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Scofflaw Vicky
Todd Grebin
Southwest Virginia
(7 posts)

Registered:
10/20/2014 09:28AM

Main British Car:
1995 Disco and 1930 Model A 3.9 Rover and 215 Buick respectively

Starting engine build 215 Buick
Posted by: Scofflaw Vicky
Date: October 29, 2014 08:53PM

Hello Group,

Starting engine build soon. I have been looking over other builds, and do not see one exactly like mine. Wondering if I am off track or just came up with something a little different.

Buick 215 block
.040 bore for inexpensive GM 4.4 pistons i found, also .040 1.54 CH 0.927 pin
6.0 chevy rods with press pin for that piston (can only seem to find them in 2.10) so will be using lunati spacer bearings
3.9 Rover 28cc heads and EFI from same engine
.020 under block deck
3.9 crankshaft and front cover

Does anybody see any big wholes in this build?

Will be in very light 5 speed car driven often, and autocrossed occasionally.

Thanks for any advice in advance. Todd


mgb260
Jim Nichols
Sequim,WA
(2463 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Starting engine build 215 Buick
Posted by: mgb260
Date: October 29, 2014 10:00PM

Never thought of the 79-82 267 Chevy V8 pistons. About same pin height as 305 but 3.5 bore. Substantial dish though,only 8.2 compression stock. .020 deck cut give what, 9 to 1, maybe 9.5 with overbore. Steel shim head gasket may give 10-10.5 to 1. Sounds good to me.



Edited 1 time(s). Last edit at 10/29/2014 11:02PM by mgb260.


Moderator
Curtis Jacobson
Portland Oregon
(4577 posts)

Registered:
10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

authors avatar
Re: Starting engine build 215 Buick
Posted by: Moderator
Date: October 29, 2014 11:08PM

Interesting!

Don't 3.9 heads have 37cc chambers? I was thinking the change to 28cc came with 4.0...

After running a 215 for >20 years, I'm thinking a bigger bore size wouldn't be a bad thing.
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mgb260
Jim Nichols
Sequim,WA
(2463 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Starting engine build 215 Buick
Posted by: mgb260
Date: October 29, 2014 11:26PM

Curtis, You are right, I assumed 28cc 4.0 heads. The 3.9 heads will subtract a point of compression. 3.7 sleeves with .036 overbore for 305 pistons routinely done. 305 std size is 3.736.



Edited 1 time(s). Last edit at 11/04/2014 08:26PM by mgb260.


Moderator
Curtis Jacobson
Portland Oregon
(4577 posts)

Registered:
10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

authors avatar
Re: Starting engine build 215 Buick
Posted by: Moderator
Date: October 30, 2014 03:09AM

In either case, check the heads for flatness because they may benefit from being skimmed.

Todd, what compression ratio were you aiming for?


mgb260
Jim Nichols
Sequim,WA
(2463 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Starting engine build 215 Buick
Posted by: mgb260
Date: October 30, 2014 06:55AM

Todd, Also the Chevy rods have to be narrowed .100,.050 per side on the big end, bearings also.


Scofflaw Vicky
Todd Grebin
Southwest Virginia
(7 posts)

Registered:
10/20/2014 09:28AM

Main British Car:
1995 Disco and 1930 Model A 3.9 Rover and 215 Buick respectively

Re: Starting engine build 215 Buick
Posted by: Scofflaw Vicky
Date: October 30, 2014 09:47AM

Yeah I forgot to include the rod milling.

Heads are 1995 10 bolt heads, and I thought all of the ten bolt heads are 28cc?

I am trying to get around 11.0 to 1 just reran the compression calculator 9.64 with composite gasket .050 and 10.52 with .020 steal gasket.

I have dish numbers for the silvolite pistons( -13cc's), but actual pistons are clevite so I will be measuring those when they get here. They look a lot like the buick pistons on top but should be much lighter with slip skirts and higher CH?



MGBV8
Carl Floyd
Kingsport, TN
(4512 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: Starting engine build 215 Buick
Posted by: MGBV8
Date: October 30, 2014 10:10AM

Not sure, there was a transition in 1993-94 that is a bit confusing. 1995 heads would have the smaller combustion chambers, though.

[www.v8forum.co.uk]


Scofflaw Vicky
Todd Grebin
Southwest Virginia
(7 posts)

Registered:
10/20/2014 09:28AM

Main British Car:
1995 Disco and 1930 Model A 3.9 Rover and 215 Buick respectively

Re: Starting engine build 215 Buick
Posted by: Scofflaw Vicky
Date: October 30, 2014 12:12PM

I guess listing head numbers would have helped they are indeed HRC 2479's. Thanks for the link Carl.

Hoping with .040 to .035 quench area, higher compression, aluminum heads, and the 3.9 EFI supplying slightly richer mixture to 220 cid I should be safe enough to run 93 octane fuel with little worry of detonation?

Of course camshaft choices I hear also help with that?


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6470 posts)

Registered:
10/23/2007 12:59PM

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

authors avatar
Re: Starting engine build 215 Buick
Posted by: BlownMGB-V8
Date: October 30, 2014 03:57PM

I'm not sure steel shim head gaskets are a good choice, even if you can still get them. Now if somebody made them in stainless that might work, or in multi-layer stainless. But I don't know of any. Copper is available though and you can specify thickness. But without 0-rings? Maybe.

Jim


Scofflaw Vicky
Todd Grebin
Southwest Virginia
(7 posts)

Registered:
10/20/2014 09:28AM

Main British Car:
1995 Disco and 1930 Model A 3.9 Rover and 215 Buick respectively

Re: Starting engine build 215 Buick
Posted by: Scofflaw Vicky
Date: October 30, 2014 05:55PM

Not sure I like the steelies either, easy to get and cheap, but do not inspire great confidence.

I suppose I could have engine shop deck block .030, and have pistons sit .010 over deck, and maybe have intake ground a bit as well, it seemed tall before compared to the head bolt holes?

Todd
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mgb260
Jim Nichols
Sequim,WA
(2463 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Starting engine build 215 Buick
Posted by: mgb260
Date: November 03, 2014 06:32AM

Todd, For fuel injection you want a minimum of 112LCA and a bit hotter cam than you would think to drop dynamic CR down to run pump gas. Years ago I ran the Crower 50232 in a 215 with the stock 11 to 1 pistons. Would probably work pretty good for you.


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