Author Topic: what rear cam and gear with bbc  (Read 6463 times)

Offline crider

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what rear cam and gear with bbc
« on: January 01, 2016, 01:49:38 PM »
Hi, new guy here. I just bought a chassis from David Beard and I'm starting to gather parts for the build. I'm using what I had around for as much of it as possible. The engine is going to be a 511bbc, 4.375 bore x 4.250 stroke. Tall deck truck block. Ported cheapo pro-line heads. I'll be doing mostly 1/8 mile racing in my area. Looking for some cam and gear suggestions. I've drag raced off and on for years, but this is my first time running anything this lightweight. Thanks for any input   

Offline dusterdave173

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Re: what rear cam and gear with bbc
« Reply #1 on: January 01, 2016, 03:38:10 PM »
Start with rear tire height but usually in big block it comes down to a 4.10 range gear
That many CI will love something in the 280/285 at 050 and make enough torque to flip it over twice
You running Stack injection or TR and Hat?  Keep CR up at least 13.5 and more is always better--on gas engines folks have heck of a time jetting with high compression and can toast parts easy-- but on alky it is easy as pie--  14:1 and up runs real good! That combo will be a beast---lighter cars like these are very forgiving with converters-loose is good--real loose is good too! Crazy loose still works good! Slap about any 8 in you have in there and go for it
Concentrate on Good quality fuel plumbing / stainless filters and keep it hospital clean  many folks clog up new cars with debris in new made hoses---look at a nozzle--it don't take much . Keep tank up just a tad--gravity is your pal--  Speedway Motors makes a great 3 1/2 gal aluminum Moon copy for under $170

These cars are very forgiving on tire diameter/ stall/ cams/ etc     They want to haul hard with just about anything you put in them---makes it Fun!  They are Nothing like a heavy door car that has to have the perfect converter / gear combo

Mike Chilando at Alkydigger in TN is a great source for injection/plumbing new and used--super guy!!
I have always had a fascination with fast cars at the expense of more normal character development

Offline crider

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Re: what rear cam and gear with bbc
« Reply #2 on: January 01, 2016, 04:07:13 PM »
I'm thinking 33" on the rear tires. It's going to most likely get a carb until I get things sorted out, then switch to stacks. This engine is going together with leftover parts from my funny car  and thanks to that I'm kinda stuck with the compression ratio without spending money on another set of custom pistons. I learned all the lessons on keeping things clean with the funny car. That thing drove me crazy when I first when blown/injected

Offline dusterdave173

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Re: what rear cam and gear with bbc
« Reply #3 on: January 02, 2016, 05:45:08 AM »
I run the 33 in MT's they work just fine  with my small block and a 4.22 gear I found I needed more gear like a 4.56 or shorter tire for best setup--I have not changed it and probably will not for while---just having fun!
I have always had a fascination with fast cars at the expense of more normal character development

Offline wideopen231

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Re: what rear cam and gear with bbc
« Reply #4 on: January 02, 2016, 06:46:32 AM »
I'm going with 32 tall mt and 4.11 for starter. will adjust from there. I think the 280* cam is pretty close as long as your heads will support the rpm.As for starting with carb,I would not.If you plan to run injection why have to retune everything after getting it close.You have experiance with injection so it should be simple to get dialed in.JMO.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline ricardo1967

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Re: what rear cam and gear with bbc
« Reply #5 on: January 02, 2016, 02:45:46 PM »
"... As for starting with carb,I would not.If you plan to run injection why have to retune everything after getting it close.You have experiance with injection so it should be simple to get dialed in.JMO.

I agree 100% with Chris. That what I did, no regrets.

Offline msundstrom

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Re: what rear cam and gear with bbc
« Reply #6 on: January 02, 2016, 08:05:23 PM »
My combo is similar to yours but 9.8" deck with cheapo EQ iron heads but a splash of nitro with stack injector, 11.7:1 , 33 x 12 tire with 3.89 gears, glide with a TIGHT converter. I run only 1/4 mile so 1/8 mile gearing is probably different. Will probably be trying a 3.50 gear in the near future though. Did you specify your transmission option? Oh yes cam is 272/276 duration @ .050".
Mark

Offline crider

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Re: what rear cam and gear with bbc
« Reply #7 on: January 03, 2016, 05:15:43 AM »
Msundstron, Sorry I did forget to specify what trans, but it's going to be a glide

Offline masracingtd1167

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Re: what rear cam and gear with bbc
« Reply #8 on: January 03, 2016, 05:51:38 AM »
I would use the same gear you would use for 1/4 mile . If you go too low with your rear gear it might make the car too violent on the starting line . I have seen a couple of David Beard's cars and they look really nice ! Good luck with it !