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chanan

1970 455 pontiac engine

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Good day members,

I have a 1970 455 pontiac engine that I would like an idea of the value. The engine is complete with all accessories,carb,dist, etc. and is turns freely.

Any info will be appreciated.

Thank you

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The value of 455,s is very dependant on which version the particular engine is. There are several diferent head castings used along with other parts. The value can range from not a lot more than scrap for the base model engine, to very valuble indeed for the top hi performance version. You need to dig deeper and find out exactly what you have before anyone can sugest a value.

All the best Greg

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Any 455 in good condition even the base 360hp with the small valve # 15 heads & 10.0 to one compression is most certainly not scrap. The higher horsepower and larger valve heads are more desirable, but in any case won't work with today's wizz bang gas. If you want to drive with Today's gas you either have to use dished pistons or change to another head like the 400's 7K3 to get the compression in the nines to prevent detonation. any 455 block in good condition is a welcome addition.;)

D.

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Any 455 in good condition even the base 360hp with the small valve # 15 heads & 10.0 to one compression is most certainly not scrap. The higher horsepower and larger valve heads are more desirable, but in any case won't work with today's wizz bang gas. If you want to drive with Today's gas you either have to use dished pistons or change to another head like the 400's 7K3 to get the compression in the nines to prevent detonation. any 455 block in good condition is a welcome addition.;)

D.

Can't a additive be used to boost octane?

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Can't a additive be used to boost octane?

_________________________________________________________

Sure, if you can find something that really works. Before I put 7K3 heads on my 455 in 1992, I had to use five gallons of 100 octane fuel to fifteen gallons of 92 pump gas to prevent detonation....that can get expensive, but less expensive than the additives that are in the auto parts store which don't work. When I installed the big valve 7K3 heads ( 400" heads with 96 cc chambers) it eliminated 95% of the detonation. I still get some detonation (the other 5%) on very hot days and low humidity at wide open throttle. those heads decreased my compression to 9.5 to one. The other remedy would be to go with aftermarket aluminum Pontiac design heads from Edelbrock, Wenzler, or kauffman. With aluminum heads you can run about a point and a half higher compression than you could with iron without fear of detonation----that's one of the reasons all new cars have aluminum besides the weight reduction. I might add that everything for the Pontiac engine including Iron and aluminum blocks, heads, cast and forged steel cranks---everything internal is being made in aftermarket and all parts interchange with original Pontiac components.

D.

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_________________________________________________________

With aluminum heads you can run about a point and a half higher compression than you could with iron without fear of detonation----that's one of the reasons all new cars have aluminum besides the weight reduction. .

D.

Back in 1986, when the Corvette factory aluminum heads came out, I bought a set for my "in process" 350 +.030 engine. I picked the '71 350 pistons to go with the smaller chamber volume of the Corvette heads. I figured it made about 9.5 to 1 compression ratio. I was hoping that I could get away from using super unleaded too, for the same reason mentioned . . . but it didn't work that way. I was using a Cam Dynamics Energizer 266 cam (210 degrees @ .050, .440 lift), for the record. After we got the engine installed, I first put some miles on it beforre I started tweaking the ignition timing and such. With the igniton's base timing set at 10 degrees BTDC, it needed 93 pump octane super unleaded to be quiet. Even a 50-50 mix with mid-grade resulted in trace rattle under hard part throttle. When I tried straight mid-grade, just a few pump octane number less, it rattled worse! So, the theory of being able to buy gas for a 8.5 to 1 compression ratio, yet with a figured 9.5 to 1 cr on aluminum heads, just didn't work that way for me.

Almost all later model engines do usually have aluminum cylinder heads. Weight is certainly a consideration, as machining ease might be another. But I suspect the real reason might be that aluminum heats up quicker than cast iron on a cold start . . . thereby reducing possible hydrocarbon emissions during the cold start testing cycle. I know that I got hot heater water on my Camaro a good bit sooner with the aluminum heads compared to the prior cast iron heads.

One reason that turbos had a temporary disappearance from the marketplace was that the turbo was a big "heat sink", which affected the engine's capabilities of passing the cold start emissions test cycle, which tended to delay getting the catalytic converter to get up to its fully-functional operating temperature. One reason that 4 valve/cylinder heads and superchargers suddenly came to prominence. When the cost of the heated oxygen sensors became more reasonable or "coverable" by engine option costs, the turbos reappeared.

These were just my own experiences. No more, no less. Perhaps others might have had different experiences?

Regards,

NTX5467

Edited by NTX5467 (see edit history)

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Sorry Helfen , I diden't mean to say a 455 is suitable for scrap, however the value of a base 455 core engine is not very high. They can be at times dificult to come by, but with patience they appear at quite a reasonable cost. When I have needed a big GM core engine I look for a good running full size car. I then harvest the engine and sell off what little I can of the rest of the car. Unfortunately there is little demand for parts from these cars so I have little choice than to scrap them. The up side is with scrap price as high as it is the core engine ends up being almost free. This works well for Mopar 440's, Ford 429's/460's GM 400, 454, 455. etc. Most of these engines went into full sized cars, pickups and motorhomes. Now that they have outlived their first life it is good they can go on to a new life in a muscle car.

Most people around here just take these vehicles complete to the crusher. I think this is a crime when good core engines are involved.

Greg in Canada

Edited by 1912Staver (see edit history)

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Thank all for the input. Block and head numbers will be posted tomorrow. Sorry don't have a clue on the miles. I've had the engine for some time now and I'm trying to scale down on projects.

This, along with a 67 GTO project will give me more room to finish other projects.

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Back to the 1970 455.

The engine code is 0521182 YH front of block and 9799140 on the rear of block.

Head numbers need to be cleaned up in order to get a good reading.

Thanks

Robert

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Back to the 1970 455.

The engine code is 0521182 YH front of block and 9799140 on the rear of block.

Head numbers need to be cleaned up in order to get a good reading.

Thanks

Robert

_________________________________________________________

The 1970 455 YH block is the 360 HP with 10.0 compression small valve 1.96/1.66 with a head cast of #15 on the top of # 3 and 5 exhaust port on the left side of the engine, and on the rt. side on top of the exhaust port of # 4 & 6. this engine comes with the 067 camshaft. Also, these later open chamber heads including the 350 engine still have bigger intake valves ( 1.96 ) than the early Super Duty big valve Heads ( 1.92) for the 389 in 60-62.

The 421 Super duty has smaller valves ( 2.02 / 1.76 ) than the high performance 350, 400, 428, and 455 high performance engines which are 2.11 / 1.77.

Just a interesting note, the 350 Pontiac engine is really a 355, the 428 engine is really a 427, and the 455 is really a 456.

The original 1963 326 engine is really a 336. In 1964 it becomes a 326.

D.

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Thanks again for the response.. Were these differences during the DeLorean, Estes and Knudsen years when they were trying to slip things past headquarters? Do you have a idea on the value.

As I said before the engine is completely trimmed and free. I have a young man paying his dues as an engine builder and I want to be fair with him and myself on the price.

Thanks again,

Robert

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Thanks again for the response.. Were these differences during the DeLorean, Estes and Knudsen years when they were trying to slip things past headquarters? Do you have a idea on the value.

As I said before the engine is completely trimmed and free. I have a young man paying his dues as an engine builder and I want to be fair with him and myself on the price.

Thanks again,

Robert

_______________________________________________________________

Robert, I also have a complete 455 Pontiac that I have kept as a extra, it came from a good running but trashed body 71 Bonneville. Just me saying now, I wouldn't let that engine go for under five hundred...that's just a rebuildable engine were talking about and the heads on it have too large of chamber volume to be of any use to me.

The engine differences under leadership vary. The 326 was most likely under the guidance of Knudsen, but Knudsen was promoted from Pontiac to Chevy in the fall of 61, but the design of the 63 cars were partially under his watch. My guess is that Pontiac was unaware that there was going to be a engine size cap for the newly introduced intermediates for 1964. When that edict came out Pontiac had to make the 336 a true 326. The limit for those cars was 330 cu. inches.

As far as the 428 goes, after the GM ban on racing in 1963 I think Pontiac thought someday it might be lifted so they could race again, and at that time NASCAR, NHRA, IHRA, had cubic inch limitations of 427 inches... that is why I think the 428 Pontiac is a 427. The other two engines 350 & 455 were named that way possibly because it was a nice round number.

If you want/ need more information like; why did the 389 become the 400 and why did the 421 become the 428? just ask.

D.

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I have found a 1970 Pontiac ambulance with a 455 engine is there any thing

special about this engine??

Should I get it? the overall condition of the ambulance is poor to awful.

I am thinking of salvaging the power train.

Is this a worthwhile endeavor.

Thanks in advance.

bill

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I have found a 1970 Pontiac ambulance with a 455 engine is there any thing

special about this engine??

Should I get it? the overall condition of the ambulance is poor to awful.

I am thinking of salvaging the power train.

Is this a worthwhile endeavor.

Thanks in advance.

bill

YES!

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IMO the 1970 455 is the pick of the litter among regular production Pontiac V8s. For anyone building a Pontiac street machine this engine is a great find, if it were in my area I would pay at least $500 for a complete rebuildable one. Just one man's opinion but the comments above seem to agree, Todd C

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IMO the 1970 455 is the pick of the litter among regular production Pontiac V8s. For anyone building a Pontiac street machine this engine is a great find, if it were in my area I would pay at least $500 for a complete rebuildable one. Just one man's opinion but the comments above seem to agree, Todd C

I agree with Todd, and with each year fewer and fewer remain. Also latch on to that long tail shaft T-400 too! Guess what, if that car has rare disc brakes option that I believe are only 69-70. 1971 up to 76 are different. So grab the brakes, and front spindles--those two go together and can be used on early cars. My 62 Catalina has those brakes and with the tall spindles and fitted to the early cars you get the bonus of negative roll steering which really wakes those cars up in the handling department and they don't wear tires out as fast either.

D.

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the 1970 455 is the only year high compression 455, in a full size pontiac, the 4bbl horsepower was a stock 360 horses, in a gto, it was 370 horses. the motor is worth it's weight in gold. don't pass it up. charles coker, 1953 pontiac tech advisor.

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Thanks for the info.

I guess it's time to talk to the owner.

BTW this car is in so. cal. near San Diego if some one else would be interested I could put you in contact with the owner.

bill

Edited by bills999 (see edit history)

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Thanks for the info.

I guess it's time to talk to the owner.

BTW this car is in so. cal. near San Diego if some one else would be interested I could put you in contact with the owner.

bill

Bill, if you don't really want the car or it's contents I think you should contact the people of the San Diego or Southern California chapters of POCI. It's important that either the whole car or it's parts are saved.

Don

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Thanks for the info.

I guess it's time to talk to the owner.

BTW this car is in so. cal. near San Diego if some one else would be interested I could put you in contact with the owner.

bill

Bill, if you don't really want the car or it's contents I think you should contact the people of the San Diego or Southern California chapters of POCI. It's important that either the whole car or it's parts are saved. If you want PM me and I can put you contact with a friend of mine who is president of POCI.

Don

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