am_muscl

iTrader: (19)

If a set of heads are set up for a solid roller cam, what would need to be done to make them work with a hydraulic roller cam?

Just a swap of the valve springs? Pushrods?

Any info would be great because I'm looking at a set and I wanna know what I'm going to have to replace to make them work.

Wicked94Z

iTrader: (26)

check the guideplates and make sure they're setup for a 5/16 pushrod. find out what the installed height is on those solid roller springs, that'll give you an idea of whats required to setup your springs on there. verify the valve stem diameter too...

joelster

Most likely just a spring swap. See if you can get the specs from the springs that are on there now. Usually solid-roller springs are monsters that will abuse a stock hydraulic lifter. Not always the case though.

am_muscl

iTrader: (19)

so I got the specs on these heads and i'm wondering if someone could tell me what the numbers exactly mean. I'm trying to compare flow numbers to some LE heads and I plan on doing the spring swap as soon as I get them, I have some pac beehive springs that are good to a .600 lift and my cam is not quite that high. I'm just wondering how it will run with my custom grind cam and these heads.

intake flow: exhaust flow:
.300 180 .300 126
.400 229 .400 154
.450 249 .450 181
.500 261 .500 193
.550 278 .550 203
.600 291 .600 206

duh

iTrader: (16)

according to the numbers they flow pretty good IMO. Are these stock castings??? IIRC there aren't many stock castings that have been hogged out to flow d*mn near 300 CFM at only .600..... Those are some nice looking heads and will make any big ci. motor really happy.....

Swap to the lighter springs with some 10* locks and retainers and have fun....JMO...

am_muscl

iTrader: (19)

^^^ how do you think they would work on a stock bottom end? I've got a ported intake, pretty healthy cam, but a stock bottom end.

RamAir95TA

iTrader: (2)

AI (and I think LE) both offer heads approaching 300cfm (~291cfm for 200cc's), so it isn't unheard of. Then again, that number doesn't mean jack without quality mid-lift numbers.

Since you have a stock bottom end and displacement, you're going to need to spin it pretty high to make maximum use of those heads.

am_muscl

iTrader: (19)

^^ well right now with the cam I have it spins up to about 6800 so I'm not too afraid of that, I also don't really plan on the stock bottom end lasting much longer with 132k miles, I just wanna see what I can get with these and if the motor goes, I'll just go with a rebuild of some sort.

I appreciate the feedback it is informative and helpful.

joelster

What is the oil pressure when you are idling and the motor is hot? If it's above 30lbs, then the shortblock will probably last quite a while. When you hear of some LT1 cars that have 10lbs of oil pressure when they are hot, those are the ones that i'd be afraid of spinning over 6000rpm consistantly. Those heads have some really good flow numbers to them. Your car should be a beast with them on.

am_muscl

iTrader: (19)

oil pressure is at around 40lbs I believe when it is hot, I have never really seen it below 30lbs.

The only thing that I really know that may need replacing overall is my cam bearings because those were slightly worn. Also with these size heads, I have almost new stock replacement hydraulic lifters, do I need to upgrade to like ls7 lifters or anything to keep up? I also plan on hopefully being able to upgrade to bigger injectors because I doubt the stockers will be able to hold up.

am_muscl

iTrader: (19)

I have another question about the valves on these heads. I found they are 2.05 and 1.57 and I wanna make sure that they will work with a stock bottom end without having to modify the pistons or do anything radical.

Does anyone know if they will work?

duh

iTrader: (16)

First off, keep a close eye on the cam bearings....I have a block in my garage currently with the cam bearings and cam trashed....infact I still have to try and get the cam out of the block.....secondly, you're probably going to be spinning really close to 7K to take full advantage of those heads. And with the 2.05/1.57 valves definitely make sure to use the playdoh method and check clearances when you put it together. IIRC you usually see those valves in 4.125" bore applications, otherwise you end up shrouding the valve too much to really take full advantage of them. If you want I have the number to a local machine shop that could probably tell you weather or not you will have any issues with bore clearance....they're over in Streamwood and have a really good rep for high HP engines...PM me if you want the number....they're not sponsors...

joelster

2.05/1.57's will clear a 4.00" bore just fine. The camshaft has a LOT more to do with ptv clearance than the valve size. When you smack a valve it is the exhaust valve from the piston chasing it up on the exhaust stroke.

Wicked94Z

iTrader: (26)

am_muscl

iTrader: (19)

I called a local machine shop and they said it should be ok because I found out they are a stock casting ported head. They have been approved by Port Pro's and they have been fully checked.

Just for sense of security I am gonna have them gone through and checked by a local shop as soon as I get them.

I appreciate everyone's input it has really been helpful and I will make sure to let everyone know how it runs once they are done, I'm trying to get this all done by the shootout so I have something to go down the track.

The car is by no means a "show car" but I will blow my **** up to get the car in GMHTP