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solid roller and hyd roller springs the same?

2K views 6 replies 4 participants last post by  GOSFAST 
#1 ·
I have a set of 074 heads that are set up for a solid roller cam.I am going to use them on a 468 I am building for my 68 ss.I was going to use a flat tappet cam but due to the problem people seem to be having with wiped lobes and due to the fact my heads allready are set up for a roller I am thinking of going with a roller cam.This will be mostly used on the street and I am trying to decide hyd or solid.It would help me decide if I knew if a hyd roller and a solid roller used the same spring.I don't know what brand of springs they are but they are a tripple spring(outer spring,damper,and inner spring)My machine shop said they have about 200 lbs closed and about 450 lbs open.I have no problem spending the money for a billet cam with the cast gear and the isky red zone lifters.I was thinking of using a lunati 502a1lun or a 502a2lun cam.Or I could go hyd roller?Thanks Bill.
 
#4 ·
Careful using the old "074"'s with rollers

You have to make sure you have the 8 exhaust studs changed over to the extended lengths on the bottoms. The heads have to be drilled deeper to install the studs. ARP has the studs available under the part #235-7206 and matching intakes under the part #235-7207. You have to be very careful with the 2 studs that go over the heat-passage. When you drill the heads deeper here, make sure you don't go too deep or you'll end up in the water jackets. It's OK on the other 6 because they run directly into the water anyway and sealer is required. Only under the heat passages it becomes a "double wall" condition. You'll have to shorten the 2 studs on the bottom that goes in each of these 2 holes. One other thing, you should run seat cups/locators under the heavy springs and no spring shims. Bill, I think I sent you that oil pump spring awhile back? How you doin'? These heads are small runners (CFM-wise) but work good on smaller inch BB's. If you have any questions contact me. Thanks, Gary in N.Y.
PS If you don't do the stud modification you'll find youself possibly breaking the (exhaust) rocker stud stanchion right off the head. This was a "common" problem years ago. The "matching" part of the studs is the tops, where they give you extra material for use with roller rockers and poly-locks. If you use the exhaust only, you'll have have 2 different top heights, and will appear wrong when the set-screws in the locks are totally different hgts.
 
#5 ·
Re: Careful using the old "074"'s with rollers

Gary,I allready had the exhaust studs replaced with the long arp studs.I didn't get the intake studs but I can order them if I you think I need them.I had my machine shop install the studs and they double heili coiled the holes.They didn't say anything about the heat passage or haveing to shorten the studs I hope I don't have a problem they have been building race engines for 30+ years.It might be wise to remove those studs and make sure everything is ok.I recieved the oil pump spring but haven't installed it yet because I am still trying to decide about the cam.Thanks Bill.
 
#6 ·
Re: Careful using the old "074"'s with rollers

Gary,I just pulled the stud out that is over the heat passage and they are the same length as the others!I can't find anyplace where the drill went through the wall.I checked both heads so unless it has a pin hole some where I can't see I hope I am ok?The springs have a thin metal shim under them is that ok?Thanks Bill.
 
#7 · (Edited)
Hi Bill, they may have shortened them to avoid hitting water which is OK. If you look directly into the heat-crossover port and don't see any holes you're
good to go. Look at the bottoms of the exhaust studs and see if they shortened them all. In order to make use of the long bottomed studs, you actually have to go into the water jackets on the other 6 holes. If you shorten the studs too much, you defeat the purpose of the longer stud. Thanks, Gary in N.Y.
PS. I recommmend the taller intake studs also, you'll have more of the stud inside the poly-locks at the top, lessening the chance of breaking the tip of the stud off. The bottoms of the exhaust studs should measure about 1.625" and the tops should measure 2.000" from the bottom surface of the nut. Do the intakes to match the tops, they also measure 2.000" to the top of the threads. Hurry up and use that spring, it'll lose the tension layin' around! (Just kiddin') Just want to add: we always use cups or locators directly under the springs, especially roller pressures. If we need shims they go under the cups. You'll find the springs "tearing-up" the shims no matter whether they're heat-treated or not. The 450# number on a Hyd. Roller to me seems a bit high(depends on total lift at valve), we send them out with 400# @ .720/.730 lift. They go fine on the dyno to 6500RPM and is usually no reason to run 'em up there. We're seeing 6100/6200 peak power on most tests. We do run titanium retainers which helps, we're actually starting to use titanium intakes also, looking for a little longer spring life. Stay in touch!
 
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