BBC cam & Valve spring questions??

[ClassicComp]

I put together a 402BBC w/spare parts closed chamber ret ports about 12.5-1 cr for my twice a month bracket car.
The question is how much spring pressure to run as it is a cast core street type roller cam.

Specs are Int .656 244°@.05 & Ex .676@256° ona 110°LS
This was a stick I had taken out of a job and is in fine shape hopin to run high 10's @3200lbs on alky .

[ClassicComp]

69 views and not 1 comment??
whats the site commin to......

[bigjoe1]

I have run 185-190 on the seat, and 500 open and never heard baack from the customer on the cast steel roller cores.

JOE SHERMAN RACING ENGINES

[Keith Morganstein]

69 views and not 1 comment??
whats the site commin to......

Normally I might run a comp 944-16 on that, but it's a Predator cast cam core. I'm not sure how much it can take.

A lighter spring like a comp 953-16 might work.

[Ed-vancedEngines]

That is a healthy cam for that small of engine unless you are going to buzz it up there. I just flat won't do black roller cams. I will suggest though to do 170 to 180 on seat and an open of around 500. Mr Joe has done them so he is probably right.

Ed

[UDHarold]

Back in the 1980s I had a customer running 10.68 with a 3200 lb Camaro with a 402 in it. His cam was an UltraDyne FLAT TAPPET BB296/304F8.

I recommended 135lbs on the seat, 335lbs open, give-or-take 5lbs either way.
The cam was 263/271 at .050", and .630"/.630" gross valve lift, 108 LSA, in the engine on 102 ICL.
It ran only 10.96s with a Holley 110 and 1 regulator. Changing jets would not help.
I had him change to 2 regulators and a Y-Block, and a Moroso helper spring in the Pump. It ran the 10.68s the day he changed.
The 296 has gone 100,000 miles on the street as a 288/296F7 or F10.
The 304 is a little milder.......

UDHarold

[ClassicComp]

Harold,
This is a Roller cam and I gonna gear it to run around 7200 in the big end
depending on what it dynos at.