16 replies to this topic

[minilee94]

just built my 1380 engine 285 cam , brand new crank , ultralight flywheel from med , weber 45 carb etc

I had my engine running a while ago and the fan smashed it's self to bits somehow

Anyway before that the engine run pretty smooth but now iv put a 2nd had fan on and the engine vibrates a lot on tick over rpm is at 1000rpm

Too fan off today run the car for small amount of time with no alternator belt on, no rad in etc and it still vibrates quite abit

What else can it be or is it just that the engine hasn't been set up yet

[Steve220]

Did you have the bottom end balanced with the flywheel and clutch?

[minilee94]

No according to med it didn't need to as the flywheel is already balanced along with med alloy crank damper

[minilee94]

And it ran fine before not vibrating till I broke my fan but braking the fan can't do any harm

[petey81]

Have you checked the water pump pulley?

[minilee94]

Yeah is okay and as said it still vibrates even with all that off

[petey81]

Soz just read that! Stupid me.
Prob just needs setting up then.
Whip off timing chain cover and check around there, ie crank pully bolt, sprockets and so on.

Edited by petey81, 09 January 2015 - 05:42 PM.

[minilee94]

Yeah checked all that today

And would it not being set up really cause that to vibrate though

[petey81]

Yeah its like when you start a car with choke then quickly push it in. My vibrates everywhere until warm.
If you know what i mean

Edited by petey81, 09 January 2015 - 06:01 PM.

[minilee94]

Yeah quite like that

[Spider]

At a guess, I'd say the Harmonic Damper is Karput.   I wouldn't run it until it's sorted though as you could be asking for a busted crank.

[Oldskoolcool]

Have you tried running the engine at a faster idle speed?

With the spec of your engine you will never have a smooth idle at a 1000 revs, the ultra light flywheel won't help the situation!

With a high lift cam and a big Carb the gas speed is very low at low RPM'S, adjusting to higher tickover speed can help.

I saw in a previous post that you were having trouble with wet spark plugs, are you using the correct heat range? If the plugs are the wrong heat range to suit your spec this might also be part of the problem.

[Steve220]

No according to med it didn't need to as the flywheel is already balanced along with med alloy crank damper

The moving parts will inevitably weigh more when bolted together which changes the harmonic balance.

[minilee94]

Hi moke spider the damper is brand new from med

Also old skool cool I am running plugs that bill Richards had eavised me to run for the time being and yeah I see what you mean by the carb, cam and flywheel etc but as said it ran fine before

And I will try and raise the rpm on Sunday and see if that helps

And Steve but surely that don't make that much difference as many company's I used I asked if to balance and they all said no that's why I didn't do it

Edited by minilee94, 09 January 2015 - 09:15 PM.

[Fast Ivan]

what does Bill Richards suggest?