Rocker Arms

Moderators: Sluggo, Amskeptic

Post Reply
User avatar
ruckman101
Lord God King Bwana
Location: Up next to a volcano.
Contact:
Status: Offline

Rocker Arms

Post by ruckman101 » Sat May 29, 2010 7:07 pm

Stock or 1.25 to one? I'd appreciate folks thoughts on this. Engine is stock, otherwise, 1600 dp. It's going to go into the Ghia, replacing the 1600 sp currently in there.


thanks,
neal
The slipper has no teeth.

User avatar
Hippie
IAC Addict!
Location: 41º 35' 27" N, 93º 37' 15" W
Status: Offline

Post by Hippie » Sun May 30, 2010 5:42 am

Pros and cons:
Stock rockers are scarce, all NOS AFAIK. 1.25:1 are easy to find.

1.25 adds some stress to the valve train. My guess is push rods are harder to keep straight and cam wear increased slightly.

Now let someone with hard experience really answer your question. :pirate:

User avatar
Bookwus
IAC Addict!
Location: City of Roses
Status: Offline

Post by Bookwus » Sun May 30, 2010 8:11 am

Hiya Neal,

Being a stock kinda guy, I go with stock naturally. Heck, they were good enough to get the engine through all the miles it's already logged. And you (presumably) already have a set of 'em sitting on your workbench.

By the by, CK has a little routine for clening these things up. I've used it on my rebuilds and it is great.
I have cancer.

It does not have me.

User avatar
ruckman101
Lord God King Bwana
Location: Up next to a volcano.
Contact:
Status: Offline

Post by ruckman101 » Sun May 30, 2010 3:31 pm

I just have to find the originals, but I don't recall seeing them offhand. But if I have to buy new assemblies....

The 1.25 to one ratio allows more air/fuel because the valve opens deeper, and thus longer. Would it be pointless with a stock exhaust?

Curious is all, hoping I can find the stock ones on my shelves of bits and pieces.



neal
The slipper has no teeth.

vdubyah73
IAC Addict!
Status: Offline

Post by vdubyah73 » Sun May 30, 2010 4:14 pm

doesn't stay open longer. still follows same cam profile just snaps open farther and slams shut faster because it has to travel more distance in same time. study valve train geometry and pushrod length carefully. If you get it wrong your valve guides will be junk in short order. You will be laying smoke screens while making turns quick enough to move oil around in the v/c's. A quick turn, while off the throttle, creates high vacuum and oil gets sucked rite through the worn guides. Ask me how I know. The samba, shop talk forums, and cal look all have good info. Every engine is different, I thought I could use a set of shortened push rods from a stock 1600 using 1:25 rockers in an engine with a 110 cam, uh uh wrong. engine was smoking within 5000 miles. So study the valve train geometry and push rod shortening procedure carefully. shortening them is fairly easy. you buy the pushrods that are ready to cut to length and the adjustable pusrod to calculate length. I cut the rods with a small plumbers tubing cutter, deburred the inside of the cut end with the tang of a hand file, and drove the new end into the pushrod with a pair of lifters and a hammer.
1/20/2013 end of an error
never owned a gun. have fired a few.

vdubyah73
IAC Addict!
Status: Offline

Post by vdubyah73 » Sun May 30, 2010 4:22 pm

Forgot to mention valve spring issues. Have to make sure the springs can compress the extra distance without binding, and don't wind the engine higher with tired old springs, they may not have the strength to follow the cam with the extra lift. I got away with it in the mostly stock 1600, dual Kadrons and an aftermarket extractor exhaust.
1/20/2013 end of an error
never owned a gun. have fired a few.

User avatar
ruckman101
Lord God King Bwana
Location: Up next to a volcano.
Contact:
Status: Offline

Post by ruckman101 » Sun May 30, 2010 4:38 pm

Oh oh, sounds like there is more to take into consideration than merely slapping on a rocker arm assembly with higher ration rocker arms. If that's the case, I'm not ready to go there yet.


neal
The slipper has no teeth.

Post Reply