Topic: Rocker Questions

[bambuhiphop]

Happy New Year All

Was hoping to get some advice on some rockers. Goal is to get a set hardwelded for the new engine. I have two sets. One set is off a 75' and the other a 78'. 75' set are all very clean. Very light oil film on them and no pits. The 78' set is solid but 1 has a small pit and the oil on them is a little thicker and slightly burned.

Also, I am see degree(?) numbers on each of them. Not really sure if that effects which I should use. Set 1 have 83,85, & 86 markers and set 2 has 76 & 77.

Which set should I send out?

[BomberMann650]

Those are likely casting numbers.

Are you getting a hardweld cam to go with the rockers?

I'd Send the worn and pitted set for hardwelding.  Keep the nice ones for stock rebuilds.

[bwaller]

+1

[bambuhiphop]

Those are likely casting numbers.

Are you getting a hardweld cam to go with the rockers?

I'd Send the worn and pitted set for hardwelding.  Keep the nice ones for stock rebuilds.

I have a billet yoshi cambin there already.

[BomberMann650]

Yoshi?! Sweet!   

[bambuhiphop]

Yoshi?! Sweet!   

Indeed. Picked it up off a fellow member, Greggo, few years ago. And actually Bill/BentOn Racing orginally purchased it back in 1985 on clearance. I found that out because he posted photos in a thread from 2009 and I recognized the box. Here is that thread. His mention of it is post 32.

http://forums.sohc4.net/index.php/topic,55272.msg598834.html#msg598834

It is a Isle of Man TT B grind. Never been used. Here is a recent pic of it in my engine I am building.

http://forums.sohc4.net/index.php/topic,86158.msg1867400.html#msg1867400

[BomberMann650]

That's one hot lookin 550!  How does the yoshi iom cam compare to the stock? 

[bambuhiphop]

This is the info I have scrapped together on the Yoshi specs...

Int opens 27°BTDC
Int closes 57°ABDC lift 9.00mm
Exh opens 56°BBDC
Exh closes 27°ATDC lift 8.55mm

This is what I have found on a stock cam...

1.36 exh.       lobe              1.38 in.
1.110           base circle       1.110
0.252              lift              0.272

intake duration 240 ex 245.Intake lift .300 ex .280

[calj737]

I would confirm with Mike Rieck that the Yoshi cam is compatible with hard weld rockers. It is possible that the original cam is  a native grind, and not resurfaced (I haven't read Bll's linked thread).

[bambuhiphop]

I would confirm with Mike Rieck that the Yoshi cam is compatible with hard weld rockers. It is possible that the original cam is  a native grind, and not resurfaced (I haven't read Bll's linked thread).

Huh, hadn't thought of that in the slightest. I will reach out to Mike.

[bambuhiphop]

I would confirm with Mike Rieck that the Yoshi cam is compatible with hard weld rockers. It is possible that the original cam is  a native grind, and not resurfaced (I haven't read Bll's linked thread).

Cal... I was hitting up the Google cave to see if I can find any info on this but am not. Could you elaborate on a "native grind"? Thanks

[calj737]

Meaning that it wasn't hard welded/resurfaced from a stock blank to create a more aggressive profile. That is what the aftermarket cams are. I just don't know if the original Yoshi cams were that also. 

[bambuhiphop]

Meaning that it wasn't hard welded/resurfaced from a stock blank to create a more aggressive profile. That is what the aftermarket cams are. I just don't know if the original Yoshi cams were that also. 

Ok, so meaning it is a blank itself (native) or hardwelded from another blank (resurfaced). What's the concern if is not resurfaced with hard weld rockers?

[BomberMann650]

Meaning that it wasn't hard welded/resurfaced from a stock blank to create a more aggressive profile. That is what the aftermarket cams are. I just don't know if the original Yoshi cams were that also. 

Ok, so meaning it is a blank itself (native) or hardwelded from another blank (resurfaced). What's the concern if is not resurfaced with hard weld rockers?

Hardweld rockers will eat a stock/native cam alive.  The softer material loses the wear and tear game.

[bambuhiphop]

Meaning that it wasn't hard welded/resurfaced from a stock blank to create a more aggressive profile. That is what the aftermarket cams are. I just don't know if the original Yoshi cams were that also. 

Ok, so meaning it is a blank itself (native) or hardwelded from another blank (resurfaced). What's the concern if is not resurfaced with hard weld rockers?

Hardweld rockers will eat a stock/native cam alive.  The softer material loses the wear and tear game.

Huh. Makes sense. Can/Rocker interactions are still newer concepts for me. So, what are the rocket options available with the assumption the cam is stock/native?

[BomberMann650]

Meaning that it wasn't hard welded/resurfaced from a stock blank to create a more aggressive profile. That is what the aftermarket cams are. I just don't know if the original Yoshi cams were that also. 

Ok, so meaning it is a blank itself (native) or hardwelded from another blank (resurfaced). What's the concern if is not resurfaced with hard weld rockers?

Hardweld rockers will eat a stock/native cam alive.  The softer material loses the wear and tear game.

Huh. Makes sense. Can/Rocker interactions are still newer concepts for me. So, what are the rocket options available with the assumption the cam is stock/native?

Stock/NOS afaik

[calj737]

Yup. Stock. Would ping Bill Benton or Mike Rieck about the cam to determine hard weld or not. They'll know. They know everything

[bambuhiphop]

Yup. Stock. Would ping Bill Benton or Mike Rieck about the cam to determine hard weld or not. They'll know. They know everything

Cool, thanks for the info guys! Already pinged Mike. He'll get back to me in a few days. Always does.

[MRieck]

Yup. Stock. Would ping Bill Benton or Mike Rieck about the cam to determine hard weld or not. They'll know. They know everything

Cool, thanks for the info guys! Already pinged Mike. He'll get back to me in a few days. Always does.

Hardweld will work with iron cams......I have never had a problem and Megacycle says there is no problem. Use a zinc additive (ZDDP is what I use).

[bambuhiphop]

Yup. Stock. Would ping Bill Benton or Mike Rieck about the cam to determine hard weld or not. They'll know. They know everything

Cool, thanks for the info guys! Already pinged Mike. He'll get back to me in a few days. Always does.

Hardweld will work with iron cams......I have never had a problem and Megacycle says there is no problem. Use a zinc additive (ZDDP is what I use).

Thanks Mike