Modified 1980 Dyno Run with Graph

[djape1977]

call dyno shop and find out if it's wheel hp or calculated flywheel hp on the graph.

[joelittel]

They said " This is actual wheel hp based on parasitic losses. "

[djape1977]

ergh...
so you're running modified engine with 100hp at wheels.
last time i modified one, it was 1800cc and it pulled 125hp on wheels and that was just using stock parts from fiat range.
congrats, now you have bog standard euro spec 2 liter

[joelittel]

That's funny to me because I originally proposed this build to my wife as "wanting to get the car up to European spec."

After combing through my build notes I think I've found my mistake.

When setting my cams I made clear notes on finding TDC and Full Lift, etc etc but I have nothing in my notebook about dividing the full lift at X crank degrees by 2 to find cam position A. Then retarding intake and advancing exhaust by A.

Cams rotate twice as fast as the crank, so you compensate by dividing crank degrees at full lift by 2.

I don't remember doing this step, I have no notes indicated this was done and I did not mark my pulleys for A, only Full Lift. Croft recommends using a red dot at full lift and a white dot at position A. I marked the pulleys with a red dot but never marked position A with a white dot.

From what I could see, based on my red dots, my cams are 54.5 degrees off. The amusing detail here is that even with this potential oversight the car is still better than it was when I got it. Thank god it's not an interference engine.

So.... tomorrow I'll make sure the cams are set according to Croft's book and see what happens.

I haven't forgotten about the pictures, will post when I can get to my desktop machine.

My Spark advance is very similar to the mechanical curve in Crofts book, figure 11/6 page 139. Slightly advanced but very similar.

[joelittel]

finished timing the cams last light and as I suspected they were off, but only by 10 cam degrees each.

Both are now set at 109 crank degrees.

Previously they had been set to 104 crank degrees. I thought I was being careful when I set them the first time but apparently I was not.

Looking forward to seeing what difference this might make. I plan to put it back on the Dyno in a few weeks.

[So Cal Mark]

" but only by 10 cam degrees each"
that's quite a bit actually

[joelittel]

" but only by 10 cam degrees each"
that's quite a bit actually

Every time I think I know what I'm doing I discover that I have a lot to learn. This forum has repeatedly saved me!

That being said....

I purposely did not put everything back together entirely so that I could check my work a few more times.

[FiatMac]

finished timing the cams last light and as I suspected they were off, but only by 10 cam degrees each.

Both are now set at 109 crank degrees.

Previously they had been set to 104 crank degrees. I thought I was being careful when I set them the first time but apparently I was not.

Looking forward to seeing what difference this might make. I plan to put it back on the Dyno in a few weeks.

Cams turn at half the speed of the crank (2 turns of the crank equal one turn of the cams). You were out 5 crank degrees so that was 2.5 cam degrees.

[joelittel]

Thanks FiatMac

Like I was saying, I have a lot to learn.

[joelittel]

These were shot at Dyno Source Performance Inc.

[joelittel]

I tightened everything up and started the car up tonight.

My first impression was that it fired up very easily. I haven't tuned the warm up enrichment yet because I read that you should have your AFR and VE tables dialed in before even considering tuning the warm up enrichment, so I was expecting more of a struggle to keep it running until warm. In the past I'd have to attend to the gas until it was warm, especially right after startup. This time it required less effort on my part and settled into a steady idle much sooner. I still had to give it a little gas until the temperature came up, but less than before. However, the ambient temperature is warmer now then it was two weeks ago though which could be helping me.

It also cracked over fewer times before coming to life. Previously it would take longer, like 1-2-3-4 Vrooom. Tonight it fired up surprisingly quickly after turning the key.

I haven't tuned the idle yet, I only data logged a few startups and tried to burn off the oil I spilled during the teardown (cam towers had to come off) and seems that oil found it's way everywhere. I never let it get past 190 degrees because I didn't want any oily spots turning into black char spots on my engine.

Tomorrow I'll wash off whatever's left and then start to tune the idle.

So far this all makes me very happy, and I can't wait to drive it.

[phaetn]

waiting with bated breath. Is there another dyno run in the near future?

Cheers,
phaetn

[joelittel]

There is, but have not yet set a date.

I've had a few smaller issues pop up that I've been fixing while tuning the new setup. One of which is an annoying exhaust leak near the muffler... just came out of nowhere one day....

So far I've noticed the car pulls higher into the rpm range than it used to, which I'm taking as a good sign. It also starts easier than before too.

[baltobernie]

[joelittel]

If I can get my exhaust issues buttoned up this weekend I'll schedule another dyno day soon.

Currently though, I don't feel like there have been big gains. It definitely drives better than before but I don't expect a large increase in my numbers.