hard to crank / start when ignition timing is set correctly advanced -- x/flow

[alfas]

i have installed an engine which was running b4 in another car over years. (unfortunatley i havent seen it running, but the person i got the engine from could be trusted)

its a mildly tuned x/flow, 1700cc, stage3 head with double valve springs, duplex-chain, sportscam from kentcams (unknown spec), twin 40ies..
if you turn the engine by hand with a spanner , spark-plugs still fitted, its moving smooth and you dont really need a lot of force.
i have had standard x/flows which needed more force.

before i installed the engine to my car I fitted new piston-rings, and new bearing shells. shells and rings with the same size/spec like the ones fitted b4.
the engine was only partially dismanteled for that. the cam-timing was not touched, nor was the chain off!!


if the engine runs, it runs very quiet with stable idling.

but the starter has problems to turn over the engine. its like the ignition is too much advance.
this said, the ignition timing is set to 12degrees in advance. (so could be even set more in advance)

if i change it to less advance or even zero, the starter turns over the engine easier, but the engine does not run properly wth lack of performance.

starter motor type: pre-engaged
battery is a small gel/race battery
electronic dizzy ignition, which was already fitted before to my other engine
this combination (starter / battery / dizzy ) has worked well with other two x/flows in the same car

summary:

-ignition set with correct advance -- hard (nearly impossible) to start
- ignition set more tp TDC - easier to start, but lack of performance

any idea what i can do?

[Graham]

you need a distributor which has more centrifugal advance, that way to can run initial advance but still have the advance at higher revs where you need it

[alfas]

but this would mean i would need to install a dizzy which is able to create around 35degrees advance by cetnrifugal!! quite impossible i guess?

[alfas]

also made a quick check of approx. valve timing: crank on TDC -->the valves of the 4th are inbetween rocking.

[Miniliteman]

Engine should turn over with 12 degrees advance at idle.
Guess the new engine has alot more compression that the old engines, hence the difficulty to turn-over.
Try and replace the battery with a proper item and make sure the terminals on the wires are properly crimped-on.

[fatboy slim]

clean and check all earths

[daniele]

a booster will tell you more

[alfas]

yep---the additional battery / booster is a really good idea for a test

[alfas]

Engine should turn over with 12 degrees advance at idle.
Guess the new engine has alot more compression that the old engines, hence the difficulty to turn-over.
Try and replace the battery with a proper item and make sure the terminals on the wires are properly crimped-on.

i remember now, its around 3 years ago, i was owning a sylva strier with x/flow....and it had the same issue.....but that car already had a proper battery (we even tried it with a new one)...i sold the car. to finance a new project..the new owner "lived" with that problem.....the next owner put the car on a rolling road..and the engine made 135horsepower.

[alfas]

problem sorted...as expected my electric wiring / earth etc. was spot-on.
pre-engaged 0,8kW starter OUT, pre-enganged 1,4kW geared starter motor IN

[katana]

Going back to an earlier comment 12 deg btdc static / idle and 34 deg advance? Why would a hi comp x flow engine need 46 deg total advance - that once its there, can't be reduced unless the dizzy has a can for retard? Something with mappable ignition may be able to use those numbers in mid range but guessing nearer 30 deg total would be better? Not telling, just asking?

[Miniliteman]

Going back to an earlier comment 12 deg btdc static / idle and 34 deg advance? Why would a hi comp x flow engine need 46 deg total advance - that once its there, can't be reduced unless the dizzy has a can for retard? Something with mappable ignition may be able to use those numbers in mid range but guessing nearer 30 deg total would be better? Not telling, just asking?

Guess "alfas" means he needs a total of 35 degrees BTDC timing at high rpm, so from a static 12 degrees that is 23 degrees advance (which is common for distributors).

problem sorted...as expected my electric wiring / earth etc. was spot-on.
pre-engaged 0,8kW starter OUT, pre-enganged 1,4kW geared starter motor IN

So high compression meant the old starter wasn't coping anymore.
(std pre-engaged starters are 0.7 BHP so about 0.5 kW).

[alfas]

Guess "alfas" means he needs a total of 35 degrees BTDC timing at high rpm, so from a static 12 degrees that is 23 degrees advance (which is common for distributors).

exactly. my former post was related to the fact that i need a total advance of 35 degrees.

with a dizzy set to zero (TDC) to make it start with a non-powerful starter-motor, i would be never able to create 35degrees advance by centrifugal.