Topic: Roller Rocker tips?

[TwoTired]

Would roller rocker tips solve the valve guide wear issues on the 750 F2/3 cylinder heads?

Anyone want to comment on the feasibility?

Thanks,

[MRieck]

I thought Hondaman mentioned something about roller tips with quarter midgets and alcohol.

[hcritz]

Hey TwoTired...
Small block chevy's are really tough on valve guides because of the rocker geometry...the roller setups really here there.
Does anyone make them for these Hondas???
I would guess that you would have to be careful about additional mass of the rocker assembly...

[dusterdude]

that would be a good thing to have if someone out there is making them.

[crazypj]

Nearest thing I could think of would be something similar to the VW Bug / Porsche 'elephant foot' adjusters. Never seen them small enough for a 4 though. They would be heavier than stock adjusters. I wouldnt want to cut some up and weld bits in to make roller type, although I guess its feasable, have to find some miniature needle roller bearings first, but not sure it would do any good when the tappet will still be 'pulling' the valve side to side.
I'll think about it a bit
PJ

[hcritz]

A lot of the newer cars are using roller lifters, rocker pivots and tips...The goal is better milage...quite a bit of friction in the valvetrain.
Most OHC engines now have tiny hydraulic lifter fitted into the tips of the rocker...eliminates valve adjustment...pretty cool, but I'm sure drives up the cost of engines.

[bryanj]

Don't think a roller is feasible due to lack of space, Triumph tried a ball bearing end with a flat on it to contact he stem but don't think it was that successful

[TwoTired]

I kinda hoped MRieck would know where to get these rolller rockers.

hcritz,
The SBC engine is where I got the idea.  Along with the knowledge that Honda borrowed from the Hot Rodders bag of tricks to get more power out of the 750.  Bigger valves and increasing the valve angle to keep the big valve heads from from hitting things in the cylinder.  Roller tipped rockers are used on the SBC to extend valve guide life as well as reduce friction.  The SBC also uses different length arms on the rockers to increase lift as that and higher lift cams place a lot more side loads on the valve stem during the valve stems tip's arc of travel.

Did Honda's valve guide angle change the rocker ratio on the F3?

I wouldnt want to cut some up and weld bits in to make roller type, although I guess its feasable, have to find some miniature needle roller bearings first, but not sure it would do any good when the tappet will still be 'pulling' the valve side to side.

I thought the purpose of the roller tips was eliminate that "pulling".

bryanj,
I admit I hadn't thought of cover clearance.  And, indeed, the SBCs with roller rockers also have taller valve covers.
 Just how much clearance is available under the existing cover?

MRieck,  How tall are those "lash caps" you use on the stem tips?

Thanks for your thoughts,

[hcritz]

I still have a set of the old VW rocker feet...they actually worked pretty well and increased the time between valve adjustments...but the do take up a good bit of room.
Check out some of the hotrod parts...they have some pretty simple roller tips...most are just that...rollers...not actually bearings
Might be feasible to make for the Hondas.

[Big Jay]

The valve end of the rocker is where the adjuster is.

Jay

[MRieck]

I kinda hoped MRieck would know where to get these rolller rockers.

hcritz,
The SBC engine is where I got the idea.  Along with the knowledge that Honda borrowed from the Hot Rodders bag of tricks to get more power out of the 750.  Bigger valves and increasing the valve angle to keep the big valve heads from from hitting things in the cylinder.  Roller tipped rockers are used on the SBC to extend valve guide life as well as reduce friction.  The SBC also uses different length arms on the rockers to increase lift as that and higher lift cams place a lot more side loads on the valve stem during the valve stems tip's arc of travel.

Did Honda's valve guide angle change the rocker ratio on the F3?

I wouldnt want to cut some up and weld bits in to make roller type, although I guess its feasable, have to find some miniature needle roller bearings first, but not sure it would do any good when the tappet will still be 'pulling' the valve side to side.

I thought the purpose of the roller tips was eliminate that "pulling".

bryanj,
I admit I hadn't thought of cover clearance.  And, indeed, the SBCs with roller rockers also have taller valve covers.
 Just how much clearance is available under the existing cover?

MRieck,  How tall are those "lash caps" you use on the stem tips?

Thanks for your thoughts,

.040" sir.

[Sam Green Racing]

I saw a set in a CB77 motor a few years back.
It was claimed to be a Yoshie motor, perhaps he did them.

Sam.

[bill440cars]

         Of course roller rockers have been around (Ford, GM & Chrysler)car engines as a high performance add on item for a very long time. Anything that reduces friction and makes for a smoother operation will help. Of course,as stated, you have to have room to install them and it also has to be something feasible while (hopefully) not costing an arm and a leg. Later on,  Bill