The Ford Barn

my4dv8 · 03-28-2019, 03:21 AM

We are still on a steep learning curve to 4 bangers ,( know our way around V8s well)
We want to build a B4 into a decent runner to give the banger knockers a fright,and give us a big smile.
We already have a nice Cragar OHV set up, but are interested in folks thoughts on the full rotating assembly . We know we will be full pressure oil etc. Jim Brierlys book touches on it for OHV but doesnt give detailed info. We want to run 60 mph all day with 3.5 rear gears and 750x16 tyres. We know we will have the odd hurried sprint but no extended high speed time just spirited street driving, maybe ,unless we weaken to more short outbursts for fun.
We think higher compression pistons may help ,aiming at 8 to 1. But dont know how to get there.
Is a new scat crank and some new rods necessary.
We have a Brierlys cam for what he recommended for our planned combo. Need to check numbers on that.
We have Twin 81 strombergs and headers along with an
FS ignition.
But thats as far as we know.
We just want a solid reliable hard runner.

Jim Brierley · 03-28-2019, 01:01 PM

Scat cranks are nice but not needed for what you are doing, a "C" crank will be more than adequate. Full oil pressure isn't mandatory either, stock oiling is good to at least 4,000 RPM. If your Cragar is an old iron one, the combustion chamber has no shape, so doesn't promote any swirl of the fuel mixture, resulting in LOTS of spark advance needed. 8:1 would be good, I'd do it with pistons with a dome on one side, thus promoting swirl. I have used '55 Buick pistons but they are 4", and not sure they have the ideal dome? Also stock B rods are plenty strong too, just don't use castellated nuts.

my4dv8 · 05-07-2019, 03:57 PM

Thanks for the reply Jim.
As regards the 55 Buick pistons ,is that the 322 pistons with the raised dome top?

Jim Brierley · 05-08-2019, 11:03 AM

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Yes, 322 pistons. At one time you could get them in 2 or 3 different ratios (dome height), probably available in only one now?

03-28-2019, 03:21 AM	#1
my4dv8 Senior Member Join Date: Aug 2010 Location: New Zealand Posts: 1,111	B4 with Cragar ohv and what rotating assembly choices We are still on a steep learning curve to 4 bangers ,( know our way around V8s well) We want to build a B4 into a decent runner to give the banger knockers a fright,and give us a big smile. We already have a nice Cragar OHV set up, but are interested in folks thoughts on the full rotating assembly . We know we will be full pressure oil etc. Jim Brierlys book touches on it for OHV but doesnt give detailed info. We want to run 60 mph all day with 3.5 rear gears and 750x16 tyres. We know we will have the odd hurried sprint but no extended high speed time just spirited street driving, maybe ,unless we weaken to more short outbursts for fun. We think higher compression pistons may help ,aiming at 8 to 1. But dont know how to get there. Is a new scat crank and some new rods necessary. We have a Brierlys cam for what he recommended for our planned combo. Need to check numbers on that. We have Twin 81 strombergs and headers along with an FS ignition. But thats as far as we know. We just want a solid reliable hard runner. Last edited by my4dv8; 03-28-2019 at 03:28 AM.

03-28-2019, 01:01 PM	#2
Jim Brierley Senior Member Join Date: Jun 2010 Location: Temecula, CA Posts: 4,088	Re: B4 with Cragar ohv and what rotating assembly choices Scat cranks are nice but not needed for what you are doing, a "C" crank will be more than adequate. Full oil pressure isn't mandatory either, stock oiling is good to at least 4,000 RPM. If your Cragar is an old iron one, the combustion chamber has no shape, so doesn't promote any swirl of the fuel mixture, resulting in LOTS of spark advance needed. 8:1 would be good, I'd do it with pistons with a dome on one side, thus promoting swirl. I have used '55 Buick pistons but they are 4", and not sure they have the ideal dome? Also stock B rods are plenty strong too, just don't use castellated nuts.

05-07-2019, 03:57 PM	#3
my4dv8 Senior Member Join Date: Aug 2010 Location: New Zealand Posts: 1,111	Re: B4 with Cragar ohv and what rotating assembly choices Thanks for the reply Jim. As regards the 55 Buick pistons ,is that the 322 pistons with the raised dome top?

05-08-2019, 11:03 AM	#4
Jim Brierley Senior Member Join Date: Jun 2010 Location: Temecula, CA Posts: 4,088	Re: B4 with Cragar ohv and what rotating assembly choices Sponsored Links (Register now to hide all advertisements) Yes, 322 pistons. At one time you could get them in 2 or 3 different ratios (dome height), probably available in only one now?