Went up to the do at the Wingspan club today and they were doing cheap power runs on a local dyno. Eventually got on there ...mmmmm....not what I was expecting.

The last line of mods was to dial the cam in correctly with a vernier pulley and dial gauge ,ended up 6 degrees advanced from previous position , and to put on a known good DGAS from the POS. Felt a lot torquier out on the road though the long run today showed up surging at 3000-3500 in top.


Now ...the power run. Performed in second gear ( almost normal 3rd auto due to the tall gearing) and it made 76bhp at 5803 compared to best previously of 80.2 at 3250 ( in third).

Torque DROPPED from a best of 120lbs @ 2200 but falling away to 60lbs at 4000 to a best reading of 87lbs @ 2400 to 76 @ 4000.

Running way rich on the machine,no printout ( 23mpg on the run) , hence the surging ..though the carb ran fine on the POS.

I thought advancing the cam ( beyond correct timing) was meant to bring in more torque earlier yet I had more torque earler ,but falling rapidly ,with timing 6 degrees retarded from 'correct' cam timing .

WTF is happening ? Seems the more I fix the worse it gets ??
__________________

Kev, when I ran the pinto in Tetanus I could only use fifth on the motorway over at 70mph and if I knew that I wouldn't want to put my foot down, it would pull around the 90mph in fifth and around 95mph in fourth. I changed from the 3.7 diff to a 4.1 and it changed the car sooooo much, I could use all the gears as I should and MPG went way up, plus in the end I saw 115mph on the sat nav (on a private test track officer) I'm lead to believe that the axle was from a 1300cc 2 door mk 3, sadly it let go in a big way on the first run out with the rover (the traditional out of the garage straight to big burnout wasn't such a good idea:****er
I know that doesn't help much, but stick some 13's on the truck and it'll tell the tale.
Chaley

110 ...so about a true 100 at 18mph/1000 = 5500rpm?

Mk3 GT when it was a fairly new car would show just short of 110 on the clock, had a Mk3 that had a stock 2.0 engine, 1600 box & axle, ran low 17s all day long, by no means Earth shattering but deadly consistant.

Originally Posted by Hemi Bucket

No different on the last test thrash then Kev? I was thinking on the way home, when you say it's got 3.89:1 gears, have you counted the ring & pinion or are you going by what the axle's supposed to be from?

Literally just walked in from looking underneath as I was thinking along similar lines. B type axle ,2000 car only which makes it a 3.7. According to Haynes A type axle 3.89 fitted to 1600 and 4.1 option on 1600 saloons and estates.

Definitely pulling stronger but not reving past 4000 in top which is a true 80mph against satnav.

You've had loads, what woudl a Cortina 3/4/5 saloon top out at ...100 or so on the clock ?

No different on the last test thrash then Kev? I was thinking on the way home, when you say it's got 3.89:1 gears, have you counted the ring & pinion or are you going by what the axle's supposed to be from?

It took a little longer than expected

Matt ( Deucetudor) turned up with lots of gauges so we could check everything over . After a lot of playing it still wouldn't idle or atomise fuel properly. Al ( Hemi Bucket) also turned up and we decided to rob the DGAS from the POS. Mark Bull and Nick New also turned up to cover ****taking duties whilst bits were swapped over.

Took it for a drive and torque is definitely up ,lifting the front far more and when letting speed drop in top it will surge forward when accelerating rather than slowly gather speed.

I also took our 135bhp (92kw) DOHC Sapph for a run to compare acceleration characterics as they are of very similar weights .It does look like the gearing ( as suggested by many ) is playing a large part in the brickwall effect as 1st gear on the A is almost 2nd gear on the Sapph > hence by the time I'm in top in the A that's almost equivalent to overdrive top on the 4 speed auto .

Guess the only way to be certain of that is to fit smaller rims as suggested by some to see the change.


Cheers to everone that gave a hand today

Going to take me about an hour to get it all back together afterwards..fingers crossed.


kev, were all waiting with baited breath here, whats the verdict m8 ?.........

Cheers Richard I've just walked in to give my back a chance after setting the cam timing. I'm paranoid and have checked and rechecked 4 times now

Going to take me about an hour to get it all back together afterwards..fingers crossed.

I have a really good carb you can borrow if you need it, can courier it up tomorrow as long as you let me know today.

Rich