Cam , carby problem , maybe

[madv8bike]

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Hey everyone , new here on this forum , putting this 161 motor together and run into some trouble , 30 thou over , Thomas cam ,specs unknown, Yella Terra stage one / two head , anyhow cant get it to run right , cant get to idle or run sweet ,I have used the carby from my old 186 ,Bxv 2 , changed carby s , rechecked everything, suspected I have got cam timing wrong , I fitted a new jp gear set , I have built many engines and degree d many high performance cams so I doubt I made a mistake, just fitted as per Holden manual as I dont have the cam card for specs ,,
Anyhow got chatting to a guy done up a few old reds , tells me about some cam shaft grinders 40 to 50 years ago who matched there cam timing and gears ,you have to use the gear supplied with the cam , dont match the holden keyway timing ,
Anyone know about this before I pull it apart , this cam is a new Thomas 141 grind I have had for 40 years ,,,,
Have completely changed ignition, removed inlet manifold , no leaks
But could it be the carby , will a 161 run ok with 186 carb , i have tried rejeting , cant get to idle properly, idle wound right up to end of adjustment ?????

I suspect it is the cam , next step put a standard cam in , anyone got any ideas ,

[madv8bike]

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[basic.green]

manifold leak maybe

[madv8bike]

Na , first I checked, twice pulled of manifold ,
,,, maybe the lifters next to check , my mate gave me the cam an lifters 40 years ago , the lifters maybe solids that are built like hydraulics to comply with a speedway class , where the rules says hydraulics only , so when I get back to shed I adjust them as solids , i did not get any paperwork with them ,

[madv8bike]

Found troubles,
My hydraulics lifters are set to run as solids , set lash to 10 thou and runs fine , the cam and lifters come as a set , I did not get the paperwork or any specs , 40 years ago ,

A Thomas cam 141 grind ,
There used to be some speedway classes where the rules say you have run a hydraulics cam and lifters , these lifters pump up and dont bleed off ,

[Errol62]

Makes sense. You could go a bit closer maybe 0.005”?


FB ute fixer upper, EK van on rotisserie

[madv8bike]

Idles and drives ok now , just setting valve lash at 10 thou ,
Have gone up a main jet size bit better,
Eng still feels lazy

I think should just chuck that cam and lifters in bin ,

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Ron
Maybe you should tell the viewers about
your Blitz ,it is a bit of a icon or one of your bikes

Rob

[madv8bike]

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