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Gpz1100 unitrac aftermarket cam identification
Posted: Mon Dec 21, 2015 10:45 am
Author: pluto
Hi All,
Finally got a bit of time to look at a unitrac motor I bought in the summer, It has solid front engine mounts so I suspected it may have come out of a special or racer. Lifted the cam cover and all is well, but the non-original cams may confirm my initial thoughts. Does any one recognise these cams? They are fitted on slotted cam sprockets and have made in USA on one side and the markings shown in the pics on the other. When I pop them out to check the rest of the motor, bar marking them so they go back in the same position how do I know the optimum position to refit them in as there are no marks on the slotted cam wheels?
Thanks in advance
Dave
Posted: Mon Dec 21, 2015 11:15 am
Author: sid123
set up dial gauge and degree wheel and measure settings now before dismantling
Posted: Mon Dec 21, 2015 3:01 pm
Author: martinz1000r
Dave, they look like APE adjustable sprockets. If you look carefully there should be some dots that mark positioning. Failing that do as man says and mark everything up carefully before you remove!
Also if you are returning to rubber mounts can we do a deal on the solid engine mounts? I need to get solid mounts sorted for my Moto Martin. Can swap for rubbers assuming I can get them out!
Martin
Posted: Mon Dec 21, 2015 3:56 pm
Author: KWACKERZ1
Dave, I have some CWC big cams i believe they may be Russ Collins Cams.
Posted: Mon Dec 21, 2015 5:22 pm
Author: Ginger Bear
Posted: Mon Dec 21, 2015 8:34 pm
Author: Al
Looks like CWC is the company who casts the blanks. EP14 is part number for the blank (one of many different types of blank)
Is there any marking or stamped numbers on the ends where the 'D' rubbers sit.
If you cant identify them specifically go for around 108 to 110 using the lobe centre method if they prove to be around .410" lift or thereabouts.
As was suggested above; mark them accurately and measure the existing LC.
They may be out or jumped a tooth but it will give you a number to think about.
AL
Posted: Mon Dec 21, 2015 8:51 pm
Author: tlc
Well, having tacho drive threads they are not Unitrak specific whatever they are.
Posted: Tue Dec 22, 2015 5:40 pm
Author: pluto
Hi and thanks for the responses, went back to the garage and had another look, found these numbers on the bit that the sprockets bolt to. The sprockets did have marks which lined up at tdc and were the required number of rivets apart. What do the numbers mean and are they suitable for a road / track day bike?
Thanks again,
Dave
Posted: Tue Dec 22, 2015 6:14 pm
Author: pluto
I think ive just answered my own question. Found 470-25 is a megacyle cam part number for cams suitable for gpz1100. 0.417" lift and 268deg duration. A road race cam for high comp pistons (+12:1 at least) which Im not sure I have.
Might just put some standard unitrac cams back in!
Posted: Tue Dec 22, 2015 7:23 pm
Author: zed1015
Yes! Megacycle cams for Z9 to GPZ1100 .
0.417 lift on 107 centres.
Road race or Drag race.
