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tips, technology, tools and techniques related to vehicle driveline components

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BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5284 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Piston Skirt?
Posted by: BlownMGB-V8
Date: May 16, 2017 10:08AM

It might be. You'll know more when you get the pan off. See what identifying marks you can find on the piston once you have it out and we'll try to help identify it and look for a replacement.

Goes without saying, you're excused from the upcoming weekend here. But just to be clear about it. You need to get your ride back together. Whatever we can do to help, we will.

There's some chance I'll have my car off the rack before the weekend. So we'll be swapping that pumpkin in the RM. I'm sure three of us can handle that.

Jim


MGBV8
Carl Floyd
Kingsport, TN
(3181 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Piston Skirt?
Posted by: MGBV8
Date: May 16, 2017 11:02AM

Plan A is out. It is #7 & most all of the full shirt below the wrist pin is gone all the way around. Bee rockin' itself to pieces for awhile.

So, I need one good 1963 Buick 215 JN block 11:1 piston, standard bore . Almost a flattop. Markings say 1353005 Buick on one side & C, then a circle with a 6 in it & BOHNALITE.

Buick 215 broken Skirt.jpg



Edited 1 time(s). Last edit at 05/16/2017 11:20AM by MGBV8.


MGBV8
Carl Floyd
Kingsport, TN
(3181 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Piston Skirt?
Posted by: MGBV8
Date: May 16, 2017 11:08AM

Skirt used to look like this.

215 Piston.jpg


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5284 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Piston Skirt?
Posted by: BlownMGB-V8
Date: May 16, 2017 11:31AM

Looks pretty good actually. Any ring land in the cylinder? Bearing OK?

Have you gathered up all the pieces? You should do that so you can get the total piston weight.

Flat top? Should be able to measure the pin height. Match the pin height and piston weight, slap it back together and run.

It doesn't look like the Silvolite that Summit is selling, but close. They have a slipper style that should work if the weight and CH is close:
[www.summitracing.com]

I wouldn't worry too much about the compression ratio.

Jim


MGBV8
Carl Floyd
Kingsport, TN
(3181 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Piston Skirt?
Posted by: MGBV8
Date: May 16, 2017 11:40AM

May have lost a few smaller pieces years ago doing an oil change. Never saw any, though. It is very, very close to being a flat top. I would think a slipper piston would be much lighter. Dale said if this was a slipper, it would have likely grenaded the engine.

I had this idea that Dan Lagrou might have one way back in the corner of his shop somewhere. I am trying to reach Mark.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5284 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Piston Skirt?
Posted by: BlownMGB-V8
Date: May 16, 2017 02:19PM

There must be other vendors that might have one as well. Phil Baker in Washington comes to mind. Also, Moss could possibly have something. Even TA Performance, they used to be Kenne-Bell. All the old vendors. Probably no Vintage OEM though, it seemed the High Compression Buick 215 supply dried up just about completely in the 80's so you really are looking for something in the corner or take-outs. Which could be a possibility. You're at a stock bore size aren't you? (Better check it.) Mine are long gone so no help there.

Seriously though, I wouldn't get all that hung up on CR. First off, the Buick 4bbl engine was 10-1/4:1 so I'm wondering where you got this 11:1 figure from. Then, the Buick factory CR specs tended to be flexible and optimistic, and the only engine in the series that I know of that really could have been 11:1 was the Olds Turbo motor. (Weird, right?) But it had the same chamber volume as the 4bbl Buick heads. Then what if one cylinder is lower compression? It'll still run just fine. Lose a smidge of power maybe but how long do you plan to run that engine?

Now, let's review CR a bit. All Buick heads have the same chamber volume? So they changed CR with the pistons right? All Olds used the same pistons so they changed CR with the heads? I think that's right. Harry used 2bbl Buick pistons to build a 2bbl Olds and got about 6.5 CR out of it. Still ran. Worked as a spare, but idle wasn't great and mileage sucked. With a turbo mounted on it it was tolerable. Even carbed it beat hell out of an 1800.

So a any Olds piston would also work. How about 3.5 Rover? Do a quick calc of chamber volume and you might find one of those is also close enough.

Jim


MGBV8
Carl Floyd
Kingsport, TN
(3181 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Piston Skirt?
Posted by: MGBV8
Date: May 16, 2017 03:26PM

Mark LaGrou is going to check the back corners of the attic. A local club friend is retired from GM & has sent a request to Detroit friends.

I would prefer a good used piston & reuse the rings/rod bearings as you mentioned & forget any honing.

As for CR, the 10.25:1 you quote is for the 185HP 4bbl in 1961 & 1962. In 1963, they bumped the CR to 11:1 & rated it at 200HP.

[www.carnut.com]



roverman
Art Gertz
Winchester, CA.
(2860 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Piston Skirt?
Posted by: roverman
Date: May 16, 2017 07:50PM

Carl, give us a skirt diameter and where measured, in relation to pin location. I'll look as soon as I can. Good Luck, Art.


roverman
Art Gertz
Winchester, CA.
(2860 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Piston Skirt?
Posted by: roverman
Date: May 16, 2017 07:58PM

I would be very cautious about using flat top Olds pistons, with Buick heads. Valves are in different location !


mstemp
Mike Stemp
Calgary, Canada
(176 posts)

Registered:
11/25/2009 07:18AM

Main British Car:
1980 MGB Rover 4.6L

Re: Piston Skirt?
Posted by: mstemp
Date: May 16, 2017 09:46PM

Carl,

What I still can't believe is that the large piece made it up to the lifter valley! You would think it would have jamed itself in the bottom end. And how did it not wipe out the cam getting up there, or lock up a push rod???

Engine gods were smiling up on you!


rficalora
Rob Ficalora
Cypress, TX
(2336 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

authors avatar
Re: Piston Skirt?
Posted by: rficalora
Date: May 16, 2017 10:48PM

Carl, just an idea... I dont know much about the BOPR series of motors. If you can't find a piston, is there a BOPR you could pick up used that'll work with your headers, bell housing and accessories? If so, maybe you could swap out the motor or short block at least. Then simply resell it after the meet. I've don that with expensive tools. Sometimes even made money when reselling.


Mickey Richaud
Mickey Richaud
Townsend TN
(96 posts)

Registered:
08/25/2015 06:36AM

Main British Car:
'69 BGT GM 3.4

Re: Piston Skirt?
Posted by: Mickey Richaud
Date: May 17, 2017 06:55AM

Tony Gentile just posted an engine for sale - maybe something here?

[www.racingjunk.com]


Scott68B
Scott Costanzo
Columbus, Ohio
(489 posts)

Registered:
10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: Piston Skirt?
Posted by: Scott68B
Date: May 17, 2017 08:22AM

Carl,

Glad you decided to investigate further. It would have sucked to have that piston let go during the meet. You still have 3 weeks (from today!) to get something in place.

Scott


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5284 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Piston Skirt?
Posted by: BlownMGB-V8
Date: May 17, 2017 09:14AM

Hope you're looking at the motor Tony posted:
[www.racingjunk.com]

Sounds about like the motor you bought when you did your conversion originally. Oklahoma, $500.

Jim


MGBV8
Carl Floyd
Kingsport, TN
(3181 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Piston Skirt?
Posted by: MGBV8
Date: May 17, 2017 10:36AM

The engine I bought 16+ years ago for $600 was already rebuilt. :) I have options (besides R&R and rebuilding an engine in 3 weeks). Too short on time. I drove my dad's original owner '63 B to the MG V8 Meet in Westlake, Ohio in 2000. It may be coming to WV. :)

Dale Spooner said he has seen a piece o' skirt in the lifter valley once before. The cam looks good. I was surprised.



Edited 2 time(s). Last edit at 05/17/2017 11:57AM by MGBV8.



MGBV8
Carl Floyd
Kingsport, TN
(3181 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Piston Skirt?
Posted by: MGBV8
Date: May 17, 2017 11:53AM

I agree with caution on the Olds flat top piston, Art. I do believe it would work with my "stock" cam. My 11:1 piston only has a .010" dish & is .060" below the deck. The head gasket was a compressed .050". IF the Olds has the same compression height, I'd try it.

My piston measures 3.502 on the wrist pin centerline. There is not much skirt left.


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(5284 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: Piston Skirt?
Posted by: BlownMGB-V8
Date: May 17, 2017 12:15PM

That engine above isn't rebuilt?


MGBV8
Carl Floyd
Kingsport, TN
(3181 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: Piston Skirt?
Posted by: MGBV8
Date: May 17, 2017 12:22PM

Not the way I read it. Also, local pickup only in Oklahoma

" engine was dismantled for rebuild but my project list has changed..."


DiDueColpi
Fred Key
West coast - Canada
(1210 posts)

Registered:
05/14/2010 03:06AM

Main British Car:
What if the Hokey Pokey really is what it's all about?

authors avatar
Re: Piston Skirt?
Posted by: DiDueColpi
Date: May 17, 2017 01:01PM

There's a few sets of used piston and rod sets on Ebay right now.


Dan B
Dan Blackwood
South Charleston, WV
(890 posts)

Registered:
11/06/2007 01:55PM

Main British Car:
1966 TR4A, 1980 TR7 Multiport EFI MegaSquirt on the TR4A. Lexus V8 pl

authors avatar
Re: Piston Skirt?
Posted by: Dan B
Date: May 17, 2017 04:25PM

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