[DragRacr]

Does anyone know how big on duration or lift before valve clearance is a problem? Comp recommened 35-780-9 for my 408w. Its a solid roller with 268,275 @.050 and 696, 672 lift.Wondering if i'll have to fly cut the pistons or will it work.Does anyone have anything similiar they put together that can give me alittle info?

 

[dfree383]

Its not duration, its in the timing of the events, you will have to check by installing the cam and putting clay on the pistons and turn the motor over by hand and measure it.......................

 

[coolfalcon]

Hmmm wonder how many cams he would have to buy before he found the right one?

 

[mavman]

Timing events have more to do with valve-to-piston clearance than anything else. Valve reliefs are also a concern, but most of the aftermarket pistons available will accomodate 2.08" or larger valves....just have to make sure. I've seen some cheapie TRW's and KB's with valve reliefs so small that a 1.94 won't clear...and they're advertised to "work" with high lift / long duration cams and larger valves.

Only way to know for sure is to "clay" it as suggested.

 

[DragRacr]

First of all coolfalcon the solid lift i put in which was FW 276FLS-6 comp cam, .584,.592 lift @ 240 ,250 got ate up on break in! Found out the vic jr were suppose to come with 130lbs of seat and 380 open pressure but after the cam failure i got them checked and they where off at 170 at the seat and high 400's open.Which i guess too much for break in.Cost me bearings, and other parts.I have learned my lesson the hard way.Always get the springs checked nomatter what the paper says or what the people say or your taking a big chance.So i want to go solid roller now instaed of the solid lift.This is the cam Comp cams came up with for my setup.35-780-9

<font size=-1>[ This Message was edited by: DragRacr on 5/3/06 10:42am ]</font>

 

[DragRacr]

The pistons are SRP 11.7 to 1 flat tops.They have fairly large reliefs.They are cut for a 2.08.

<font size=-1>[ This Message was edited by: DragRacr on 5/3/06 11:14am ]</font>

 

[pinto306]

If you want to be sure and safe, CHECK IT!
I just had my engine mocked up by a highly recommended shop and got home and checked it myself. If I moved the centerline of the cam and installed it like the manufacture said to I needed to remove an additional .080 to have good clearance on the intake side.
CHECK IT!

 

[forthman]

You are just going to have to check it. You cannot guess. Head/piston/valve setups vary vendor to vendor. So you need to check it to be safe and not sorry.
My guess is when you check it you will find it is ok.

_________________
1966 Stang Coupe Org. 6 cyl. 351w,Sealed Power Hypers, ARP bolts,Total Seal rings,Eagle H-beams rods,Balanced,Hedman long tubes, TMD 2.05/1.60 Vic Jr Knockoffs, 1.6 Stainless steel Roller Rockers, Victor Jr intake, Holley 750 DP, Ed Nix Custom .600/.600 254/258 @.050 Solid Cam, Crane solid roller lifters,Richmond 4.11, Strange mini spool, Modified C4, 3500 stall, ******* Transbrake, B&M Hammer shifter, Shelby lowered, Pro-Comp 6Al system. Mickey Thompson 275/50 Et Street Drag radials.

<font size=-1>[ This Message was edited by: Forthman on 5/3/06 1:00pm ]</font>

 

[mavman]

Pretty close to mine...VJr heads, 414" windsor, but I run Mahle pistons and not the SRP's...but I did mock up some SRP's before I decided to try the Mahles (also went with a different rod combo) and they cleared fine. My cam is 277-282 @ .050, solid roller and .700 lift straight across. Going to go back to my old cam though, this one is a little too hard on springs and likes a little too much RPM.

With the SRP's I had .122" intake and .115" exhaust clearance, with the old cam (270-274 @ .050, .700 lift, 104 centerline). The Mahles have a little more at .125 and .120" respectively. Plus they're lighter...by about 50 grams

 

[pinto306]

mavman, what was your old cam? What kind of drag racing time diff. was there?

 

[tonys10sec306]

install cam and check