Cam install/roller tip rockers

Carmine

Well Known Member
Supporting Member 6
#1
Hi everyone. I know how to install a cam and lube everything properly, but is in imperative that I start the engine for break in right away or can it wait for warmer weather??
And for pretty much street use, does anyone think the roller tip rockers in the same ratio as originals, add horsepower, are worth the investment?? Just wondering, Carmine.
 

Fathead Racing

Well Known Member
Supporting Member 6
#2
You can wait. Prelube cam with high grade break in lube like Royal Purple, something that won't run off. If it sits you also must prelube with oil pump drive tool until you have oil to both sides of rockers. Roller tip rockers should come in 7.0 or 7.2 ratios. They do help with relieving side load on the valve.
 

La Hot Rods

Well Known Member
Supporting Member 1
#3
As Ray said lube it up good and you will be good.
I am sure GM has stacks of assembled engines setting around. But they may have been run in. :dunno2

My thought on the roller tip rockers is that you would stand a better chance of getting a rocker arm of a known ratio as to a stamped steel rocker arm.
I have used the Comp Cam roller tip and had good luck with them.
 

models916

Well Known Member
Supporting Member 7
#5
Pushrod length is real important on the roller rocker and the roller tip only. Tip should be dead center at mid lift. Some nut adjustment available if you have a hydraulic lifter to in effect change the length of the pushrod. On a solid, you set the gap and go to mid lift and then get the correct pushrod length. On a solid lifter engine, you should probably figure the cost of pushrods also.
 

Carmine

Well Known Member
Supporting Member 6
#6
Thanks models916. I was just exploring some different things. Every once in a while, I get some bright ideas about something and most of the time, they don't turn out so well. There is no doubt I'm doing a cam change, but for now, I think I'll leave the stamped rockers on, Carmine.
 

Carmine

Well Known Member
Supporting Member 6
#8
No matter what rockers you have,make sure your push rod length is correct.
I started taking the motor apart yesterday. Definitely stock rockers and pushrods, which are torqued and not adjusted like Chevy. I didn't have any issues I'm aware of beforehand with them, so I'm thinking they should be fine with the new cam and lifters. I do recall measuring the correct pushrod length on my "W" engines, Carmine.
 

Carmine

Well Known Member
Supporting Member 6
#12
How could your rockers be torqued?
From everything I read and have been told, the rockers and nuts are not adjustable. You tighten and torque the nut to I believe 25 ft. lbs. My mistake and apologies for not explaining better. This thread is about my 400 Pontiac engine. I could get an after market adjustable valve train, but don't want to. Going to have to measure for correct length push rods because of the cam change. If the existing cam was stock, I don't think I would have to do this. Who knows what's in there now. Looking forward to putting the valve covers on and fire it up without oil squirting all over the place. Funny thing, out of all the GM V-8 motors, Chevy has the only adjustable rockers/valves. I wonder if their longevity from 1955 to present, small block engine design, has anything to do with it??
 

Carmine

Well Known Member
Supporting Member 6
#15
Short story. Maybe. Pulled the cam in my Pontiac today and looked at the manufacturer name-Lunati-and part #07702. I remember the 702 and had an instant meltdown. This is the cam I chose to replace what was already there. OMG. All that work, expense and I already have that cam. I felt the blood drain from my face and my knees got weak. I wondered how I could be so wrong about this cam, but I was. I blamed it for my low vacuum and was going to replace it with the same. Yikes. I came in the house and still couldn't believe it. The Lunati Voodoo 262 came so highly recommended, but I already had one in the engine, at least I thought. And it was terrible. So, I did a little research. The Lunati Voodoo 262 that I wanted to install, is part #10510702. My present cam is a Lunati with the last 5 digits 07702. Not the same as 10702. Maybe a part# change?? Nope. The 07702 is a different cam all together. That cam is advertised as good for pro street. 2500-3000 stall converter. Headers. 9.1 CR. 3.73 gears. I have a slight stall converter, but nothing else. No wonder why that motor didn't run right. It was over cammed just as I thought. Night and day between the two. So, I'm starting to feel so much better. I'm going to order that Voodoo cam tonight. It will take a few days to get here and give me some time to clean and paint parts. Then, measure for the correct pushrod length and put it back together. This car is also a factory A/C car and I never tried to get it working. I think it needs some additional vacuum parts, but 99.9% of it is there. What a PITA to remove the compressor, brackets and condenser. I really don't care about using it, so I'm not putting it back together. I'll label and box everything. Let the next owner figure it out, Carmine.
 

Don Jacks

Well Known Member
Supporting Member 2
#17
Yes there's a big difference between those two cams.Now to the good side,the stock valve springs will not work with that cam so check them.Look to see[or post pictures as we can tell] if the heads have been machined for aftermarket springs.The cams that you mentioned will take the same spring.In that case,all you should need is the cam,lifters,and maybe push rods.It'll be less work for you.
 

Carmine

Well Known Member
Supporting Member 6
#18
Thanks guys, I appreciate your replies. I'm going out to the garage later and will take a look at the heads and springs. I will take some pics and post them because I'm not sure what I should be looking for or at re. machining the heads for different springs. If I can ask, what actually happens when a camshaft such as the one I want to install, is not compatible with the existing springs?? Is it a recipe for trouble?? What kind of trouble?? I do know that on several occasions, I ran the engine up to 4800-5000 rpm's and it was solid. No missing or hesitation. Felt like it might go further but I didn't tempt it. Would that be indicative of having the proper springs?? Many thanks, Carmine.
 

Don Jacks

Well Known Member
Supporting Member 2
#19
The stock springs would bind up if used on a cam with that much lift,resulting in bent,broken parts.Yes,that cam should pull to 5,500 plus with the proper springs,but then you're asking for problems with the rods.
 

Carmine

Well Known Member
Supporting Member 6
#20
Just took some pics of the springs. Didn't look for any names/numbers on the top of them, but I can if it's important. The base of the spring seems to be seated deeper into the pocket. It certainly not sitting on or flush with the surface. Not sure if this means it's been cut or not. Thanks for looking.
I know I don't have an interest in 5500 rpm's. I would settle for a solid, no problem 5000 rpm on occasion. Most of my driving would be in the 2500-3000 rpm range, Carmine.
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