[Fstarocka]

Hi all - busy getting ready for the 393 build .. opinions on this cam? got the kit for 100 bucks, I think it will be a good balance between a driver and red light machine -

stock 1970 block 30 over, hyper speed pro pistons, stock truck football rods, 11:1 pro comp copy 185cc heads, 3.85 stroke eagle crank, LT headers, Rpm dual plane intake, 750 vac secondary (might try quadrajet on this one if theres space

Edelbrock 7122:

Advertised Exhaust Duration	300 deg
Advertised Intake Duration	290 deg
Intake Duration .050 Inch Lift	224 deg
Exhaust Duration at .050 inch Lift	234 deg
Exhaust Valve Lift	0.520 in
Intake Valve Lift	0.496 in

 

[Fstarocka]

Having read comparisons with roller vs FT im strongly considering going with the roller and just pony up the cash for the linked lifters :/

 

[nyceguy01]

I only do hydraulic rollers these days.
They just flat out work great.
You also dont have to worry about the correct oil or additives with ZDDP.
Except for the one down side of initial cost there are only up sides then on out.

 

[chris3353]

Hi all - busy getting ready for the 393 build .. opinions on this cam? got the kit for 100 bucks, I think it will be a good balance between a driver and red light machine -

stock 1970 block 30 over, hyper speed pro pistons, stock truck football rods, 11:1 pro comp copy 185cc heads, 3.85 stroke eagle crank, LT headers, Rpm dual plane intake, 750 vac secondary (might try quadrajet on this one if theres space

Edelbrock 7122:

Advertised Exhaust Duration	300 deg
Advertised Intake Duration	290 deg
Intake Duration .050 Inch Lift	224 deg
Exhaust Duration at .050 inch Lift	234 deg
Exhaust Valve Lift	0.520 in
Intake Valve Lift	0.496 in

That is alot of avertised dur for the .050 (must be hyd flat?)

My last three builds have been solid flats with the EDM lifter. Solid flats make power and have less valve spring pressures.
Before everyone piles on about oils, Call Comp, Lunati etc and ask one of the techs. I think the few flat tap failures come from too much spring. It is crazy how low a spring rate is needed to control a solid lifer.

 

[johnsongrass1]

Agreed, that cam is a long and slow. There are better ones to be had but it will still run.

FT cam, don't be scared. Use quality parts, the right springs, break in procedures, a break in oil, and the likely hood of a failure is really low.
I still prefer a roller givin the option.

 

[Fstarocka]

wouldnt a longer dur indicate quicker ramps? Anyway i dropped a roller in yesterday.. found a deal on edelbrock linked lifters for 300 i couldnt pass up. Got bottom end clearanced and together and the wife did all the basic assembly after i clearanced all the pistons and checked everything

 

[ericnova72]

wouldnt a longer dur indicate quicker ramps?

Nope.
The 70° difference between advertised duration and the .050" duration is considered pretty slow ramp.
Everything Edelbrock sells(camshaft wise) is very old school and out of date.
Even their hydraulic roller stuff is not very aggressive.
A relatively quicK ramp would be 265° advertised 224° @.050"

 

[BogiesAnnex1]

wouldnt a longer dur indicate quicker ramps? ........”

No, the longer the total duration in relation to the .050 duration indicates a slower rise. as more degrees thus time is devoted to getting to the place where .050 lift is measured.

So the shorter the total degrees compared to .50 degrees the faster the ramp.

Bogie

 

[chris3353]

wouldnt a longer dur indicate quicker ramps? Anyway i dropped a roller in yesterday.. found a deal on edelbrock linked lifters for 300 i couldnt pass up. Got bottom end clearanced and together and the wife did all the basic assembly after i clearanced all the pistons and checked everything

View attachment 616023

You should at least use a basic dynamic comp calc before you choose a cam. Check out this one from Pat Kelly. the download link is near the bottom.

Dynamic CR

Or,, share the specs of what you are building?

bore and stroke
rod length
piston CC
head cc
compression height to deck
what is your elevation?

If you have flat top pistons and 65 cc heads you will be ~7.9 DCR. If your heads are in the 70s or a dish piston it will be a turd.