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Well, the short answer is no, not really. The lift generated is way too much and you will get coil bind and shatter the springs. Also, the whole valve geometry will be completely wrong.
 

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hey.

im interested in this as well but when i rebuild my engine (when funds allow) uwant to get 1:5.1 rockers. what do you need to do to allow this?

cheers :hangloose
 

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1:4 ratio rockers will work on a standard 1600. My Father is doing just that with a set of Autocrafts. He is also using stock springs, as he doesn't rev his bus through the roof, but he is using chro-moly pushrods and lash caps on his valve stems. Must have had them fitted for three or four years now, with no problems at all. If there is any doubt about the springs binding, before firing up, rotate the engine by hand to maximum valve lift, and make sure that a ten thou feeler blade WILL fit between the spring coils, and you'll be OK.
 

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bugger 61 said:
1:4 ratio rockers will work on a standard 1600. My Father is doing just that with a set of Autocrafts. He is also using stock springs, as he doesn't rev his bus through the roof, but he is using chro-moly pushrods and lash caps on his valve stems. Must have had them fitted for three or four years now, with no problems at all. If there is any doubt about the springs binding, before firing up, rotate the engine by hand to maximum valve lift, and make sure that a ten thou feeler blade WILL fit between the spring coils, and you'll be OK.
ok...the question was referring to a stock 1600, wheras the motor you are talking about is not a stock 1600 as you have replaced the pushrods, presumably cut them to length to set up valve geometry? Did you need rocker shims? Without doing the maths, my immediate thoughts would be valve to piston clearanace as well. Have you/your Dad looked at this when building the motor...I know you say it has been running for years...but I'm curious about it.
Hope you don't think I'm being too nosey... :)
 

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Nothing nosey about asking questions, Bud! I wouldn't attempt to answer questions if I were not also willing to justify my answers. I had just fitted 1.25:1 rockers to my 1200cc and Pater had to go one better. Either he or I would have gone over the net's recieved wisdom on the subject of 1.4's. We had lengthy conversations at Beauleiu that year, as I recall, about the merits of such things, geometry and such, but I don't recall what he did about such issues- he has lathes and mills as have, I so he would have sorted such issues himself. What I can say is that he would look at an addition like ratio rockers as an addition to a SYSTEM, and therefore if rocker shims were needed, he would just have made them, and I may not have heard about them. Going back to the system thing, I'm pretty sure it was I that said "lash caps" but the set of rockers came with chro-mo push rods, and if these were too long, I'm sure they wouldn't have been fitted without modification.
 

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64J said:
how do you work out the length of the push rods needed if using 1.4 rockers? tis on a ad case so 69mm crank?
You buy a set of aftermarket (cut to length) pushrods which have one end disassembled.

Using a dial gauge, and rotating the crank by hand, measure the total amount of lift on one cam lobe, then rotate the engine so that that cam lobe is exactly at half lift.

Make an adjustable length pushrod by cutting an old stock one in half, and tapping and threading it. Fit this pushrod in the position where the cam lobe is at half lift, fit your rocker assemblies and torque them down. Adjust the length of your adjustable pushrod (watch it dosen't bend when you do this) so that the centre of the rocker arm pad is exactly in line with the centre of the valve stem (in the horizontal plane), but the rocker needs to be slightly off to one side on the vertical plane to rotate the valve in use.

Then dissasemble and measure exactly the length of your adjustable pushrod, and cut all your adjustable rods to be exactly that length, preferably on a lathe but you can use a drill press and a hacksaw blade if you're stuck.

Use a pair of old cam followers to hammer the seperate end into the new pushrods.

Dave.
 

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Wot he said! :D

In addition, if you are using a dual spring head, then use just the outer spring when setting up as it's easier to rotate!
 

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Hey Whippy, how are you? It's been a while since we last met! I do tend to get a bit nostalgic at this time of year as we approach bonfire night...remember the crazy pyrotechnic parties !!! :D :eek:
 

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Sure do Rob -

But I've still got all my fingers ! (more by luck than judgement though)

You sure know how to throw a good bonfire party - You don't forget exploding pumpkins easily !

Cheers - Whippy.
 

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I'm the chap who is running them :D as my son said I used the chromoly pushrods because they came with the rockers; all I did was to shim under the rocker stands to get the correct geometry, nothing else. They made the van pretty nippy! :D
 

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deejay451 said:
Sorry there was something else. I definitely fitted lash caps!
No problem, set the valve geometry as above with the hardware fitted as you are going to run it, any changes from stock valve train you should check and adjust the valve train geometry to get the best from your engine.

Also, when working out the correct pushrod length, set the valve adjustment screw roughly in mid-position first, and shim the rocker shaft from the head as required. (using swivel feet adjusters and / or lash caps may mean the rocker shaft needs shimming away from the head.)

Dave.
 
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