gm bowtie sportsman block
10-07-2008, 06:11 AM
#1
Cruising
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gm bowtie sportsman block
any one here have or used a gm # 12480174 bowtie sportsman block with good results with a new modded full rebuild ?
they are a single rear main seal block and have siamese bores that can be bored succesfully and safely out to 4.155 " if needed.
there quite expensive though by the look but iv got a new 3.75" forged lite weight s/crank and canton 7 qrt race pan also both to suit 1 prms.
iv got some probe forged lite weight flat top pistons .60" over size to take it out to a 388 c.i.
tia
they are a single rear main seal block and have siamese bores that can be bored succesfully and safely out to 4.155 " if needed.
there quite expensive though by the look but iv got a new 3.75" forged lite weight s/crank and canton 7 qrt race pan also both to suit 1 prms.
iv got some probe forged lite weight flat top pistons .60" over size to take it out to a 388 c.i.
tia
Last edited by 8 t/b vet; 10-07-2008 at 06:21 AM.
10-07-2008, 06:49 AM
#2
Melting Slicks
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I ran some 400 blocks with siamese bores & had to drill the heads for steam holes.
They are about 40# heavier than a standard 350 4 bolt block.
I have a fresh 400 block ready to go if your interested. Bored .030, decked to 9" & line bored. Its a 2 piece rear main seal block. Use main bearing spacers or bearings designed for a 350 journal size arm in a 400 block if you want to go that route. Its 377 cu in with a 350 (3.48 stroke) crank. Will include a new set of flat top pistons for a 350 stroke crank.
406 cu in with 3.75 arm.
700.00 OTD.
They are about 40# heavier than a standard 350 4 bolt block.
I have a fresh 400 block ready to go if your interested. Bored .030, decked to 9" & line bored. Its a 2 piece rear main seal block. Use main bearing spacers or bearings designed for a 350 journal size arm in a 400 block if you want to go that route. Its 377 cu in with a 350 (3.48 stroke) crank. Will include a new set of flat top pistons for a 350 stroke crank.
406 cu in with 3.75 arm.
700.00 OTD.
Last edited by Churchkey; 10-07-2008 at 07:00 AM.
10-07-2008, 09:05 AM
#3
I am using one, and my engine builder who is on this forum has used them many times. They are known to support over 1000hp.
My motor isnt done yet, but I certainly have no concerns with that block. It's pretty kick azz!
My motor isnt done yet, but I certainly have no concerns with that block. It's pretty kick azz!
10-07-2008, 05:00 PM
#6
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St. Jude Donor '05
mseven just built one, came out pretty nice.
10-08-2008, 02:38 AM
#8
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St. Jude Donor '05
10-08-2008, 08:52 AM
#9
This is from John Lingenfelter's book:
"The major Bow Tie block improvements over stock involve the use of high nickel content cast-iron, thicker cylinder walls and deck surfaces as well as a number of other changes that make the difference between compromising with a production block and using the casting that championship drag racers and NASCAR stock cars win with every weekend. How strong are these Bow Tie blocks? I've been able to coax over 1400 hp from a Bow Tie block with no durability problems."
"The major Bow Tie block improvements over stock involve the use of high nickel content cast-iron, thicker cylinder walls and deck surfaces as well as a number of other changes that make the difference between compromising with a production block and using the casting that championship drag racers and NASCAR stock cars win with every weekend. How strong are these Bow Tie blocks? I've been able to coax over 1400 hp from a Bow Tie block with no durability problems."
10-08-2008, 12:03 PM
#10
Drifting
any one here have or used a gm # 12480174 bowtie sportsman block with good results with a new modded full rebuild ?
they are a single rear main seal block and have siamese bores that can be bored succesfully and safely out to 4.155 " if needed.
there quite expensive though by the look but iv got a new 3.75" forged lite weight s/crank and canton 7 qrt race pan also both to suit 1 prms.
iv got some probe forged lite weight flat top pistons .60" over size to take it out to a 388 c.i.
tia
they are a single rear main seal block and have siamese bores that can be bored succesfully and safely out to 4.155 " if needed.
there quite expensive though by the look but iv got a new 3.75" forged lite weight s/crank and canton 7 qrt race pan also both to suit 1 prms.
iv got some probe forged lite weight flat top pistons .60" over size to take it out to a 388 c.i.
tia
10-09-2008, 09:07 AM
#12
Le Mans Master
It's definetely a good block and I am a fan of a 1 peice rear main. I think msot of it depends on what you ci. you are building and your budget, as there are some other good choices out there.
