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What all v-6 engines will replace this one?

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260mgb Jim Nichols
Sequim,WA, USA   USA
I just put in 3.2 to see if the 3.8 interchanges,

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Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
Jim, that Partsgeek flywheel fits a SBC, not the Buick engines. I bought one and had to send it back.

Look at your flywheel and see if it has a relatively large pocket in the back side. If it does it is an externally balanced engine. If not then it isn't. Look at the flexplate off the new engine. Same thing, if it has a large cutout on one side it is externally balanced. You can also tell by looking at the harmonic damper.

This is a BOP bellhousing:
https://encrypted-tbn3.gstatic.com/shopping?q=tbn:ANd9GcSREzo3bZkQoWTWvG-3zXn1La84gUZyLrtdZJowfBqahntOXbD549nXtnyisw&usqp=CAc



This is a small GM corp bellhousing:
https://en.wikipedia.org/wiki/File:GM_60deg_V6_bellhousing.JPG



You can easily tell them apart by visual inspection. Your engine uses the BOP pattern.

Jim

twentyover Avatar
twentyover Greg Fast
Lives in SoCal, Resides in the Burbs of Detroit MI, USA   USA
In reply to # 3742707 by chris I wonder why they don't show the rest of the years that this OE engine is listed for, 79-84.

No OEM RWD manual transmissions offered in cars those years? I know that 1981 was he last year MT was offered in G body, probably the last home for RWD 3.8's and that was only 305's in California

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chris Avatar
chris Platinum Member Chris Roop
Pendleton, OR, USA   USA
There will be no flex plate or flywheel that comes with this new engine. It is a factory build, not a reman. No oil pan, intake, etc.


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Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
Does it come with a crankshaft damper? Can the seller show you the one that matches it if not? Or the flexplate that matches it?

Look at the weights on the damper. Same scenario. If it looks unbalanced it's for an externally balanced engine.

chris Avatar
chris Platinum Member Chris Roop
Pendleton, OR, USA   USA
Today's question! Rick found a 1985/6 Buick Regal with vin #1G3GR47A0GRxxxxxx. It has an odd fire distributor, the top two bell housing bolt holes are 7" apart, and it is thought to be a 3.8. It doesn't have a casting number on top of that rear lip like the 3.2 did. The balancer seems to be the same (we are comparing notes from 30 miles away from each other). Does this sound like the engine I've been looking for??



Edited 1 time(s). Last edit at 2018-05-27 08:39 AM by chris.


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260mgb Jim Nichols
Sequim,WA, USA   USA
Chris, He can't have an oddfire distributor on an even fire motor. If it ran at all it would not run very good. Last oddfire motor was mid 77 231. 231 was 75-77. The older 61-63 198 oddfire and 64-67 225 odd fire. The 225,231,3.8 and 4.1 use the same BOP bellhousing. the 61-63 198 uses the same bellhousing as the 215 V8. It may be an older motor someone put in the Regal? Not a good idea to mix oddfire and evenfire parts. They may all use the same dampers and flywheels, I don't now. I've always stayed 225/231 oddfire and 3.8/4.1 evenfire and not had any issues. Never seen a 3.2 but should be the same as 3.8 with smaller bore. The 3.0 is shorter and narrower due to lower deck and shorter stroke, so avoid that one too.



Edited 1 time(s). Last edit at 2018-05-26 03:43 PM by 260mgb.

chris Avatar
chris Platinum Member Chris Roop
Pendleton, OR, USA   USA
This is such a mystery! The engine I'm trying to replace is an odd fire and the casting number of 1261785 lists it as a 78-79. What to do.
Edit: I just ran the vin through a decoder and it comes up as an Olds with a Buick engine, 1986, and is supposed to have mpfi, yet, the engine has a 2 bbl sitting on top which makes me wonder if the engine was pulled from an older car and dropped in to replace a blown one.



Edited 1 time(s). Last edit at 2018-05-26 04:03 PM by chris.


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260mgb Jim Nichols
Sequim,WA, USA   USA
Chris, The oddfire block never had the high port heads either. Are you going from the distributor cap or if the pan is pulled the connecting rods are on a shared journal for the oddfire where the even fire is split. It maybe an even fire with oddfire cap. That may still run OK. There are little bars in the cap to time with the oddfire. I know the odd fire backfires and barely runs with the evenfire cap. Don't ask me how I know! The odd fire fires at 90-150-90-150-90-150. Evenfire 120-120-120-120-120-120. We'll figure it out.

260mgb Jim Nichols
Sequim,WA, USA   USA
Just to confuse things further this site shows that block # as 78-87 3.8 V6 which would be evenfire also:
You would have to pull a head to verify 3.5 bore for 3.2 or 3.8 bore for 3.8.

https://www.teambuick.com/reference/casting_numbers_231-252.php



Edited 1 time(s). Last edit at 2018-05-26 04:11 PM by 260mgb.

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Salmon Arm, BC, Canada   CAN
1977 MG MGB
I've just sent an email to the previous owner, the fellow who rebuilt the car with his son.

Hopefully he'll read this thread and chime in with needed information.

chris Avatar
chris Platinum Member Chris Roop
Pendleton, OR, USA   USA
This is what I got from Team Buick: 1261785 78-87 ***, 2BC, 4BC, SFI, Turbo
Are the 3 asterisks supposed to be 3.8?? I'm interpreting 2 and 4 barrel, something fuel injection, and the turbo.
The engine in the car with the casting number above has high port heads and an odd fire distributor cap. I didn't pull it to look inside.


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Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
If you pull a head it is easy to confirm even or odd fire, but why do you care? I mean, seriously the evenfire is going to be more practical as a replacement and any engine you get you can pull the pan and look at the crank throws. Here is an even fire crank:



https://www.google.com/url?sa=i&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwiwoOO0tqTbAhVOslMKHeqiCrMQjRx6BAgBEAU&url=https%3A%2F%2Fwww.jalopyjournal.com%2Fforum%2Fthreads%2Feven-fire-vs-odd-fire.286188%2F&psig=AOvVaw1B6Y6JphpqVcr5stAPAEgF&ust=1527460075163637

Jim

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Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd, Florence, KY, USA   USA
OK that didn't work.


260mgb Jim Nichols
Sequim,WA, USA   USA
Oddfire crank picture:


Attachments:
odd fire crank.jpg    72.6 KB
odd fire crank.jpg

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