[tc]

Originally Posted by TCSGTO

Swapped a RAIV for a 247/252 112 Crower SFT in a .030” over 455 and gained nothing. It ran identical times and drove on the street the same. In my case it acted like a solid flat version of the RAIV.

Originally Posted by joes455

Made the switch from a ram air 4 cam solid lifter to a Crower 60311 solid 48 52 duration picked up very little

I have the 60311 on my list for the other 428, guess I'll take it off.

Originally Posted by jamaca85

as expected you would lose some bottom end switching to a hyd from a solid cam. the solid cam has a true 532 lift. the hyd lift due to the lifters you lose about .30 lift or more . so that 470 lift cam ends up being a 440 lift cam. less lift =less power for those ported heads....

I did not know that we lose .030 lift with hyd lifters.

Originally Posted by HWYSTR455

The 919 does give up earlier than one would expect though, you may just be seeing typical results. With your setup, you can easily go bigger.

My understanding is that with iron heads, depending on the porting, you generally don't see much flow gain over around .500-.525 lift. So duration is your friend with iron heads. In stock form, iron heads' flow rounds out @ .470-.490 lift. At least that's my understanding..

The longer duration idea is why I put the 60919 in.

Originally Posted by steve25

34 degrees total is low for the closed chamber in the 670 heads.I would have liked to have seen you try 38 had it not rained on you!

I should have just posted iron heads as I opened up the chambers on these 670's

Originally Posted by Cliff R

The 60919 cam is a bit too much for a 428 build with only 9.7 to 1 compression, but should be OK. The 428's are considerably more efficient that the undersquare 455's so I like to tighten up the LSA some and put more cam in them. They will easily make the power numbers of a 455 without a lot of additional RPM's.

I can see that a RAIV size cam would produce a "flat" power curve in a 428 and not surprised it doesn't really work quite as well as expected. 12.20's still isn't bad for the combination....IMHO......Cliff

My worn lobe SFT cam was 110 LSA. I'd like a better idle, so I thought I'd try 112 or 113. I was hoping I'd get some et's from others as this cam is talked about a lot.

Originally Posted by Lee

With a somewhat similar UD 288/296 cam in my old 455, I lost e.t. rapidly if I shifted past 5300.

IMHO start low on shift points, and work your way up. No sense in exposing your engine to unnecessary RPM.

I will next time out!

Originally Posted by STEELCITYFIREBIRD

....Impending rain I'd think makes for some "bad" air

Yeah, hit rain when I arrived at the track 1&1/2 hour drive. Sat for an hour, cleared up enough for two test runs, then started raining again.

Originally Posted by ponchorob

what makes me wonder that you lost 5 mph changing to 60919 cam...

Hope to figure that out too.