Starting a Rebuilt Engine

chris68 · Post by **chris68** » Tue Jan 31, 2006 8:14 pm

Anyone got any tips for getting a newly rebuilt engine started?

It's a 2.0ltr S motor with webers. I've got good oil pressure when cranking although it's cranking slowly. I've checked battery and starter electrical connections and there all good.

I've checked the static timing (5 deg BTDC) and there are good sparks at the plugs. The webers have been rebuilt and initially setup as per the book. It coughed a few times but refuses to go.

Anyone had similar problems in the past??

Cheers,
Chris

Alan @ CanfordClassics · Tue Jan 31, 2006 8:25 pm

It sounds like you know what you are doing, so just be logical. I have had similar problems in the past and it was because I was in a rush to fire it up. Check it all again, spark, fuel, and air, and if it's done properly it will start.

Good luck

Alan

davidppp · Post by **davidppp** » Tue Jan 31, 2006 8:40 pm

Sounds like you need more oomph.

Ther is a lot to be siad for a tow start IMHO..

Cams do not like being ground against the followers with little lube spray..ie at low revs..

Once it fires, keep it at about 2-3000 for at least twnety miniutes.

In the first few minutes, its cams are your main worry..

After that start to thrash the rings with some full throttle/off throttlew stuff..

Don't rev the bearings over about 5000 for a few hours..

Enjoy!

Kind regards
David

chris68 · Post by **chris68** » Tue Jan 31, 2006 8:52 pm

Thanks for the suggestions. Nice to know others have been in the same boat.

I'm wondering if the old starter hasn't enough grunt to crank quickly enough. The motor turned over freely on the bench, but now under oil pressure and compression the starter seems to struggle.

I've read other posts about the early 0.8hp starters being a bit under powered.

Can a later, more powerful starter be used?

Cheers,
Chris

davidppp · Post by **davidppp** » Tue Jan 31, 2006 8:57 pm

Yes, sure.

But what I have done..in fact always did with the ancient Ford BDA's etc.. was use two batteries for the starter.

Not a problem if you do not flog it..

Use another for the sparks of course!

Kind regards
David

davidppp · Post by **davidppp** » Tue Jan 31, 2006 8:58 pm

Sorry, meant 2 in series..24Volts..
Another, to give 12V for the spark..

Kind regards
David

Alan @ CanfordClassics · Tue Jan 31, 2006 9:29 pm

Like I said, maybe get some more power (oomph) and 9 times out of 10 that will be the issue, but if check things through and it will start.

Good luck,

It ones of the nicest sounds when a motor runs for the first time.

Thanks

Alan

impmad2000 · Post by **impmad2000** » Tue Jan 31, 2006 10:15 pm

and make sure you are using some fresh petrol. Modern stuff goes off in a matter of a few months ! Once it is running, old petrol will probably keep it going though. Just a thought, good luck.
Tim

Barry · Post by **Barry** » Tue Jan 31, 2006 11:24 pm

I'm with Tim, modern fuel seems to go off so quickly: certainly when combined with a slightly tight (new) engine, perhaps initial carb set-up etc.

I'm sure you've already got your spare oil filter and oil ready: drop it after those first twenty minutes (time them: I was convinced twenty minutes had gone, it was nearer five!). When you drop that oil, catch some in a clean jar and have a squint at it: don't worry if it looks a bit pearlesent, do worry if there's chunks in it

I then did another oil change at 100 miles (kept it on the 2nd filter) and a third (new filter) at 500: not that I'm sad or anything.

One other thing: you'll hear about making the rings work with a combination of power and then over-run: don't over do the over-run bit. Obviously the closed throttle shuts off the fuel, flame goes out, cylinder starts to cool. If the engines just been worked fairly well (up a long hill perhaps), then you engine brake down the other side, the cylinders are quickly cooled because the fan's still going flat out and can contract. It's quite a problem on light aircraft: fresh engines being known to seize.

Anyway, don't worry about it, just don't hoof it up a long hill, and engine brake all the way back down: load and coast in moderation

Good luck with the start-up. I was so nervous I nearly puked!

BTW, mine billowed white smoke for the whole of the first twenty minutes. As soon as it hit the road, it all cleared up, never to be seen again.

veryporky · Post by **veryporky** » Thu Feb 09, 2006 12:01 am

You an aircraft man Barry? I've seen many a Continental or Lycoming with pots severed near the cases and heads severed from pots. Glider tugs are the worst, long slow climb with glider on back hot and bothered low airspeed with poor cooling airflow. Pilot ditches glider and stuffs the nose down with throttle at idle to pick up the next one as quickly as poss. Result like crash cooling. Cracks big time.

Barry · Post by **Barry** » Thu Feb 09, 2006 10:30 am

My Dad's a licenced aircraft engineer (avionics), both parents were solo glider pilots (Dad had 1/4 share in a glider, and was the winch driver at (I think) Lasham).

I've also got a couple of friends with light aircraft: although my only claim to fame is that, apart from the first take off, I've flown a Piper Archer from Sussex, landed at Calais, took off again, and brought it back to Sussex. Would you believe, a fortnight later, the plane was in the air when the dash caught alight: the owner did an emergency landing and watched the plane be totally burned out

. Wasn't me, honest

.