bullet1

i have been looking for bb to put into my 71 cutlass to run with friends sb chevys.got a call from a friend had a guy that has a 425 pulled from a 65 starfire says rebuilt and blue printed?of course at first he said he had a 455 until i quized him a little.he said the valve covers said ultra high compression then i asked did it say super rocket answer was yes told him he had 425.anyways would i get good performance results from this engine or should i continue my search for a 455.i would like to get around 450 hp.engine was removed from i believe a starfire?story is that someone started a project lost interest sat in a guys garage never heard from the guy again they pulled motor and tranny complete and scrapped car.i think i can get it for around $400-500 complete engine trannny combo.
thanks for any info hard to get info on 425's

2blu442

Welcome to the site! I would ask about casting numbers/letters before deciding if the engine is a 425 or 455. Either of those engines would be an excellet platform to build on. The price sounds good for a runner, if it really has low miles on it that could be a very good price. I would want to see paperwork for what was done to it before accepting it as rebuilt and blueprinted though.

If you have time read through the threads on the Big Block section to learn more about them. John

88 coupe

What blueprint was used?

Depends on the competence of the rebuilder, and what blueprint he/she used.

What he said.

Norm

bullet1

guy lives real close to me so i think i will try to get there today or tomorrow.supposedly sent motor down south somewhere to be built?almost have to take apart to believe of course no paperwork.it was left behind several years ago?how would a person know if it was blueprinted or not?i have seen where builders mark blocks?will 455 intakes fit on these motors.he did say it was red?
thanks for help.

citcapp

I don't know in what context the term blueprinted is used in todays engine building but when I was a young man in the dark ages the term was use for an engine built to extreme close tolerances and the whole term was "balanced and blueprinted". I haven't heard that term used in a long time.

Unless you can get the original build sheet or talk to the builder you won't have any idea of what has been done to the engine. Pull the valve covers and oil pan if it was never run after the rebuild the oil should be super clean and the heads and bottom end should look like new

joe_padavano

Unfortunately today the term "blueprinted" has about as much meaning as "numbers matching" or "3/4 race cam". As noted, get the facts and the details on the build. If they are not available, assume the worst.

88 coupe

Close.

Engines were rebuilt to factory specs (per the "blueprint" dimensions that were used in actual production) for use in NHRA stock classes. This included taking advantage of any "tolerances" that might be helpful.

Probably coined by the same wannabe that started the 442 CI and/or 442 HP thing.

Since "balancing" is part of any quality rebuild, that part would be redundant. Sort of like saying "small block 350" or "2 door coupe".

Norm

citcapp

Your correct in your definition Norm, wasn't making a statement in supprot of the terms, but heard it a lot 30-40 years ago hanging around IRS (local race track) and machine shops. Now we use terms like" balancing the rotating assembly", etc. Just saying the terms were used by many engine builders and hot rodders who new what they were doing. At least I thought so. Times change and so have the definitions used to explain a process.

I just spent some time cruising some internet car sites and found the term balancing and blueprinting to still be widley used with an explaination similar to yours without the redundant part

Oldsmaniac

A recent post on this site by another user poo-pooed the 425 for a serious buildup, in this day and age. IMO the 425 will compare well to a 455 and I would not be concerned over the lack of 30 cubic inches.

bullet1

not sure how long this engine has been sitting around so i would probably tear down and check out anyways.i also have a chance at a 68 455 with c heads but im sure this would be a full rebuild.i just want to have the right setup so when i do this i will be happy with the results.may get both and combine the two sounds like the 425 crank is the one to have.c heads seem to be the choice heads.will the c heads fit on the 425?the 425 seems to be the one that revs a little quicker.like to show the chevy boys a thing or two.i have heard the term gutless cutlass enough through the years even though my 350 in its day may people think twice.have owned car since 85 first car i actually payed money for but it needs alot of tlc.
thanks again

bullet1

forgot to ask if i remember right the pulleys and brackets from my 350 will not work on 425/455.the 425 comes with all the brackets even air.455 has none.also will 425 brackets work on 455.

88 coupe

Which might be a better choice, would depend on the goal, the application, and the owners personal preference.

For most, if not all, of the posters on this site, it would not make any difference.

Norm

88 coupe

No one said you were.

I was simply elaborating on what you actually posted.

Same as "balancing", except it sounds more "official".

And many of those "changes" have been made by the wannabes I alluded to in my previous post. After a couple of generations, much their "BS" has been accepted as "fact".

Good sources of myths and misinformation. The same sorts of myths and misinformation that the folks on this site are trying to correct.

Also good sources of myths and misinformation.

Norm

Oldsmaniac

If the 425 is indeed of 65 vintage the C heads may cause pushrod clearance problems as the lifter bank angle is different than a 68 455 block. There is nothing wrong with using the stock A heads. However some early 425 heads had a different style rocker assembly and parts may be hard to get for these.

If you swap a 425 crank into a 455 you will need the 425 rods and pistons and then you will have recreated a 425 in a 455 block.

The brackets and pulleys from a 455 will work on the 425.

88 coupe

That is always the first step.

No way to know,until the "first step" is complete.


Unless one is "building" a full race (Serious racing) engine, the only difference is the strokes. If one is "building" a full race engine, an aftermarket crankshaft would be a better choice.

Yes. They are not much different than the A or B heads that came on the the earlier 425. If the block is machined for 45° lifters, the pushrod holes must be enlarged for clearance.

Since I have been on the internet, I have seen that posted. Possibly accurate, as long as it is in neutral or park. But if, with all other factors being the same, both were accelerating, how could a 425 "rev faster" than a 455?

Norm

cutlassefi

Norm. how do you know the 425 won't rev quicker, not just in park or neutral. Can you prove it or is it your opinion? Do you have the facts to back up your statement? Have you run this very test yourself? Where is the written proof for your statement? And who wrote it?

In theory, all else being equal as you said, the 425 will have a slower piston speed and therefore should rev quicker, less reciprocating inertia. Whether or not it's measureable on this combination is a different story, althought that can be verified on a dyno now. It's called "rate of acceleration".

88 coupe

How is that possible, when the rate of acceleration is controlled by the computer software?

Norm

88 coupe

I did not say it would, or that it would not.

Here it is, again:

If you had bothered to read it, before you replied, you might have noticed that it was a question, not a statement.

Norm

captjim

Definition "rhetorical question"
"A rhetorical question is one that requires no answer because the answer is obvious and doesn't need to be stated . The speaker (of the rhetorical question) is not looking for an answer but is making some kind of a point, as in an argument."

Norm, you are so obviously disingenuous that it is comical.

Mark, anything that has been written on the internet or bandied about at drag strips or in garages that Norm agrees with is "fact" while anything he does not agree with is "internet myth". Truth is there is more than one way to achieve a goal, and Norm does not understand that a fair amount of this hobby is opinion and can not be absolutely proven one way or another. It really is just a matter of personal experience and confidence.

This is how many CL members deal with him,
This message is hidden because 88 coupe is on your ignore list.

Jetstar-1

IMHO, I agree with Oldsmaniac, you have to watch what you're doing mixing parts with a 425 since it is a 45 degree engine. The big blocks were changed to 38 degree in 66 to fit in theToronado. There's also different lifter sizes to watch for in the Toro engines. I doubt the 455 intake will work. Do your homework, lots of info out there if you dig for it. They also changed the crank bolt pattern for the flywheel / flexplate somewhere around 67 or 68, something else to watch out for.
The 425 is a good engine. It will make many a Chebby owner blush.
I'm surprised that nobody mentions the big block oiling problem and the need for restrictors to the upper oil passages. Lots of Olds cranks toasted from lack of oil at high revs.
I feel the short stroke 425 could rev faster, no load, but the 455 torque wins under load!

Jetstar-1

I meant "could be" a 45 degree engine...pre 66.

captjim

"I'm surprised that nobody mentions the big block oiling problem and the need for restrictors to the upper oil passages."

Jetstar 1, Bill Travato has a car that runs high 7s in the 1/4 mile, and he does not use restrictors. So is he right and you wrong?? Not arguing, just reiterating the point that there is more than one way or one opinion.

Jetstar-1

Yup, can just use a bigger oil pan, grind reliefs on the rods to allow lower oil pressure to wash the bearings, lots of stuff you can do.

cutlassefi

Thanks Jim. Norm I believe you said Possibly accurate, as long as it's in neutral or park. IMO that's putting conditions on it and that's your opinion. zand you're right, it was a question, and i answered in theory. it just wasn't what you wanted to hear, plain and simple.

Although it wouldn't be fair to all the 'Norm"'s of the world, but how is it the spelling of your name backwards is just one letter away from the word "Moron'. Hmmmmm. Just like CaptJIm said, if anyone questions you it's a different story. Again, can you prove your statement of "as long as it's in neutral or park? How do you know it is or it isn't. My guess is you probably can't, one way or the other.

Nice job of stealing the thread with a bunch of crap Norm. I'm done here, again.

J-(Chicago)

....

So anyway....
Buy either one, 425 or 455.

Neither of the 2 are 450 HP. (your goal)
So it doesn't really matter.

I'd opt for the 425 crank, but only if there's a matching flexplate, and it isn't junk.

I could draw up some blueprints of garbage can sizes if that will help the seller remember where all the engine info is.

88 coupe

Here it is, again.

If you cannot answer it, just say so.

88 coupe

Here it is, again:

If you cannot answer it, just say so.

Norm

380 Racer

Originally Posted by 88 coupe
........ But if, with all other factors being the same, both were accelerating, how could a 425 "rev faster" than a 455?

It's something called shorter stroke. An example: my SB 425 cube will rev faster than a BB. Pretty simple I would say.

88 coupe

Back on topic:

Could it be, because the "problem" is another myth?

Makes sense to me, but I would rather hear from someone who can present the opposing view, in a mature manner.

Norm

88 coupe

If the same amount of oil is used, the extra depth can control windage, which can free up a few HP. Commonly used on all the other makes, and not unique to Olds.

"Reliefs" were invented by a guy that sold rods for a living. They are a poor substitute for a properly clearanced crank, but many novices have been convinced that they are worth the extra cost.

You want lower pressure in an engine that is already "starved" for oil?

Wouldn't "cool" be a better word than "wash" in this case?

Norm

MN71W30

I think I can scrape up a new signature quote if someone doesn't beat me to it.
This is in the "for in the what it's worth section" The only Olds motors I blew up were 425's. It was for alot of different reasons and I can't prove anything. It was over 25 years back but I do remember several of the pistons cracking and the were Bonolite .040 pistons. The car was a 66 Toro and was a total sleeper. I've had enough cars at the track to know it had low 14's maybe even a high 13 second potential. The power it had after 50 MPH was incredible. I had it going 133 MPH with 4 guys in it and it was still going strong. Either option a 425 or 455 is good in my opinion.

Jetstar-1

Well, the way I learned it was the hard way. The BB Olds has a habit of pumping lots of oil high in the engine and starving the crank and rods at high revs, like during quarter mile runs. Myth? I had a crank that said NO! With a high volume pump or a built standard pump, sustained high revs will pump the oil pan dry. I've seen it. With a larger capacity, less likely to pump dry. Relieving the crank or rod journals will allow more oil flow through the bearings and will let sufficient oil feed the bearings under low or almost no pressure situations. Will also divert oil away from the upper engine because of less resistance to flow. Cool? Yes, oil will cool, but the main purpose is to prevent metal to metal contact in a bearing, so you want as much as you can get to the rod and main journals, or to flow or wash through the bearing with sufficient resistance to keep from "squishing" out. Especially today's low and no zinc oils in older engines. There's an Olds engine builder in Ohio that is seeing pre '65 engines with cam lobe and bearing problems because of the new oils. I can show you an article from Hot Rod magazine on BB Olds builds that the "novice" engine builders recommended reliefs on the rods. I consider myself a novice, only built 3 BB Olds engines. Read a lot, though, before trying it.

88 coupe

Yes, it is a given, that the 425 in question, has a shorter stroke than the 455 in question. Hence my original question

Your engine has nothing to do with this thread.

Not as "simple" as the following:

Explain why your "explanation" is more accurate than this one.

Norm

88 coupe

Let's hear it for anecdotal evidence.

Norm

Jetstar-1

The only engine that will rev faster under the same load is the one with more torque. Why would you care if an engine revved faster without a load?

88 coupe

Higher "revs" than the engine was designed for? Since it did not appear until those limits were exceeded, how can it be called an "oiling problem"?

When the boat guys first started using 455s they had the same issues if they exceeded the design limits of the production engines. They did what I would have done. Take it to a knowledgeable crank grinder, and he/she will tell them that the "problem" is not the oiling system, it is those three inch diameter crank journals that did not have enough clearance for "higher than design" bearing speeds.

Convince me it is not.

You have seen an oil pan, when it was "pumped dry"?

I would like to hear more about this pan when you saw it "pumped dry".

One only needs to tell his/her crank grinder to set the clearances at maximum blueprint tolerances, which he/she will do, as part of the job. Why would anyone want to pay extra for machine work (grooves) that is not needed?

You want low or almost no pressure at high RPM and under full load?

This one will need a little clarification.

And you think that will happen with low or almost no pressure at high RPM and under full load?

Is "squishing out" an engineering term?

Nothing to do with this topic.

I have no doubt that you can.

Many, if not all of those "magazines" have published the same articles, written by the same rod salesman.

I have never "built" any engines.

Norm



Norm

88 coupe

I doubt that 380 Racer appreciates this one as much as I do.

Norm

BIGJERR

So ROP isnt the only forum thats has threads go to crap...........

J-(Chicago)

Nope.

BUT my 2 cents before the big dogs close this thread.
Let's take 2 stock valve covers, and see if the 2 of them will hold 5 quarts of oil.

I'm betting against it.

Although I do think the drainbacks in the heads should have been a little bigger.

I have a pair of 425 covers here with no breathers, that I'll fill up tomorrow.

380 Racer

Norm.....Norm.....Norm, It's too bad you were unable to understand I was only pointing out that my motor has a shorter stroke than a BB and will rev quicker. Sorry I did that and confused you.