OliverFHH

Hi there, thanks for all your help on my engine knocking diagnosis! After weeks of discussion I finally decides to get a replacement motor for my 76 Ninety-Eight Regency to save rebuilding cost (very expensive here in NZ, could be up to $7-9k, no one here is willing to open the valve cover, unfortunately).

Few questions here:

1, I've been suggested that any 64-90 Oldsmobile engines ranges from 260 to 455 will fit my car without any modification required, since their sizes and shapes are identical, and I should consider install a Olds 350 since it works OK on the Delta 88 of the same year, if I cannot find or afford another 455. One mate says that he has a near three-ton Safari truck that has the 4.2L engine (but a diesel one) that works alright. Will an Olds 350 have sufficient horsepower to drag my 2.2 ton landyacht, given that I'm just driving it on New Zealand roads with the maximum allowable speed of 65mph? Will a smaller engine affect the mpg/fuel economy (either improving or worsen)?

2, a classic car restoration company here is shipping containers regularly from the States, and the port is at the Memphis Area. The shipping cost with them would only be around NZD$500. Does anyone here from the area, or know anyone in that region who has a rebuilt Olds engine (no matter 350, 400, 403 or 455) that is priced around $1-2k, best with the warranty?

(I just found number of very cheap ones in Memphis:
http://memphis.craigslist.org/pts/5141080470.html
https://memphis.craigslist.org/ptd/5079601234.html (parting out)
looks alright, but can I trust them?)

Would be greatly appreciated if anyone can help on that cheers!

MDchanic

My '73 Delta is essentially the same car, and had a 260 in it when I got it.

It "progressed at a stately pace," as one says of the Daimler, but I was able to drive it on the highway without drama.

My fuel mileage actually improved when I installed a 10.25:1 1968 350.

- Eric

jaunty75

Keep in mind that the 98 was never offered with anything other than Oldsmobile's largest, most powerful engine at the time. While this was certainly partly due to the fact that the 98 was the flagship model for Oldsmobile, it was certainly also due to the fact that the 98 was always the largest, heaviest car Olds offered in any given year.

For the '71 to '76 era, the 98s were larger and heavier than at any other time in Olds history. While the Delta 88 could have been had with a 350 or a 455, the 98 came only with the 455. Depending on body style, the '76 98 was always about 200 to 300 lbs heavier than the same-year Delta 88, and the '75 and '76 98s were the heaviest ever offered.

If it were me, I would look for another 455. It's what's meant for the car and will give the best driving experience. A 350 would certainly work, but the car would likely feel underpowered and might at times feel like it can't get out of its own way. A 260 would be a joke. If you're going to do that, you might as well put in a rubber-band motor or a squirrel cage!

MDchanic

Remember, he lives in a country with a low speed limit and a high gasoline price (it looks like he pays US$5.46 a gallon), so a 455, while correct for the car, may not be correct for him.

I'd certainly look for the 455, and is a member here has a viable one near Memphis, he may be able to find one at a reasonable price, but their cost looks prohibitive over there.

Of course, we still don't know what's wrong with his original motor...

- Eric

jaunty75

Is he driving this car as a daily driver or as a collector car? I'm assuming as a collector car, which means he doesn't drive it that much, so how much he pays for gas is probably less important than the quality and enjoyment of driving the vehicle.

If his desire is to go slow and save money on gas, he should get a smaller car, not put a too-small engine in a large car.

joe_padavano

I'm sorry, but the whole premise of this thread is flawed. It must be nice for your mechanic to be so busy that they can turn away work and not even take the time to pull ten bolts on the valve cover.

It will almost CERTAINLY be less expensive to rebuild the engine that's in the car now. It is certainly possible to change to a different Olds motor, as the Ninety Eight chassis is identical to the Eighty Eight chassis from the firewall forward. Just understand that while a small block Olds bolts to the current frame mounts, there WILL be some collateral damage (new exhaust manifolds and pipe routing, due to the lower deck height, for example). Changing to an Olds 350 diesel is also possible, but requires CONSIDERABLY more work, including fuel system and glow plug wiring mods.

Find a shop who has a clue and needs the work.

MDchanic

No argument here.

But I'm not privy to his inner thoughts and desires.

- Eric

MDchanic

If you think the premise of this one is flawed, you should see the other one.

- Eric

OliverFHH

Hi thanks everyone. I have a tendency of making it my dailydriver, and my original motor was actually not bad on gas. My main concern over a smaller engine here is, however, that will an Olds 350 makes the mileage/fuel economy even worse? And what about an Olds 400, 403 etc.? Of course, an original 455 is always my first preference if a rebuilt one is not too expensive!

OliverFHH

With the mechanics we have here, I think it will CERTAINLY cost $5-9k to rebuild the existing motor, it may not worth that to fix the problem but it is out of their freewill. I cannot argue with them, unfortunately. Would be much better if I know how to do everything myself.

I knew the 350 has the lower deck height, but never know that it will cause damage. If so that means more money will be sucked into rebuilding other parts (or again some modification works will be required prior installation). Do you know how would an Olds 400 or 403 fit and work?

jaunty75

You probably will get better mileage with a 350 instead of a 455, but probably not enough to mention, and you may sacrifice driveability. These big Oldsmobiles were never known for their fuel mileage. As I said earlier, if daily driver use is what you want, and fuel economy is an issue, you shouldn't be driving a car like this in the first place.

I don't understand this question. Wouldn't a 400 or 403 have to be rebuilt, too? Why does the 455 have to be rebuilt? Are you talking about having one rebuilt after you find it, or are you looking for one that's already rebuilt? If the latter, the question is really much simpler. You're just looking for an engine that's in good shape and ready to drop into your car whether it's a 200,000 mile motor that needs rebuilding or a low-mileage one that doesn't.

The other thing I don't quite understand is why you think a 455, rebuilt or otherwise, would be "too expensive" but you don't seem to show this concern for any other engine. Isn't it the case that it doesn't really matter what engine you get because the main expense is going to be shipping it to New Zealand?


I think Joe Padavano is right. You have the engine you need right in front of you. You know its history (more or less), you know its condition, you know what's wrong. It's hard to believe buying some totally unknown motor from the other side of the world that you'll likely only know about through pictures and descriptions is better than getting your own motor fixed. It's difficult to believe that, in a modern country like New Zealand, you can't find someone to fix it.

OliverFHH

Not just what I think, but the $5-9k rebuilding rate was given by the mechanics here, so there is no way I can do it cheap since it is not me who is doing the labour.

I saw some rebuilt engines for sale in States, an Olds 350 for $1100 and a 400/455 for $1800-1900, and the 400 I saw was built for a 75 Ninety-Eight. Will find the links and post here. I think I can basically rule out the 350 option consider the potential damage.

Professur

My Custom Cruiser sells with a similar curb weight and manages to embarrass plenty of Civics with a mere 307. But concerning your existing engine ... leave your corner garage mechanic and find yourself a speed shop that isn't afraid of a 50 year old engine.

OliverFHH

Here is the rebuilt Olds 400 engine I saw that is selling for $1,800 and indicated as fitting the 75 Ninety-Eight: http://www.rebuiltautoengines.com/ol..._2-engine.html any comment?

joe_padavano

When I said "collateral damage", I was jokingly referring to other stuff that has to change, not physical damage.

As a refresher, Olds had two second-gen engine families, small block and big block. The SBO family includes the 260, 307, 330, 350, 403, and diesel motors. These are all externally identical. The BBO family includes the short stroke 400, long stroke 400, 425, and 455. Again, these are externally identical. The only physical difference between the BBO and SBO families as far as swapping is the deck height. The taller deck on the BBOs means that the exhaust ports are higher above the crank centerline, which changes exhaust routing. In some cases the accessory brackets are different, but this typically applies to years where the BBO was not offered (such as 1977-1990). In the late 60s/early70s the accessory brackets were typically designed to fit both deck heights, usually through the use of two sets of mounting holes where needed.

MDchanic

That's a Pontiac engine.

It won't bolt up directly without different motor mounts and exhaust pipes (correct, Joe?), so you're just opening up a can of worms.

- Eric

OliverFHH

How do you find out that is a Pontiac engine? (from Part Number:PON-400LB-2???)

Why they labeled it to Oldsmobiles?

jaunty75

In 1975, Oldsmobile offered a 400 along with a 350 and a 455. It was a Pontiac motor, and 1975 was the only year of that era of big Oldsmobiles ('71 to '76) that Olds offered this engine.


See the attached image, which is out of the '75 Olds chassis service manual, and note the second and third columns from the right.

MDchanic

As Jaunty said, a '75-only, fullsize-only 400 MUST be a Pontiac motor.

Also, the number, PON-400LB, confirms it.

PON: Pontiac
400: 400cid
LB: Long Block.

- Eric

OliverFHH

Ah that's an interesting history to know! So if this 400 engine fits the 75 Ninety-Eight, can we assume that it will fit the 76 too? Or were those 75 Ninety-Eight that were offered the 400 option been modified to fit the Pontiac engine?

oldcutlass

I think they are trying to tell you the application in that website is wrong.

Rocketowner

Here's the authorized dealer For JASPER ENGINES in Memphis Tennessee.G&H Auto Service, 1645 Rockdale Ave. Memphis, Tn. 38116. phone# 901-332-4104. Jasper is a old ,reliable builder of all sizes and types of engines,and having locations in Memphis, should be simple to arrange shipping.They have a 3yr. Or 100,000 mile warranty. Good luck, Larry

jaunty75

How so? I think that website is exactly right. It shows the 400 as applicable to 1975 Delta 88, 98, and Custom Cruiser, which is what the chart from the chassis service manual shows.

I know that listing the application as "1975-1975" instead of simply "1975" is a little funny-looking, but it's obvious what is meant.


Applications: 1975 - 1975 Oldsmobile 98
1975 - 1975 Oldsmobile Custom Cruiser
1975 - 1975 Oldsmobile 98
1975 - 1975 Oldsmobile Delta 88
1975 - 1975 Oldsmobile Delta 88

joe_padavano

It's incorrect because the Poncho 400 was only available in the 1975 D88, NOT the Ninety Eight. I'm pretty sure it was not available in the Custom Cruiser either.

jaunty75

I always thought so, too, but then how do you square this with the chart from the '75 CSM, which clearly shows a 400 as an application in the 98 and Custom Cruiser? Was this CSM an early print and made before final decisions were made as to what engines would be offered?

joe_padavano

Well, turns out you (and the CSM) are correct. Sorry for the mis-information. Even the 1975 dealer brochure shows the 400 as available in the Ninety Eight line.

Learn something new every day.

jaunty75

Well, I can't speak for the CSM, but as far as me, I'm not surprised. I'm always correct.

Ancient Iron

[QUOTE=OliverFHH;848165]Hi there, thanks for all your help on my engine knocking diagnosis! After weeks of discussion I finally decides to get a replacement motor for my 76 Ninety-Eight Regency to save rebuilding cost (very expensive here in NZ, could be up to $7-9k, no one here is willing to open the valve cover, unfortunately).

Few questions here:

1, I've been suggested that any 64-90 Oldsmobile engines ranges from 260 to 455 will fit my car without any modification required,


The only engine from '64 that would bolt in would be a 330. the newer style big block (400,425,455 started in 1965.) I would look at either fixing the original 455 or find another 455.
A 350 will work, as for gas mileage it might burn a little bit more fuel due to less torque.

joe_padavano

Yes, but hopefully most people here understand that when we say 1964-1990, we mean the second gen Olds V8. It's easier than adding "except the 1964 394" every time this gets written.

oldcutlass

Did not know a Pontiac 400 came in an Olds in 75, guess you learn something everyday.

OliverFHH

Hey mate would be interested to know that which year is your Custom Cruiser and what's the mpg?

Cheers,
Oliver

OliverFHH

Thank you for the information! Do you have a clue about their price range?

Cheers!

jaunty75

They're not really that close in weight. You don't state the year of your CC, but the first year for the 307 was 1980. A 1980 Custom Cruiser has a curb weight of 4081 lbs, and all the CC's of that era were in the 4000 to 4200 lb range with most years less than 4100. The weight of a '76 98, by contrast, is in the 4700 to 4800 lb range, depending on body style. That's an almost 20% greater weight.

joe_padavano

Most of the 1980s Custom Cruisers also came with a 200-4R trans, with 0.68:1 overdrive.

OliverFHH

May well be that similar to MDchanic's '73 Delta 88 which had a 260 when he got it? We have to know the year first. Any post-77 GM were significantly downsized and incomparable with those made up to 76.

76 Regency

Hey Oliver, any updates on your 98 ?