PW3 Settings

Hi

My friend is building my race engine with the PW3 cam & we cant find the set up details. We have missed the people to ask today ie Mick Hemmings & Norman White. So any set up detail appreciated.
Thanks
all the best Chris

http://www.nortonownersclub.org/technic ... etail.html
http://atlanticgreen.com/camsurvey.htm

Thanks Lab
I had found these details. I lfound Johns (Seeley 920) 145 off the valve collet.
Dommie racer thank you sheer brilliance.
Timing now done.
Thankyou once again. Saved my weekend.
all the best Chris

Hi Chris,

I hope you meant 145thou at the pushrod/camfollower!!!

Hi John
Probably!
I was just a bit miffed that we would loose the weekend cos we couldnt find the set up details. Typical started after the shops shut Saturday & I knew you were off to enjoy your Christmas dinner! (cant believe how many people I did not know)
Chris

hehe, "enjoy the Xmas dinner"....the food was to the usual standard....we went to Burger King on the way just to be on the safe side

Some questions for you PW3 users. Have been 'umming and aahing' over the fitment of this cam for quite a while now and knowing my std. RGM cam, although virtually unworn after 22,000 miles is 0.014" short on lift and has to be advanced 5deg to get close to inlet specs (still way out on exhaust), I'm going for it. Engine is stripped and it looks like I have loads of clearance with std cam so may not have to do much or anything with case and tappet barrel clearancing.
The questions are to do with valve spring insulators. My original Fred Barlow cam (supposedly a 2S and measured close to 2S lift with std timing) had the inlet insulators removed. Now, since the PW3 has a little less inlet lift than my old '2S' , but more on exhaust what is the general consensus? delete the insulators or fit them and measure for coil bind clearance. I guess the latter is the sensible option, but was wondering? I can see coilbind could be difficult to measure (never done it) so an angled piece of 50-60 thou steel is needed?
On timing which was the original thread, is there a checking figure (other than the 0.145" TDC spec) for measuring lift and opening/closing at the tappets? Like the std 0.013" figure?
I'll likely be buying from and talking to Mick H but any experience out there would be helpful.
Thanks gents.

hi Keith, if you ask me I will tell you to put the insulating washer back on, then check for coil bind , just done it few weeks ago on a friend's engine and it's quite easy with a pry bar without using any brutal way or damage ,we had fit a "real" 2S (say real cause the previous one we try to time was out of specs on the degree wheel, so I gave a shout to my mate dan Parker in UK who send me a good one ....another story!), and following a mix of Dunstall and jim Scmidt books advise we finish with two insulating under some springs, to have the proper tolerances, and yes we play with timing wheel to advance it by 5°to arrive a bit close to the right timing specs , cause I was not addict of the vernier after reading some awfull stories in that forum...my two cents.the frog

Hi Keith,

The valve opening/closing figures are on the screenshot from Mick Hemmings details IO 50 BTDC, IC 82 ABDC, EO 84 BBDC, EC 48 ATDC.

A handy way of checking your coilbound free play is to turn the engine over until a valve is fully open, then tighten the tappet/valve adjuster. One full turn if I remember is 40thou, so 1 1/2 turns should be 60 thou, any less and you will need to remove the insulating washer, or thin it down to obtain enough clearance. Any more, and you can put a shim under the bottom spring cup, although if it's up to 80 thou free play I wouldn't worry too much about it unless you're going to be revving the nuts off it!

Keith1069 said:

Some questions for you PW3 users. Have been 'umming and aahing' over the fitment of this cam for quite a while now and knowing my std. RGM cam, although virtually unworn after 22,000 miles is 0.014" short on lift and has to be advanced 5deg to get close to inlet specs (still way out on exhaust), I'm going for it. Engine is stripped and it looks like I have loads of clearance with std cam so may not have to do much or anything with case and tappet barrel clearancing.
The questions are to do with valve spring insulators. My original Fred Barlow cam (supposedly a 2S and measured close to 2S lift with std timing) had the inlet insulators removed. Now, since the PW3 has a little less inlet lift than my old '2S' , but more on exhaust what is the general consensus? delete the insulators or fit them and measure for coil bind clearance. I guess the latter is the sensible option, but was wondering? I can see coilbind could be difficult to measure (never done it) so an angled piece of 50-60 thou steel is needed?
On timing which was the original thread, is there a checking figure (other than the 0.145" TDC spec) for measuring lift and opening/closing at the tappets? Like the std 0.013" figure?
I'll likely be buying from and talking to Mick H but any experience out there would be helpful.
Thanks gents.

Click to expand...

Keith, coil cind clearance is one thing, another even important matter is springpressure. I've seen cams distroyed by far too much pressure and too little pressure causes floating valves at high revs. You should aim for 200 ft.lb at full lift and 100 ft.lb at rest. I NEVER build a head without meassuring valvespring pressure because springkits of various manufacturers can differ a lot :!:

Thanks for the replies. Mick just says set it up as standard so I figure if I can achieve the 0.145" at TDC then as these cams are reputedly so accurate the timing should be right. I was looking for the checking figure at opening/closing as most cam makers specify a lift and for a std cam it's 0.013" tappet lift at open/close point. Using the adjuster to crank down the spring, that's a brilliant idea, never though of that!
Yes I'm aware of the dangers of 'heavy' valve springs but I don't have a fixture to measure that. I am using std springs (RGM) which have done 22k miles and they do take quite a bit more force to compress than the originals (Fred Barlow from about 1996). The LH exh valve in particular has a nasty wear pattern and has in 4000 miles wrecked a new adjuster and totally mashed the valve stem. It has a very similar contact pattern to the RH which is fine.
Chris, Have just returned from I think it was your 'favourite' head specialist Len at CHS to pick up a replacement!! Could be a rogue valve of course with poor hardening!!
I'll do some comparative tests with the old springs which never had trouble at my 6500 rev limit (2S cam), certainly never experienced any valve float so maybe these will go back in. Will use my big old bench vice and a spring balance to see what differences there are at 32mm specced closed length and 22mm open.
Cheers.

Hi keith

Going for it I see! We are using shim steel under the valve springs as per Johns advice. The big valves, in the Hemmings reangled head, have altered a lot of things. The first PW3 cam we had from Norman white a few years ago was not spot on. This one set up as per a standard cam is spot on.
As to Cylinder head companys John loves them!!!!
I have only had one top end done & that was by Fred Swift. It is superb but is on my triple not my Norton.
all the best Chris

I'll do some comparative tests with the old springs which never had trouble at my 6500 rev limit (2S cam), certainly never experienced any valve float so maybe these will go back in. Will use my big old bench vice and a spring balance to see what differences there are at 32mm specced closed length and 22mm open.

Click to expand...

Well, of course I couldn't get an absolute measurement this way but the old springs are quite different from RGM's which have been in this engine since 2003. Firstly they are wound the opposite way (although still opposite to each other as should be), the coil section for outer/inner is 0.145/0.100 v RGM 0.155/0.120, length is a little longer by 0.07/0.07 and diameter is less by 0.02/0.043. In addition the RGM inners have 5 coils instead of 6 and are far stronger.
On my vice which has a 1" dia x 1/4" pitch thread it takes 2 and 5ftlbs to compress the combined RGM spring set to 1.26 and 0.90". The old springs take 1.75 and 3.75ftlbs. RGM say they are suitable and can't explain the differences and it may be that they are correct and the old Fred Barlow installed parts are not std. Can anyone confirm - Std inner and outer coil wire guage, direction of wind for outers, no. of turns for inner coil. Here are pics, RGM on right......any clues? appreciate any advice and thanks. Keith