Board Logo

Ratio rockers in a 1641
Split nut - February 16th, 2004 at 08:38 PM

Can anyone tell me if it's worth putting my 1.4:1 ratio rockers in my 1641 dual port in my 62 bus. Also, if I do try it, do I have to make any other modifications to fit them, will they fit in the original rocker covers???

Thanks.


Bizarre - February 16th, 2004 at 08:44 PM

Some say yes
Some say no

:D

Cant say - i have not done it. But i think i sit on the yes side.

Have you seen the price of a set???
Not cheap.

Then you need to cut to length your push rods.

Same money would buy a set of Webers

Barry


Split nut - February 16th, 2004 at 08:49 PM

Thanks Barry. I've got a set sitting in the shed. If I do try them out, how do I determine the new length of the pushrods?

Ross.


Bizarre - February 16th, 2004 at 09:04 PM

from John Conolly @ aircooled.net

http://www.aircooled.net/gnrlsite/resource/articles/t1hpeng.htm 

"Proper length ensures that at "half lift" the rocker arm is pushing the valve straight in. If "rocker geometry" is off, the valve will be pushed up or down, and this results in valve guide wear. Get it right! This is one of the most intricate parts of engine building. Cutting and assembling your pushrods is a real pain (I hate it). For assembly purposes, you need an adjustable pushrod to have any hope of achieving optimal rocker geometry. You use the adjustable pushrod to cut your chromoly pushrods to the desired length then tap the ends in using a hammer and two old lifters (to keep from screwing up the ends of the pushrods)."

Have a read.

What cam is in there now??

A stock one??


Craig Torrens - February 16th, 2004 at 09:10 PM

mmm I won't even comment Barry :D:D


Split nut - February 16th, 2004 at 09:21 PM

Thanks guys. It seems there is a lot more to consider than just bolting them on and taking the bus for a burn. I think I will leave it the way it is and enjoy reliability.


Bizarre - February 16th, 2004 at 09:24 PM

heh heh heh

The "other" side of the fence just turned up!

C'mon neighbour - give the other side!

I told Ross there was 2 sides.

TTFN


Craig Torrens - February 16th, 2004 at 09:33 PM

the fence is to high to talk over Barry :D...................keep it to one side, more simple then.


pete wood - February 17th, 2004 at 11:06 AM

I had a 1641 in a beetle and my mechanic, Hans Klaack said ratio rockers are dead set the way to go on a dead standard engine.
He used them on a 1600 in an offroad buggy and it won the class and many events outright because of reliability. In fact, it didn't break down all season. And this was with a driver who thrashed the car to the point of not lifting off the throttle while airborn. That's right, free-revving on open throttle.:o
Just get them properly installed with moly pushrods and your motor will be fine.:thumb


Craig Torrens - February 17th, 2004 at 08:50 PM

1.25's will just bolt on, and will give you the same benefits as 1.4's.

Depends on Cam design as well as Valve size.


Split nut - February 17th, 2004 at 09:22 PM

Problem is that I bought the engine a couple of years ago and have no idea what cam or valve sizes it has. The heads were new, I'm assuming they had standard valves in them.

Generally it runs fairly smooth, so I'm working on the assumption that it's a standard cam too.

I run a standard 34 pict carb with Kadron extractors and I thought that the ratio rockers may give that little more punch.

Still undecided, am I messing with reliability or will it still be as reliable. Some say yes, some say no. I am more concerned about reliability than power for this bus.


Craig Torrens - February 17th, 2004 at 09:31 PM

As long as they are good quality rockers then your reliabilty will not be effected. 1.4's will put additional strain on your pushrods, so the general advice given would be to change to chrome moly pushrods.

I personally wouldn't bother, sell the 1.4's or save them for the next motor :D

[Edited on 17-2-2004 by Craig Torrens]


Split nut - February 17th, 2004 at 09:52 PM

Thanks for the advice guys. For now I might leave them for the hot motor to go in the dual cab down the track.