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Bill Verburg Bill Verburg is online now
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Join Date: Dec 2000
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Quote:
Originally Posted by spyerx View Post
Can I pile on here?

2.7 S motor (in a 71)
Webers
SSI Headers
Distributor from Partzclassic, curved by them, with Pertronix, No vacuum adjustment
Stock cams, heads, CIS pistons

Should I target about 38 BTDC at 5500??

Thanks :-)
most likely, but use your senses and if possible check on a dyno

basic timing for all the early engines whether T, E or S was
TDC @900+/-50rpm & 38° +/- 3° max

They moved the 900 rpm spec a bit + & - so go by the spec for you year and experiment a bit tp get best idle but the max is fixed and actual values could be anywhere from 31° to 38° BTDC @6k
rule of thumb
all ° BTDC
100 3.5-6.5
1500 4.5-14
2000 16 - 24
4000 24 -31
6000 31 - 38

for the idle Ca cars were spec'd @ up to 15° ATDC which is really retarded and generates a lot of unnecessary heat
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Bill Verburg
'76 Carrera 3.6RS(nee C3/hotrod), '95 993RS/CS(clone)
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