[RAM YAK II]

O.K. you guys. I've been reading your posts since the "old board" days, gleening all the information I could until I could stsrt my project. I just got my 6X (4) heads back from the machinist where he cleaned, magnafluxed, checked the guides, did a three angle cut on the seats, checked the installed heights (1.600 mostly) and cut the spring seats for CC 995 springs. Well, he did everything except the spring seats. He was afraid he would hit water if he cut them .100" to get me to 1.700". I am running a Crower 297 HDP cam with 297/308 and duration .501 lift with 1.50 Harlan Sharps and .551 with Crane Gold 1.65's. I'm using stock length Ferrea s.s. valves (2.11 and 1.66). Is there anything cast in stone that says I have to install them at 1.600 or 1.700 or can I install them at, say 1.650? What are the chances of him hitting water at .100? Can I have them cut .050 and use .050 taller retainers? What kind of problems would I see if I used .148 (Crane) taller retainers and did no machining? I'm going to CC them before I take them back to him so any help you can give would be appreciated. And hey, no yelling at me. This may have been discussed before but I couldn't find the answer in my notes or printings from the earlier postings. Thanx in advance. RAM YAK II

[RAM YAK II]

O.K. you guys. I've been reading your posts since the "old board" days, gleening all the information I could until I could stsrt my project. I just got my 6X (4) heads back from the machinist where he cleaned, magnafluxed, checked the guides, did a three angle cut on the seats, checked the installed heights (1.600 mostly) and cut the spring seats for CC 995 springs. Well, he did everything except the spring seats. He was afraid he would hit water if he cut them .100" to get me to 1.700". I am running a Crower 297 HDP cam with 297/308 and duration .501 lift with 1.50 Harlan Sharps and .551 with Crane Gold 1.65's. I'm using stock length Ferrea s.s. valves (2.11 and 1.66). Is there anything cast in stone that says I have to install them at 1.600 or 1.700 or can I install them at, say 1.650? What are the chances of him hitting water at .100? Can I have them cut .050 and use .050 taller retainers? What kind of problems would I see if I used .148 (Crane) taller retainers and did no machining? I'm going to CC them before I take them back to him so any help you can give would be appreciated. And hey, no yelling at me. This may have been discussed before but I couldn't find the answer in my notes or printings from the earlier postings. Thanx in advance. RAM YAK II

[Brian Baker]

The springs you're using are designed to provide 115-120 lbs. of seat pressure with an installed height of 1.700". Installing them at 1.600" may provide too much pressure, which can accelerate lobe wear when using a hydraulic cam. I wouldn't machine the seats, leave them be. You basically have two choices to bring the installed height up to at least 1.650". Buy longer valves or buy offset keepers (locks). Obviously the offset keepers would be the cheaper route. Ask your machinist about them.

[Brian Baker]

Also, with that cam, if you intend to run 1.65 rockers, you'll be into coil bind with an installed height of 1.600".

[RAM YAK II]

I hadn't thought about the coil bind factor at 1.600.....glad you mentioned it. I think I'm gonna make sure of the current heights and if they are indeed 1.600, I'll get the offset retainers and spend the machining money somewhere else. Do I need to be concerned about the rocker to retainer clearance more with this setup? I do intend to measure at the highest lift plus the before and after open points. Also, I did a trial fit of the 995 springs before I had the heads cleaned and noticed the inner springs were snug on the valve guide. Is this a concern? The machinist didn't think so but he runs an '83 Firebird with a (gasp) corporate engine. Think he can be trusted?
Thanx for the response to my other post Brian. RAM YAK II


Seen it all, done it all, can't remember most of it.

[Brian Baker]

I have the same springs on my 6X heads and they fit fine. Do you mean the inside diameter of the inner spring is rubbing against the valve guide? If you can drop the spring on there and it's just "touching" this shouldn't be a problem, but if you have to "force" the spring on there, it will be a problem. Hey, if money permits, while you have it apart, have your machinist cut down the valve guides above the spring seat and install PC type guide seals. They work alot better than the factory O-ring type.

[Brian Baker]

You shouldn't have a problem with rocker/retainer interference with using either 1.5 or 1.65 rockers, HOWEVER!!! If using the 1.65's, check and double check to make sure (1.5's won't be an issue).

Also, if using the 1.65's, you'll have to enlarge the pushrod holes in the heads to keep the pushrods from "chaffing" or "binding" against the head (very bad, very bad). They don't need to be round, just egg shape the pushrod hole, removing material from the side of the hole closest to the rocker stud.

[RAM YAK II]

Hey Brian, I have been weighing your advice and have decided to try to exchange my "short valves" for some longer ones. They are un-touched except for getting installed heights so I hope the vendor will make a swap. I can't do anything until Monday but I'll let you know. Thanx again for the advice. RAM YAK II Doug Brown


He who hesitates is not only lost but miles from the next exit.

[PONTIAC DUDE]

Don't know about .100, but you can cut them .060. Then run the offset keepers.

------------------
NOS is like American Express.....You don't leave home without it.
http://www.angelfire.com/fl4/pontiacdude428