Monday 17 March 2014

Engine Dyno Session

I'll give you the pictures first (some are blurred - sorry, these are the only ones I have as the day was so busy), then a summary..............

The engine (finally) at the Dyno shop and the drive hub mounted to the crank.




 
 




































Above is the actual Dyno unit and the engine all hooked up. I started to get very vervous that this point...... And below is just one of many interim results showing it got 525Hp and 596Ft/Lbs of torque when being mapped at 70% throttle. The two "gauge" displays at lower left keep the last set of results and the photo below that shows the mapping being done at the various load and rev' points.
We had just run it from 1000 to 6000RPM while holding 70% load (throttle position in my case).
This is how the Autronic EFI unit is tuned and you need only 1 or 2 seconds at each tuning site.
So once everything is setup, it all happens pretty fast. Trouble was - it took a long time to setup.








































And finally - the actual dyno sheet. 604Hp and a nice flat torque curve that sits in the mid 500's.
The dyno sheet doesn't lie - and this is my baseline now. However, this is just part of the story and I believe there is plenty of room for improvement.

 
 
 
 

 
 
 
 
 
 
 
 
 
 
 

Why do I say that? Because this run was the only one I could do as I ran out of time and money.
There was a lot of sorting required to get to the actual final "run".
Major problems were.....
  • Harmonics caused my crank sensor to oscillate and hit the trigger wheel. Had to fabricate the whole thing again on the day.
  • My initial spark plugs (suggested to me) were the wrong heat range. Found replacements (thanks John) and it was a very (incredibly) different motor.
  • Worst issue was some of my glyptal internal engine paint flaked off and blocked the finer stainless mesh filters I had located inside the dry-sump itself. My fault - 100% no doubt.
  • This meant oil was pumping in ok (from a large reservoir) , but not escaping at all for the dyno run.
So I only got the one run done and ran out of time to put some ignition advance into it. The above figures came at 25 degree max advance - no danger of pinging at that rate.
Just as importantly, the above figure came with at least 12 litres of oil sitting inside the dry-sump and crank case. I took 12 litres out when I got it home, but heaps had already leaked out. That engine probably thought it was trying to sprint in thigh-deep water......
 
I've sorted out the "paint flake" issue, and I'm hoping that the 596 Ft/Lbs I saw earlier (when tuning) was in a large part lowered on the dyno run because of the oil issue.
 
Also, see how the HP figure flat-lines at about 5750RPM?
Again, I'm hoping that is because of the retarded timing I went in with - because I know the induction, fuel and spark are good to go to about 8000RPM. Not that this engine will ever see those kinds of rev's, 6500 will be my conservative limit I'd say.
 
But - the EFI is now mapped and I can install it in the car and tweak it from there. I'm happy to say I have a reasonable base to work from now (solid engine) and there should be a big "upside" with some more tuning. Putting in some more ignition advance should really make a difference (make it jump) I'd say.
Anyway, now a couple of recent photos. First of the new filter screens I've built - to stop anything dropping down those (large) ports. I'll have a proper cold air box with normal filters in the final configuration. But these make me feel a lot safer for now.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

And here is the latest photo showing that I'm just about to slide the Tremec into place.
Had a false start with the original hydraulic slave cylinder (too short), but the new 1400 series McLeod unit has fixed that.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Thinking ahead, the next post should be of the engine going in. Or maybe the interior - as I've been working on that in parallel to the above engine "project".