roller tip rockers

Has anyone had any experience with roller tip rockers? I am wanting to boost my existing cam a tad, and I was thinking of going 1.5 intake, 1.6 exhaust. I have to replace the rockers now. When they rebuilt the engine, I think they might not have matched the order replacing the original stock rockers. Even if they did, they had come from an high mileage engine with a worn lobe.
I was thinking of replacing the pushrods, and rockers. The cam and lifters have 12,000 miles on it.
I am just wondering if it is actually worth it. It is for my daily driver project van.

The biggest advantage to roller tip rockers is reduced valve guide wear. If you are replacing them anyway, the roller ones aren't a big investment. Pushrods too is always a good idea.

I'm putting a set of Comps stamped roller tip rockers in my truck. Give me a few weeks and I'll tell you how I like them.

I appreciate the feedback. I am at the R&D part of the fix. I am so tired of reading articles in magazines, trying them out, only to find there was something off and it didn't work out real well.
The stock rockers have worked for engines real well for a long time. I see the new developments, and I wonder how long they last.

I think you're better off buying a dual pattern cam than buying longer rockers for the exhaust.

Well I have yet to start my rebuilt SBC 350 but I have a very mild cam and I read about the 1.6 rockers on the exhaust in the site called Ryan's Dyno runs. I have so far kept the 1.6 rockers on both intake and exhaust but I may later put 1.5 roller tips on the intake and keep the 1.6 roller tips on the exhaust. I am planning to turn the engine over by hand and watch the pushrods in the head guides. I have the lowly 882 SBC heads from a '76 Corvette which was a very detuned model but I had the exhaust ports smoothed out by a professional and those heads look like they are pretty good for low rpm torque which I will need for my OD 4th gear. Anyway what you might want to know is that these heads have oval guide holes for the pushrods and the question is whether with the higher lift the push rod rubs against the side of the hole. Some folks on this Forum say that can be a problem which requires taking the heads off and grinding the bottoms of the pushrod holes slightly. I am hoping not to have to do this and so I will just inspect the push rod motion and see if there is any contact with the edge of the hole. Point two is that even if I see interference with the pushrods I will switch to all 1.5 roller tipped rockers because the reduction in friction is supposed to lead to cooler oil temperatures since the stock rockers really rub across the valve tips. A third point is that maybe the 1.5 roller tipped rockers are still slightly better for lift than the stock lifters because measurements on the stock lifters show that they often do not produce the full 1.5 ratio, so a compromise is to use the 1.5 roller-tipped rockers for slightly more lift and cooler oil, but I will try all 1.6 first.

Don Shillady
Retired Scientist/teen rodder

I would love to hear what you find. My head is nothing special. It came off a junkyard 350, is a two bolt main, and the rebuilder told me it had 305 heads on it. I am beginning to think he fibbed and just hit me for more cash.
I have basically stock heads. I have heard from a variety of people, the 1.6 will fit, won't fit, will fit, will rub, won't rub.
The only thing I did to my heads was to run drag line cable with lapping compound through the cast iron headers into the exhaust ports to the valve guide.
She has plenty of guts right now, and gets great fuel mileage. I went really tall rear gears for turnpike cruising so I am building for torque. I get 18-22mpg on the highway now. Not too bad for my project van. Top end is probably going to be about 2200rpm.
If roller tip rockers are true to 1.5, then that might be the trick. I really want just turn key reliability and feel power.

SUGGEST YOU SPEND COUPLE EXTRA BUCKS AND BUY A
SET OF FULL ROLLER ROCKERS...THE ONES WITH BEARINGS AT THE FULCRUM...MUCH BETTER, LESS DRAG ETC ETC

The reason I was reluctant to go full roller rockers, I do not want to pull my heads to open up for the pushrods. If I went full rockers, I would go with 1.5 for intake, 1.6 for exhaust.
If they fit, I would definately go roller rockers.

Another question. I hope Techinspector picks this one up, is it better to go roller stock, for torque and the quest for mileage, or is it better to go with a mix, 1.5s and 1.6?
So the cam is a good choice, which ratio rockers might work best?

In my quest for milage and torque, I'm going with a Comp XE256H cam. It has a dual pattern so is much like using a 1.5 and 1.6 rocker. For best milage and torque, the fastest off the seat lift rates are desirable. The 1.6 rocker will increase the lift rate off of the seat. The next step is to use a roller cam (roller cams have very high off the seat lift rates), but that is costly.

Well, here is the rub. Do the 1.6 rockers fit on the heads, or do I have to pull the heads and open up the pushrod channels? I am pretty sure I will have to go tall covers, but I have plenty of room. I also like the look.
Are those things a bolt on, or a machine on?

Quote:

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Originally posted by docone31
Do the 1.6 rockers fit on the heads, or do I have to pull the heads and open up the pushrod channels? I am pretty sure I will have to go tall covers, but I have plenty of room. I also like the look.
Are those things a bolt on, or a machine on?

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I put 1.6 true rollers on both intake and exhaust in my 487X heads. I did no machine work, but I did run the taller covers. I am almost positive a stock cover would not work, but a mid-size aftermarket cover might. I went with the talls just for principle.

for full roller or partials the ratio is still the same....In either case in 1.6 ratios you will have to elongate the bottom of the pushrod hole

Jeg's and Summit both sell a tool designed for the job....

You Do Not need to open the hole for full or partial rockers unless you intend to install screw in studs with guide plates too...

For cams upto .450 lift and "normal" rpm use the stock studs will be fine...more than that either way I would recommend the screw in studs.........Doc

dr-bowtie, I am glad to hear you comment on this since I recall you first alerted me to the potential problem of pushrod rubbing in the stock holes, but your comments here are confusing to me. Specifically I have the lowly 883 heads on a 350 and the cheaper type of roller tip rockers from Speedway. I have both 1.5 and 1.6 ratio rockers and I would like to run the 1.5s on intake and 1.6s on the exhaust without elongating the hoiles and using stock rocker studs. I have 1.6 ratio rockers on all the valves now with standard height covers and rotating by hand I can hear no contact with the covers. In your post above you say there is no need to open up the hole except if you use screw in studs and guide plates with lift higher than 0.450. From what you say I should be able to use the 1.5/1.6 combination with no change to the heads?

Don Shillady
Retired Scientist/teen rodder

Don, with the short cam you're running, don't worry about it.

Thanks Tech1, good to hear from you! Yes, in my usual nit-picking way I hope to get cooler running, short lift on intake for economy and slightly more torque with the 1.6 ratios on the exhaust. One question, though. Since ultimately the energy comes from the fuel-air mixture, I guess the reason the 1.6 ratio on the exhaust valves gives more torque is due to better cleanout of the exhaust gases from the previous combustion allowing more fresh charge on the intakes???

Don Shillady
Retired Scientist/teen rodder

Yeah Don, most all motors flow better on the intake side than they do on the exhaust side up to a certain point in valve lift. That's why you will often see "dual pattern" designs being used. The grinder will put more duration and lift on the exhaust lobes than on the intakes to try to balance the flow while maintaining a short intake closing point for good low-rpm performance. On a SBC with stock-type heads, a difference of 8-12 degrees of duration with a corresponding increase in lift seems to work well.