BBC SR20's - need to know how good?

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David Vizard
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BBC SR20's - need to know how good?

Post by David Vizard »

I have not been able to do any dyno testing on SR20 BBC cylinder heads.

I am doing a BBC porting video and I feel I should cover these heads in reasonable detail. They have a reputation for making better than average race power. Can anyone confirm this???
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mt-engines
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Re: BBC SR20's - need to know how good?

Post by mt-engines »

they are an easy 1050hp with a single carb mild compression ratio and a cam under .800" lift
racear2865
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Re: BBC SR20's - need to know how good?

Post by racear2865 »

Im building a 631BBC for a customer. I can give u the flow numbers tomorrow when I get back in the shop. have the intake also and 600 hp nitrous
reed
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Re: BBC SR20's - need to know how good?

Post by bob460 »

Alex Hays in his mustang ran 4.60s in 1/8 NA 588ci Uratchko built heads by Slick Rick..........Badass!!

https://www.youtube.com/watch?v=a8xNDPU6Eq4

Shafiroff make a crate engine 632 with 10.7 comp pump gas 1050hp.
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Re: BBC SR20's - need to know how good?

Post by prairiehotrodder »

I've heard that the BR20's are the poor mans version and have alot to offer.
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racear2865
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Re: BBC SR20's - need to know how good?

Post by racear2865 »

450cc
96cc chamber
2.400/1.800
4.600 fixture
2.125 pipe
.200 164/123
.300 232/171
.400 310/214
.500 380/255
.600 435/296
.700 485/316
.800 499/330
.900 512/339
1.00 516/344
sr20.jpg



this is with 50 degree seats and not 55
reed
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Re: BBC SR20's - need to know how good?

Post by ClassAct »

David Vizard wrote: Sun Jan 31, 2021 1:31 pm I have not been able to do any dyno testing on SR20 BBC cylinder heads.

I am doing a BBC porting video and I feel I should cover these heads in reasonable detail. They have a reputation for making better than average race power. Can anyone confirm this???
DV

Can you check your PM’s David?? Thank You.
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Re: BBC SR20's - need to know how good?

Post by Abbottracingheads »

They are significantly better than regular bbc heads.
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Re: BBC SR20's - need to know how good?

Post by AA Performance »

racear2865 wrote: Mon Feb 01, 2021 1:11 pm 450cc
96cc chamber
2.400/1.800
4.600 fixture
2.125 pipe
.200 164/123
.300 232/171
.400 310/214
.500 380/255
.600 435/296
.700 485/316
.800 499/330
.900 512/339
1.00 516/344
sr20.jpg




this is with 50 degree seats and not 55
reed
Just wondering how much the steeper valve seats are worth. I think the Brodix SR20 have a 50° intake and 55° exhaust seat or am i wrong? Does any one know how the BRX as cast heads compare as they seem as they are as good as the CNC ported and only drop off at .700" and up slightly? The original topic didn't seem to get into it very much and was short lived.
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