so , a new project looms ,
its a 1.6 x16xel vauxhall engine ,to be used for rd use on propane and no cam change .
so far i have read that the inlet maniofld was highly restrictive ,and so tested it on my flow test apparatus (read'lash up' ) and the head flowed 171 cfm@25 and the lower inlet 154 and the upper inlet 133 !
so thats all been cut up and now im making a 4 straight 41mm tube stonko manifold that will flow a big amount wilst still keeping up velocity .time will tell.
cams wize ,gm time them in at 108 and 99 lca ,so thats all changed to 110 and 113 , iv made an assumtion that the 99 ex timing was to drop cyl pressure for emmision purposes .
i will port the head and top exhaust manifold ,hoick out the cat ,and feed the dog ,er no , i mean remove the catatonic converter .(its getting late) .
little bit indecisive on the valve to piston clearance i can get away with , when on normal gm cam timing it was 1.04mm ex and 1.46 in . now its at 2.48 ex and 1.42 in .most clearance charts show 80 and 100 thou for valve clearances ,so im well below that allready , is it safe to wack off .38mm to get down to the original gm setting ,that was on the ex, and would now be on the inlet ?,
that would take my cr from 10.48 to1 up to approx 11.2,not as high as i would like but better than nothing ,particularly for economy.
cams are 8.5mm lift and 1mm timing 216 in 224 ex .
any input on the valve to piston clearance greatfully recieved ,
heres some pics ...
regards robert