solid rollers and valve lift [Archive] - Chevelle Tech

: solid rollers and valve lift


sheetmetal
Dec 16th, 03, 7:40 PM
Im in the process of putting a contengency plan together for my 383. my current head set up with the hydroller is good to .600 lift, this is with the +.050 valves. if i go to a solid roller will i have to go to +.100 valves to get over the .600 lift "OR" can i select a spring that will allow the proper springs pressurs and more lift room? thanks Dave

DragRacer
Dec 16th, 03, 9:06 PM
Dave,

What is your current installed height? You may be able to just go with an "offset" retainer and get the room you need.

Don't forget to subtract lash when looking at solid roller profiles. Most of the .630" lobes are around .026-.028 lash, which puts you down around .600" net lift.

What size (cc) are the ports on your heads? What cam(s) are you looking at?

Wolfplace
Dec 16th, 03, 9:12 PM
Originally posted by sheetmetal:
Im in the process of putting a contengency plan together for my 383. my current head set up with the hydroller is good to .600 lift, this is with the +.050 valves. if i go to a solid roller will i have to go to +.100 valves to get over the .600 lift "OR" can i select a spring that will allow the proper springs pressurs and more lift room? thanks Dave You will find most of the better roller springs have an installed height of around 1.900-2.00" or better ;)
So it depends on where you are now, I would guess 1.800 or so.

sheetmetal
Dec 16th, 03, 10:05 PM
yes my installed height is 1.800. my heads flow to .700 lift but only gain about 4-5 cfm more after .600. the 195s finnished out at 210 after the porting and 66cc chambers. im not sure about what size solid roller yet. the car reminds me of a wind-up toy. goes like a bat for the first few hundred feet then just runs out of steam. ive only got 1200 rpm between the converter and valve float so im a little dissapointed. i guess i should have never rode in Johns car, spoiled me big time. so is the concensus pull the heads and redo the valves to be safe?

JOHN WILSON
Dec 16th, 03, 10:12 PM
Dave, 1.8 is plenty. Both Comp and Lunati have listings that will install at 1.8" with ~210 on the seat and 550-575 over the nose (with ~.620 net lift). Also, don't forget that most titanium retainers will net you an extra .050". Absolutely no need to change valves IMHO. Unless of course AFR uses cheapy valves that won't hang with the seat pressures and I would REALLY find that HARD to believe. I'm using a Lunati 1.50" spring installed at 1.80 and coil binds at 1.080". I have no issues with the .633 net lift cam I'm using. Also, don't be scared to put some spring on it! Too much is no problem, too little is trouble.

Wolfplace
Dec 16th, 03, 11:27 PM
Yes, a 917 Comp among others will work for your deal real well at 1.800 as long as you don't intend on running more than about .650 net lift.
I really prefer Isky's Tool Room Springs for most of the roller stuff I do & they start at about 1.900 & 230 or so lbs.
I agree completly with John about using lots of spring pressure on a roller. In my opinion the worst thing you can do to a roller is to run light springs on it.
Also, do not skimp on rollers. Isky's Red Zones & Crowers with the oiling option would be my first & second choice. The Isky's come with pin oiling standard.
And no,,, AFR does not use crappy valves :D
BTW, you will break a hell of a lot more valves with weak springs then stiff ones ;)

DragRacer
Dec 16th, 03, 11:36 PM
Dave,

Run that puppy at the track before you go making too many changes graemlins/thumbsup.gif

sheetmetal
Dec 17th, 03, 12:03 AM
Jason, thats the plan. got the trailer ordered now. the track shuts down for x-mas and opens again in January sometime. finally got everything done on the car so im ready. no rollbar yet so will be limited to 1/8 mile. hope it at least turns some 7.50s first time out. the goal is 7.30 Dave

sheetmetal
Dec 17th, 03, 4:53 PM
pulled the build sheet on the engine today and looked at what the springs set up. im confedent only one set of valves were checked. intakes set up at 1.865 and exaust set up at 1.855. 1.530 dia. springs. set pressure is 160# closed intake and exuast 350#intake 380# exaust.

hoffbug
Dec 17th, 03, 9:55 PM
AFR uses valves from REV.. Good stuff

Wolfplace
Dec 17th, 03, 10:58 PM
Originally posted by sheetmetal:
pulled the build sheet on the engine today and looked at what the springs set up. im confedent only one set of valves were checked. intakes set up at 1.865 and exaust set up at 1.855. 1.530 dia. springs. set pressure is 160# closed intake and exuast 350#intake 380# exaust. I would suggest lowering the pressure by about 25-30lbs. :D
Also, you have plenty of room for a roller spring at that installed height when you get ready. ;)