core i have
sitting in the back yard. The only difference
is the carb on mine is a 7041054.

This engine came in a 70 C/S and even
had W/Z manifolds from the factory.

MDchanic

And whoever told you that is, of course, an idiot.

This is a 1970 Olds 455 with a 2bbl Rochester 2-Jet carburetor.

There were two versions made:

• 10.25:1, dual exhaust, 320hp / 500 ft/lb L33, optional in Cutlass, and
• 9:1 single exhaust 310hp / 490 ft/lb L30, standard in Delta 88 Royale and Custom

All of this information is available in the 1970 SPECS Guide.

- Eric

70cutty

You can try here too.

http://442.com/oldsfaq/ofeng.htm#ENG...20Block%20CIDs

MDchanic

Yes, but only if you bear in mind that the "OldsFAQ," like the Hitchiker's Guide to the Galaxy, "... contains much that is apocryphal, or just plain wrong..."

- Eric

bobs83hurst

Thanks all of You. It's nice to have someone who knows what they're talking about. True blue it does have the E heads on it. i'll say one thing it sure makes the lightning rods a lot more fun. Would it make sense to put a 4 barrel on it or just leave it the way it is?

MDchanic

You can see both the E heads and the 1970 engine number in this picture:



You would be likely to have increased performance if you added a 4bbl (and manifold) to this engine, ASSuming you also have dual exhausts, but it won't be a night-and-day change unless you drive with your foot close to the floor most of the time.

- Eric

bobs83hurst

i did put dual on it and it ran a bit better and has a nice sound to it. It sure beats the 307 that wouldn't even spin the tires in dirt. It had been rebuilt and i was told if not done right i could have less then 150 horses in it.

tru-blue 442

Did you have the trans reworked?
Be easy with it, it will be next if
you do go 4 bbl.

bobs83hurst

i had the tranny rebuilt by Atlantic transmissions in Amesbury mass. They told me it could handle the 455 easily and much more. My only thing is it takes too long to shift from first to 2nd and I have to let up on the gas to make it shift. When I use the lightning rods it shifts great.

w-30dreamin

It would make perfect sense to put a 4 barrel on it,you will notice a difference.
I've read where people say you'll get better fuel mileage with a 4 barrel as long as you stay out of the back 2 barrels.But...who cares about fuel mileage,it's a 455 and who can stay out of the 2 rear barrels with a 455?

With the 2 barrel and regular valve covers(without notches),I would say this is a low compression,small valve 455 from a big car. Still alot of fun though!

MDchanic

I agree that that is most likely the case, but if, as you say, it was "rebuilt," its present compression ratio would depend on what pistons were put into it, and what sort of head gaskets were used and what machining was done.

You could have a 10.5:1 motor or a 7.0:1 motor.

Then the question of what sort of cam is in it comes up...

- Eric

bobs83hurst

I have the manifold for the 4 barrel. When i bought the engine the guy who put it in changed it to an edelbrock 650cfm but I was told it was too small for the motor so i put the 2 barrel back on. I never did understand how any 4 barrel could be too small for an engine that had a 2 barrel

bobs83hurst

I should explain it was the 307 rebuilt not the 455. my bad

tru-blue 442

Depending on the vaccume modulater that
is on it now, inside where the rubber line attaches,
there is a small screw that you can turn in or out
to adjust the shifts some, if I recall correctly.

w-30dreamin

And I do agree with you, if it were rebuilt all you mentioned is true.
The Op mentioned he bought it as a 1970 motor with 90,000 miles.

tru-blue 442

Ha ha, now he tells us it's the 307.
You bad, Bob.

bobs83hurst

i haven't even had my first Easter drink and I am confusing everyone. The 307 was rebuilt and that is why i bought the 455 for 500.00 and had it put in. Gonna be a long day. Heading to sons house for dinner so be back later. Enjoy your day all

oldcutlass

I would think that if it runs well on the 2v, that it would run just as well with the Edelbrock.

MDchanic

Ahhhhhhhhh... Now I understand.

Yes, it is probably the low compression 455, but, unless you know about the car it came out of, there is a chance that it could be high compression.

Either way, a 650cfm carburetor will make it faster than the 2-Jet, which had somewhere between 350 and 435cfm, depending on configuration (probably 435, and, no, I'm not looking it up... ), at 3"Hg.

Also, for that motor, in the RPM band it would be expected to work best, a 650cfm should be just about right.

- Eric