I remember reading this somewhere. Is this doable and/or recomended. Some of the hyd roller cams are more friendly with EFI than the solid cores are.

 

I called comp cams about my XE294HR and they said that it could use solid roller with very tight lash settings. Something like .08 - .010 hot.

It worked OKay until the cheap *** pot metal Comp Cams fuel pump lobe went flat. Just a **** poor product.

For just a few more dollars have a custom billet with the sleeved dist gear made. You go the CC site and go the pages of lobe types. The more radical the ramp rate, the more area under the curve creates the highest vacuum for a given lobe/ LCA combo. Intake reversion is what kills the computer sensors ability to keep up on the A/F mix.

You under stand the H-flat with the mildest ramps is the worst offender as duration goes up and Lobe Centers numbers go down. that why a 240- 250 intake duration flat cam sounds like a race car at idle and a solid roller just purrs along.

So you want the more radial ramp rate solid and just have it ground on 112 or 114 centers. I also have mine cams ground straight up without the 4 degrees of advance. that also makes for less reversion because of the later intake opening. I would also get the new firing order models. I do have a Crane SR sleeved 232/240 112 that was pretty mild in my 383 even with 1.6's if you would like to try it.

 

I think I'm probably better off having one custom made. I like the 112 to 114 centers. The new firing order would not be much of an issue, just have to have the computer reprogrammed. What would this do for me changing the 4/7 swap though. I'd like to try that cam but I'm afraid it might be a little short on duration and run into detonation. I'm thinking more along the lines of high 230s on the intake and mid 240s on the exhaust side. Maybe even 240 on the intake.

Tried Comp Cams 3 times today and just got a busy signal.

 

my 383 now has 236/242 112 straight up without detonation on California max 91 octane With 1.65 intake 1.6 exhaust it is something like .620/.620

 

Is this a Crane cam or a Comp XE? glad to hear that the sale of Crane went through so hopefully new product will start to hit the shelves soon.

 

GKULL did you use a roller pushrod for the fuel pump?I have one,it has a roller at one end of the rod,it rides on the cam lobe and flat at the other end that goes against the fuel pump.It has a slit through the rod for a keeper pim to hold the rod straight.If this is what you used,tell me all about it,i may have to take it out of mine Sorry Gordonm for the intrusion .

 

I have one of those roller pushrods on my CC cam. It is a billet core though.

George is talking about the off the shelf cams that are made of concrete with a thin layer of metal over top the lobes.

If you ever buy a Comp Cam always specify you want a billet core with a pressed on iron gear, mine only cost about $40 more and it was a custom small base circle and they can machine them and get them to you in less than a week

Which one would you want in your motor, top one is billet and bottom one is concrete or some unknown substance



Here's my solid roller $40 extra for a work of art

 

For pot metal CC cams you have to run the bronze tip or roller tip pump rods. It is in their disclamer now.

 

Motor head brought some good points. You have to get the very small base circle like his extreem example. Sub .900 for rod clearance on stroker motors with bigger 6 inch rods

 

This is hard to find on their site, but choosing your own lobes on a custom cam is very rewarding. this is how I made my present big lift endurance road racing lobed .685/.714 relatively small duration 248/250

Then you buy just under .800 lift dual springs and set the installed height to lower the spring pressure to near 200# closed

http://www.compcams.com/Technical/Ca...obeCatalog.pdf

 

I've asked that question a couple of times here. No real good reason given for the 4/7 swap, but there must be a reason they make that firing order an option. There must be a reason GM went with the new firing order on the LS engines. Gordon, why would you have to reprogram for the 4/7 swap. Just swap the #4 spark plug wire for the #7. I guess with FI, you don't need to worry about the fuel pump rod.
Bee Jay

 

It is not just the ignition with the computer it is also the firing of the injectors. They have to be timed correctly also.

 

Oh, OK. I guess I don't have to worry about that with my throttle body injectrion. So your FI is seqential port? What is your injection system again? Also, what is the big advantage or what is gained by doing the 4/7 swap?
Bee Jay

 

Not to sure on the 4/7 swap. Maybe someone else can expain. I know the LS series motors have this firing order and they run very good. Not sure of the advantage on the GEN 1 SB. The system I am running is a Mass Flo system and it is sequential port injected.

 

i think this swap changes the harmonics on the crank putting less stress on the crankshaft ????

 

Hey Gordon, my latest issue of Hot Rod magazine arrived last night and it talks about running solid roller lifters on a hydraulic roller cam. They actually picked up power over the hydrualic roller lifters.
Bee Jay

 

Solid will almost always pick up power over a hydraulic...with Gkull on the billet piece, spend a tad more and go billet.