new engine timing out

[TNT!hammond]

It seems i have maybe got my timing a little out on my new engine build, engine is in and struggles to start / does't really start . I decided to do a comp test to see if the valves where to blame, only tried one cylinder but i only got 90 psi, this is with new pistons, liners and rings so im guessing my timing is retarded like me after reeading a recent thread.

The cam is a msm one and its timed correct to the cylinders ie valve 1 and 2 move with comp stroke and exhaust stroke of cylinder 1.

Engine turns over great with no plugs in but with the plugs in it really struggles.

I took the rocker cover off and while it was in the car hooked up a protractor and a pointer, i brough the fly wheel to tdc so inlet was the next valve to open, i set the pointer to tdc on the protractor and unfortunaly i dont have a dep gauge? its elsewhere at the mo but by feel and sight then moved the bottom pully round, the inlet valve stops moving at 112 atdc but then moves again around 130 atdc so im guessing im timed in at around 121 atdc would this equate to roughly 1 tooth out on the vernier? also at tdc the dis points off parralel slighty not over amounts but noticable, any ideas people of what i can try would be greatly aprecciated .

with thanks ross

[Rob@Backyardracing]

yeah could be a tooth out or a bad piper grind, need to reset and start over...

[TNT!hammond]

ahh bugger, would this also cause the difficulty to turn over with plugs in rob?

also when timing the cam do you,


find the angle when depth gauge stops moving,keep turning till it move again ie my 112-130 add together then divide by 2 giving a time of 121 atdc it seems that the valve stays still for quite some time and ive thought it was correct at 112 but not realized it would stay at may opening for yet another 18 deg . As i say any help appreciated and thanks for the reply

[Rob@Backyardracing]

whats your battery like? does it turn over pretty well?

[TNT!hammond]

yeah as i say no plugs it turns over like mad but with them in it really hates it ill try it again after the cam maybe with my 2.5td transit battery on to see if that help, my battery is only a little red top one 5kg . Maybe as the engine is new and tight it doesnt have enough cranking juice ?

what is 1 tooth on the vernier then? ill have to do it in the car now though bugger that will teach me

[5teve L]

Doing it in the car is a right ballache, i did it once (well a couple of times) & i could never get the bloody cover to seal, tried 3 or 4 times
Hope you have more luck than me
I had one of my builds out by a tooth once with a k-tec cam, stared fine but would struggle to rev past 4k on the road..

[Andrew Cooke]

I start at looking why it turns over slowly, low compression/retarded timing would let it turn over more easily than normal. You may have more than one problem - how good are your earth straps? Have you been painting things that should conduct - such as where the starter motor bolts on.

[TNT!hammond]

Been outside since 8 this morning , i hooked the diesel up to the battery and put a weight on the throttle to rev to 2k , jumped in the 5 and turned it over with plugs in and it turned over alot better was really close to starting, i then remember its always started better with the wire swap so i quickly tried this and bang it started , sat at 2k for a while and then let off the throttle gently and it wouldnt rest bellow 1000 rpm . I killed it and changed the wires back to std again and tried to start it and once more bang it went this was off my red top battery alone , revved again to 2k for a while and when i let go it idles spot on 750rpm quite low for the cam i would of said .

i then did a new comp test on the same cylinder and i got 145 on the cylinder i first tried. I then did a static timing light test and its 8deg btdc with vac pipe off .

Could the original comp test and turning over issues just of been the cranking amps of my little red top battery?

Andy i have 3 main eaths, i just checked and they all seem ok 1 may have a little paint on it that ill scratch off , ! of the earths is basically a piece of house main its that thick lol.

thanks for the previouse help and more ideas and info would be very welcome

[Andrew Cooke]

what do you mean by house main? You need something that'll do for 2-300A

[TNT!hammond]

Its around about 15mm in diameter so rather large, i then have 2 earths that are normal battery earths are these no good Andy ? if not ill go get new ones and re bolt them on, last engine had the same ones .

[Andrew Cooke]

Its around about 15mm in diameter so rather large, i then have 2 earths that are normal battery earths are these no good Andy ? if not ill go get new ones and re bolt them on, last engine had the same ones .

that sounds fine, I only use one earth.

I think all my power stuff is 16mm2, It's a while since I bought it, so can't be sure.

The point is to ensure you have good electrical contacts from starter to gearbox to engine, to chassis, to battery. Painting stuff can give problems if you're not careful.

[TNT ANDY]

that sounds fine, I only use one earth.

I think all my power stuff is 16mm2, It's a while since I bought it, so can't be sure.

The point is to ensure you have good electrical contacts from starter to gearbox to engine, to chassis, to battery. Painting stuff can give problems if you're not careful.

Hi andy,

The main earth from Body to engine (LHS) is about 50mm the RHS is more like 16-25mm .

This is all achademic anyways as Ross had it running by the time I got there. Sounds nice.

Nice one Ross.

Just to go back a few posts though, I would assume that the poor turning of the engine and the relatively low compression to be the new rings and Bottom end bearings not being run in. I no experience of this but I would have to guess this be the case.

[TNT!hammond]

thanks Andy , Rob and Steve . All is good now i think something is robbing my battery of juice it would seem at the mo , while running i get 12.6v across the alternator and battery , but if left for ten minutes i try to start the car again and the battery wont crank it over , time to see why

[Markey Mark (BD)]

If your only getting 12.6v across the battery while the car is running looks like a charging problem mate.

[TNT!hammond]

cheers mark im on the hunt to order a new alternator from these guys at the mo www.powerlite-units.com may get a starter too as the engine is coming out again too bloody drippy boxes