Dyno Run In - Formula Ford Kent

hawke · 07-06-2010, 01:29 PM

I've just finished rebuilding my Formula Ford Kent engine, and it looks like it will be some months till a free day comes up at a local track to run the engine in.

Can anyone recommend a Sydney chasis dyno operator that can help?

Engine Guy · 07-06-2010, 06:29 PM

Hmmm...

What makes you think it needs running in on a chassis dyno? is the motor 'tight'?
Cheers
Engine Guy

hawke · 07-06-2010, 06:36 PM

To get full power on these things, getting the rings bedded is important. The only way to do this is under power, particually in the first hour of operation, and by using a dinosaur oil.

You can get some glazing in the bore, and some blow by just by letting the engine warm up just after build up.

Depending on the piston clearance and chamber volume, spark settings do change to maximise power. Settings range from between 37-41 degrees.

Motor isnt tight, crank and piston clearances are on the high side, but ring end gap is low - 0.008" installed. Should expect to see 0.010" after a few sessions.

Engine Guy · 07-06-2010, 06:47 PM

The FF race engines I used to build in the UK....had the rings/pistons individually lapped to the bore... amongst lots of other things we did...

Cheers
Engine guy

hawke · 07-06-2010, 07:17 PM

Engine Guy, I dont fully understand your point.

All the bores have been honed and sized to fit new pistons, and rings have been gapped to suit. Pistons have been machined down to get the correct weight, exhaust valve clearance and combustion volume. Cam timing has been retarded 4 degrees. New pump gears and rotor fitted. New hoses fitted.

Not only do I want to see it on the dyno, just would like to confirm no oil leaks or pressure issues.

This is the second build this year. At the last build, the crank was replaced due to a crack. The drilling of the new flywheel bolt holes was 18 degrees different, and we timed the ignition 18 degrees out. Result was melted pistons after 7 laps of Eastern Creek. When you are running open exhausts and in a session with F1 F2 and F5000 cars, you cant hear the detonation.

V8falcons · 07-06-2010, 08:50 PM

Love formula fords my self,Use these guys http://www.unigroup.com.au/Home.html
Our club the small ford car club. http://sfcc.mine.nu/ just had a dyno day on saturday,and is a small ford fan himself.

I missed out on the dyno day as my engine was just rebuild and required a few minor tweaks before a thrash on the dyno.

cheers

Engine Guy · 08-06-2010, 09:26 AM

Quote:

Originally Posted by hawke

Engine Guy, I dont fully understand your point.

I was trying to give you some advice based on over 28 years experience regarding engine preparation....
the various engine settings you mentioned 'seem' to be a bit odd...how did you arrive at 4 deg retarded on the cam being correct? why is 18 BTDC your static ignition setting?
If this was my project, i'd probably do a basic install in the car, go to a rolling dyno - and do the basic checks, AFR, ignition etc etc...
Sounds like there was a serious error / problem before!!

But good luck trying to find a engine dyno
Cheers
Engine Guy

Puzzlescort · 08-06-2010, 09:49 AM

Hawke

ring Paul at Boreland racing and say Scott (Puzzlescort) said give hime a call, even though they are in Melbourne I am sure he will know someone in NSW familiar with FFord engines

cheers

hawke · 08-06-2010, 10:54 AM

Engine guy,

Thanks for that, but perhaps I didnt explain fully. The 4 degree retarded on the cam, brings the intake cam centre line to 112 Degrees BTC. Standard was 108 on the new chain I was using. Using the 112 degree setting certinally gives better top end performance, and seems to be the "hot" thing to do. I have found that it gives about 250 extra revs at Phillip Island and Eastern Creek.

The ignition timing is nominally 38 degrees BTC at 5000 rpm, but the new crank was indexed differntely, and added another 18 degrees into the equation - 54 degrees. Piston broke, and bits of aluminium went all through the engine. What was strange, was the engine started and went fine, but we couldn't understand why it overheated over 5000 RPM. Checked the timing, but when the mark is in the wrong spot, it doent jell. When checking TDC to time the cam, the degree wheel is set independenlty of the crankshaft marks. Expensive and annoying lesson learnt.

Engine Guy · 08-06-2010, 04:40 PM

The 4 degree retarded on the cam, seems to be the "hot" thing to do.

Hmm... 'hot thing to do'... camshaft selection and timing is a bit more involved than that... a while back I ordered 10 'identical cams' for a FF Kent, and installed each one in turn - result was 8 deg difference across the 10
'supposedly identical' camshafts!

I would definatley do a run and check oil pressure, timming, AFR's etc etc...

You might find it hard to find an engine dyno, let alone one that's jigged for a kent engine...

Just my 2c's worth..

Good luck
Engine Guy

hawke · 17-12-2010, 03:59 PM

Track run-in did not work properly.

At the last race meeting at Sandown, couldnt pull revs, and was getting passed on the straights by almost everyone. Compression in two cylinders down 30psi.

Have now rehoned those bores, and ran the engine under load at a local chassis dyno. After 20 minutes of running, oil blow by stopped, and power increased by about 9%.

Engine Guy · 17-12-2010, 04:40 PM

Hmmm...

Sounds like you still have issues.

Building a good FF engine is a very time consuming process, measure then measure again.. everyone makes mistakes now and then though - so no shame in that.

Pity you aren't in Adelaide/SA I could surely help you out for small fee / advertising..

Cheers

Engine Guy.

peterw · 19-12-2010, 12:14 AM

Dyno is the best way to run in a race engine. Everything can be can be strictly controlled. It's worth the effort.

Pete

xmwagonist · 21-12-2010, 08:12 AM

We always run our racing engines in on a dyno, engine is nice, but if not you should be able to use chassis (rolling road) style, but with associated gearbox/drivetrain wear and tear. I remember the old days of group A, seeing the BMW team doing laps running in their engines though, just harder to control the result and making sure the driver does it properly!

hawke · 14-03-2011, 05:49 PM

The extra 9% power seemed to work. Best time 1:07.5, which I was happy with. A 38 year old car, with an even older driver. No car out accellerated me on any straight.

Some video for your enjoyment:

http://www.youtube.com/watch?v=DW9I01VxVEo