jtranger

I would like to install a set of roller tip rockers on my stock '65 327/365. Does anyone know where I can get stock roller tip rockers that will work with the stock valve train components and valve cover clearance. I heard an additional 20 Horsepower gain and less wear would be the benefits of the roller tips. Please chime in! Thanks

Plasticman

Yes, less wear (at the valve stems and guides), but 20 HP? I doubt it!

Use the Comp Cams 1412-16 Magnum roller tipped rockers (for C1/C2/C3 SBC engines) available at Summit Racing, Jegs, etc.

Note that they recommend guide plates and new pushrods.

I would stay away from the stamped steel Crane, Summit (house), etc. versions.

Plasticman

jtranger

John, Whats wrong with the stamped steel ones from summit? They look like they are stock and would bolt up without modification.

Kensmith

Make sure you have the correct length hardened pushrod as some roller tip rockers will require .001 longer rod.

Hitch

The Comp Cams Magnum and Pro Magnum's work but both require guide plates and hardened pushrods. Dave

Plasticman

Don't think .001" is going to make much difference!

The Comp Magnum roller tip rockers use standard length pushrods, but as mention before, they do require guide plates, and therefore hardened pushrods.

Plasticman

Plasticman

The Comp Magnums are known for their precise 1.52 ratio, whereas the stamped rockers (including the original Chev. rockers) can vary over a wide range. Have seen anywhere from 1.37 to 1.47.

Besides, the stamped area where the roller tip is pinned just "looks" too weak and would be a poor usage for high lift cams or for longivity. The Comp Cams versions are known for their high strength and life.

Plasticman

66BlkBB

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I put these in my 427 a long time ago. Did not use guide plates but did use new push rods. No problems so far. I went to Jegs site. Didn't see where they recommended guide plate. I may have missed that recommendation. I also put a set in my 327 that is in my 32. Didn't use guide plates there either. Still runs just fine. I am not running high lift cams in either engine so that may make a difference also.

No 20 HP gain though as far as I can tell. It is just easier on the valve train.

Steve

Hitch

The big blocks it does not specify to use guide plates but for the SB guys we need to run them. This is lifted straight from the CompCams website..

http://compcams.com/Technical/Instru.../Files/250.pdf

knight37128

Big blocks have guide plates from the factory.

Plasticman

Note that in the past, Comp Cams did not have that recommendation for SBC engines. Don't know when they added it, but I am sure they had a reason (to sell guide plates and hardened pushrods).

I have used them on several engines without those 2 items with no ill affects (with the 1.52 ratio roller tipped rockers). But take your chances if you choose to try it. The higher 1.6 ratio rockers will need the guide plates no matter what, since the cast-in-head pushrod holes must be opened up.

Plasticman

Joys

I am using the Comp Magnum rockers in my 327" L79 with exellent results! I too was a little worried about the requirement for guide plates and hardened pushrods so I called the tech dept. at manufacturer and asked them about this. They asked me what year my motor was, when I told them 1966 they told me to forget this requirement due to the fact these early cylinder heads already have the narrow pushrod holes and subsequently does not need any guideplates. I have run this setup now for about four months all rpm's with no worries! Fits good under my alu. finned covers.

Plasticman

Joys,

Thanks for the confirmation!

Plasticman

jtranger

Thanks for the clarification Erik!

ghostrider20

There are 2 part numbers, those with the use of guide plates, and those without.

If you can wait a month or so, I will send you mine for $50.00 and a new set of pushrods to go with them.

Mark

wmf62

the story of my life, i buy some and someone is practically giving some away.....
Bill

jtranger

Mark, I will take you up on the roller rocker offer! Larry 714-647-5543 or jtranger@pacbell.net.

Tom454

I did a test on the roller tip rockers using a cam-corder.

I reference marked the rollers and the roller retainer lip and ran the engine with the valve covers off. I recorded a few minutes of run time using a timing light to strobe the rocker.

I could not see any movement of the rollers. I.E.- they did not roll across the valve tip... they scraped just like a standard stamped steel rocker.

The test was done at idle because at higher rpm my camera did not record enough frames per second... it just blurred.

I have them in my truck... and I did the valve job on it myself, installing bronze valve guide liners and honing each guide to match the target valve. Time will tell if they really do prolong valve guide life.

2 cents.

toddalin

I use the Comp Cams 1.52:1 roller tip rockers without guide plates with excellent results and no valve cover clearance issues.

My set-up:
331 CI, pump-friendly 9.5:1 CR
K&N 14"x4" air filter, Corvette drop base and lid
Holley 600 dp, choke horn milled, polished
1/2" Aluminum open spacer port matched to manifold, exterior polished
Edelbrock Performer RPM, port matched, exterior polished with all extraneous castings and lettering removed
Homemade lifter valley splash shield to keep hot oil off manifold bottom
Camel hump 1.94/1.50 heads hogged out to 2.02/1.60, pocket ported, port matched, pump-friendly hardened seats, 3-angle valve job
Comp Cams 1.52:1 roller-tip rockers
Crane Cam Vintage Muscle 327/350 hp cam, 222 degrees @ 0.05, 0.447" lift (with 1.50 rockers)
Doug Thorley headers, dechromed and ceramic-coated
2.5" mandral-bent exhaust (including tips), 2" cross-over just before rear axle
DynoMax stainless Ultra Flow mufflers
Mallory Hyfire IV CD ignition box triggered off Accel points
Mallory high voltage chrome coil
Mallory spiral-wound coil wire
Mallory solid copper plug wires, ends soldered to wires
Champion plugs
37 degrees total ignition advance (now 34 degrees per Lars tune-up)
Carter high volume fuel pump
Melling high volume oil pump
Open breathers
Polished aluminum high flow water pump
Flex fan with polished aluminum spacer
Polished aluminum one-wire 100 amp alternator
Muncie M-20 CR 4-speed (now Keisler TKO600 5-Speed)
Hurst shifter (Now Keisler With Hurst Tower)
3.70:1 positraction
225/60/15 Firestone Firehawk SZ50s on 7”-wide Western 30-spoke Turbine Wheels

At the time of the dyno pull engine had never been professionally tuned up. Car did 293 ft-lb and 293 hp @ 5,500 rpm on the chassis dyno. Engine pulls to 6,200 rpm and does over 200 ft-lb from 1,900 rpm. This was prior to some clean-up work around the junction of the carburetor and base of the air cleaner that smooths the flow through this area and a Lars tune-up and should be good for a few ponies. Car has run 107 mph in the high 13's (old, bad tires) at the quarter. Car is extremely streetable and could probably even run 87 octane if it had to. (I can't get the engine to ping no matter how far I advance the ignition.)

The secret to power is in the attention to details!

jim lockwood

John Lingenfelter, in his book "On Modifying Small-Block Chevy Engines" agrees completely with your findings. It's probably not a good idea to quote a passage from the book without permission, so I won't. However, interested readers should refer to the lower right corner of page 113.

There he says explicitly that the roller tip, once valve spring force is applied, can no longer turn and that it merely slides on the top of the valve stem.

Roller tipped rockers seem to be less of a technical breakthrough and more of a marketing breakthrough.

Jim