[70 beater]

I'd like some feedback on these if anyone is using them.Solid flat tappet.I'm cam shopping for one maybe 2 engines.My engine(s) meet the parameters outlined in the recommendations,also torque converter.Gears aren't exact,but close-3.73 and/or 4.56.Street strip car.Comp 294S currently,248 @ .050,.595",110/106.

402A4LUN: * Advertised Duration IN/EX: 282/292
* Duration @.050 IN/EX: 248/255
* Gross Valve Lift IN/EX: .570"/.586"
* Lobe Sep Angle / Intake Ctr Line: 112/106
* Valve Lash IN/EX: .020"/.022"
* RPM Range: 2800-7000

402A5LUN: * Advertised Duration IN/EX: 285/295
* Duration @.050 IN/EX: 252/261
* Gross Valve Lift IN/EX: .595"/.595"
* Lobe Sep Angle / Intake Ctr Line: 110/104
* Valve Lash IN/EX: .025"/.025"
* RPM Range: 3000-7200

[wildman926]

Hey Jon,

HERE is a link of someone's engine idling with a 402A7Lun, which is just a tad larger than the A5. Mr. Harold Brookshire recommended that cam for me when I was going solid ft for my 496 build. Here is what he said:
"Walter,

The 402A7LUN is what I recommend for most street BBCs, and I have dynoed with as low as 9.2 CR---468 cid, 561 BHP @ 6400. The 402A6LUN is the same cam, ground on a 107 LSA, and the original. It is a real handful on the street, the 402A7 is much better driving in traffic, as well as liking a 3000 SS converter."

Something to think about. You don't have to be dead on with the requirements, those are "optimum" recommendations. I am .4-5 under the recommended compression with my 401A6Lun, but it runs exactly as described by Harold, and is a blast to drive, pulls extremely hard.

Aren't you building a 496? Those recommendations for the cam you are reading actually become applicable for the next larger cam due to the cubic inches making the cam you are looking at "seem" smaller. In other words, the rpm range and stall requirements drops about 400 rpm from the "recommended", gear requirements drop down to the next like from 4.11 to 3.73, compression requirements drop .2-.5, etc.

[70 beater]

Thanks Walter.
Here's the spec.s on those cams:
402A7LUN: * Advertised Duration IN/EX: 288/296
* Duration @.050 IN/EX: 255/263
* Gross Valve Lift IN/EX: .612"/.630"
* Lobe Sep Angle / Intake Ctr Line: 110/104
* Valve Lash IN/EX: .024"/.026"
* RPM Range: 3000-7000

402A6LUN: * Advertised Duration IN/EX: 288/296
* Duration @.050 IN/EX: 255/263
* Gross Valve Lift IN/EX: .612"/.630'
* Lobe Sep Angle / Intake Ctr Line: 107/101
* Valve Lash IN/EX: .030"/.030"
* RPM Range: 3000-7200

I had looked at those and they have a little more lift than I was looking for.This first engine will be the 402 more than likely,which has closed chamber heads and domed pistons,that I was concerned with clearance on,don't know if shrouding will play into it or not.It's 10.3:1 if I remember right.

He (Harold) didn't mention anything about n2o and those cams did he?

[wildman926]

Jon,

A5 it is if you are having concerns with P-V clearance. I thought about that after I posted. He did not mention an n2o, because I did not ask about it. Correct me if I am wrong, but with n2o, you need more lsa, and wouldn't that would call for the A5 to be ground on 112-114? You can order it, my 401A6lun is on 112 instead of 110.

Love that converter!!!

[427L88]

Harold has said that widening LSA on cams isnt required unless the NoS shot is big.

[70 beater]

thanks guys
I'm really leaning towards the A5 also,I think the lsa will be better on the street also.I'm not planning on going over 200 on the spray,may not even spray that much.My thinking is that 200 and less is a small shot.

I love my converter also!!

[wildman926]

Jon,

Honestly, you will not go wrong using any of Harold's cams!!!