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Use 1976 head on 1967 block?

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brushby Fred B
Arlington, WA, USA   USA
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I recently purchase a 1967 mgb. It turns out that is has a crack in the head. I happen to have a head from a 1976 MGB laying around. Is it possible to use the 76 head on the 67 block?

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Cubfloater Gold Member Jim Tice
Monroe, NC, USA   USA
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1973 MG MGB
1974 MG MGB
In reply to # 2953430 by brushby I recently purchase a 1967 mgb. It turns out that is has a crack in the head. I happen to have a head from a 1976 MGB laying around. Is it possible to use the 76 head on the 67 block?

I'll be interested in the responses and have a similar dilemma. I have a reworked head (74) that I would like to put on a 70 engine maybe. Or maybe not. The 74 block needs to be rebuilt and crank replaced. The 70 seems to be running okay. Just got it running after maybe 15 years of sitting. What am I up against on mine as well? Thanks for chiming in.

Jim

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ohlord Avatar
ohlord Platinum Member Rob C
A tiny Island off the coast of Washington State, N.W., USA   USA
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1957 Land Rover Series I "EYEYIYI"
1957 Land Rover Series I "OVRLND"
1971 MG MGB
1971 MG MGB "Bedouin 2"    & more
It is an offset small chamber 39CC the block would need cut outs on the exhaust valve side and the head would yield a street gas unfriendly compression ratio over 10:1. Locate a non 18V head. much less work and run regular fuel.



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Edited 1 time(s). Last edit at 2015-03-31 07:28 PM by ohlord.

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DB Wood Avatar
DB Wood Daniel Wood
Tumalo, OR, USA   USA
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1967 MG MGB GT
1968 MG MGB
1970 MG MGB GT
Yes you can use it on a 67 block and with the shallow dish (HC) pistons will give you a compression ratio of about 9.4 to 1. Have it checked for cracks before making any plans to use it though. All of the emissions heads are prone to cracking. Also, I have read that the CAM1106 head has fewer coolant holes to the block, but can be drilled out for better cooling. Maybe someone more knowledgeable can fill in the blanks about that..



Dan Wood
70BGT driver, OD, Pertronix, HS4's, Peco, .060 over, Elgin cam, Superlite wheels, poly bushings, panhard rod, rear tube shocks, 1" lowered front end, HD shock valves, etc, etc.
68 MGB rebuilt engine D9 cam balanced, still a work in process but runs real nice.
88 Saab SPG Turbo
86 Vanagon Westy (South African conversion engine 2.0 OHC 135HP) This car burnt to the ground. Bought another, same year and color but with a 2.4 Waterboxer.
2004 Dodge Ram 6sp with HO Cummins diesel
Lucas= Loose
Unsoldered
Connections
And
Splices

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JuancarlosMGB Avatar
JuancarlosMGB Juan Perez
San Salvador, San Salvador, El Salvador   SLV
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1974 MG MGB GT "El Cherada"
1978 MG MGB Racecar "El 81 De Carrera"
1995 Honda Civic "Beasty Boy (Race Car)"
1999 BMW Z3 Coupe "BATMOBILE"
Fred & Jim: Using a later 18V head (from 1972 and on) in an earlier engine (18G) will increase the Compression ratio to values about 9.4:1. That could put too much stress on worn parts like main & rod bearings, piston rings or, even in the cylinder head itself. But if you are ready for a total rebuild, you will have a very nice engine with a very decent power. If you want to keep your block as it is, it's better to get an earlier head.

In this article you can find more information about head configurations:

http://www.mgbmga.com/tech/mgb25.htm

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Cubfloater Gold Member Jim Tice
Monroe, NC, USA   USA
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1973 MG MGB
1974 MG MGB
Thanks, if I need to do anything head wise I'll just rework the one on the 70 sounds like the best option in my case. I'm assuming it hasn't been rebuilt and there is 9,000 miles showing on the odometer so I'm guessing just turned over in 92. It's in a parts car and I want to see if it seems okay to use. Maybe I can find a good GT that needs a motor somewhere.

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brushby Fred B
Arlington, WA, USA   USA
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Thank you for the responses on this. I attached a picture of the heads side by side. The 1967 head is the cleaner one with no valves in it. There are definitely differences in the number of coolant holes in the two heads. I am not going to try to swap the heads due to this and the compression ratio issues. I was told by machine shops that they could repair the 1967 head and put in hardened seats for the exhaust valves for $400-$500.


Attachments:
20150331_181645.jpg    56 KB
20150331_181645.jpg

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trialsrider Avatar
trialsrider Silver Member Richard Bussler
South Williamsport, PA, USA   USA
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I did exactly what you are talking about,1980 head on a 67 block,cut the eyebrows in with a die grinder and one and one half disc.the block is 20 overbore,its runs very well on pump gas.

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brushby Fred B
Arlington, WA, USA   USA
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Do you have any pics of the cutting of the eyebrows? What about the different number of coolant passages? Did that cause any problems?

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JuancarlosMGB Avatar
JuancarlosMGB Juan Perez
San Salvador, San Salvador, El Salvador   SLV
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1974 MG MGB GT "El Cherada"
1978 MG MGB Racecar "El 81 De Carrera"
1995 Honda Civic "Beasty Boy (Race Car)"
1999 BMW Z3 Coupe "BATMOBILE"
Fred: here you have a link with some information about the eyebrows. Regarding the wáter passages; I'm pretty sure somebody elese will answer your question.

http://mgaguru.com/mgtech/power/cm202a.htm

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trialsrider Silver Member Richard Bussler
South Williamsport, PA, USA   USA
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As far as the cooling last summer the water temp never got above 180 even aftre 1 mile at 5000 rpm

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brushby Fred B
Arlington, WA, USA   USA
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I would assume that you would have to use the pushrods from the newer head. Do the lifters need to be taken from the block that the newer head came from as well?

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ohlord Avatar
ohlord Platinum Member Rob C
A tiny Island off the coast of Washington State, N.W., USA   USA
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1957 Land Rover Series I "EYEYIYI"
1957 Land Rover Series I "OVRLND"
1971 MG MGB
1971 MG MGB "Bedouin 2"    & more
The 18v head has offset oil feed the complete rocker assembly from your 67 would need to be swapped. If the 18v has the rear water port for a zs water choke that also needs to be blocked off.
Don't pay for welding a head that is only for heads so high priced it is worth saving them.
Find an early head and have it rebuilt dual springs etc like its supposed to have.
PM me we are in the same area and excellent head rebuilder is not far from you.
Rob
I just posted a how to DIY exhaust cut outs on a 18v head but it will be more thn the 9.4 compression some claim and you will be limited to high test fuel and non optimal advance timing.



LNDRVR4X4.COM
Home of Project "INCARN8'


1957 Series 1 Land Rover electric VEHICLE CONVERSION

FIXITUPCHAP.COM
FIXITUPCHAP INCORPORATED

RD3 Radar/ Electronic Warfare Technician
VIETNAM 1969-1972



Edited 1 time(s). Last edit at 2015-04-01 07:34 PM by ohlord.

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JuancarlosMGB Avatar
JuancarlosMGB Juan Perez
San Salvador, San Salvador, El Salvador   SLV
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1974 MG MGB GT "El Cherada"
1978 MG MGB Racecar "El 81 De Carrera"
1995 Honda Civic "Beasty Boy (Race Car)"
1999 BMW Z3 Coupe "BATMOBILE"
Fred: as you can see there are a lot of important tasks involved if you want to use the later head in an earlier block.
Sometimes using some engine part only because "you already have it" it's not necesary the best decission. Trust me, I am dealing with a similar decission right now.
I showed you some information because you requested it; but you'd better get an early head and everything will be easier. And above all, get in contact with Rob.

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trialsrider Silver Member Richard Bussler
South Williamsport, PA, USA   USA
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Guess i better not 87 octain in mine like i did all lasr summer

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