quote Originally posted by KurtAKX: I spent a considerable amount of time on a flowbench (as did a couple other guys at Roush) and none of us could achieve appreciable gains from port work on an 84-86 (767) casting head. I can say with certainty that what you've picked up is only a few cfm on the intake side and nothing on the exhaust side unless you've removed the restriction at the collector.

I started with a tired fuel pump with 6 psi and loose piston rings. I will tell you the head was opened 1/8" on 1 side and 1/16" on all other sides for the intake and 1/8" on 3 sides for the exhaust side. I went ahead and bit into the big hunk of metal that is there. see below

The intake is now 2" rather than the 1 5/8" to fit the Holley TBI and I eased the transition to the runners.
I also eased the flow in the exhaust this way, see below

I can tell some of this stuff was useful because it really can rev up to 4000 rpm with no real effort. It flows good enough I think. Now if the engine can take a load... well I think it can go WAY more than people prefer to think. As for comparing to a 2.8 V6 60, I'd say no way if the 6 were in top shape but MOST 6ers are just kept so they keep going....Well that was my idea behind the comparison.

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84 2.5L Holley TBI Manual Trans White

Alright, it's been a while but I've been working out a few little bugs. I had to change out the catalytic converter as it was clogged. Also had to re boot the CV joint outers before taking out on the highway. Any way that done and yea man it is WAY better. Before I noticed that my 84 seemed slower than NORMAL cars let alone any sort of performance type. Opening the ports and the performance cam has really revived the engine. I have yet to get a clear at the toll booth to check 0-60 times but before I was getting 12 secs (he says embarrassed) now I figure...9ish. I will likely go back and change out the push rods and rockers as I did not do so in the overhaul reason being I still got a little clatter. It should be a cinch. Oh and the fuel pump was way tired at 6 psi, new one is at 15 with the Holley TBI. So to all you Dukesters out there. Hey, swapping to a 3800 is awesome and recommended but if you want to keep the manual clutter to a minimum the Duke can realize that "sporty commuter" idea.

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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

[This message has been edited by White 84 SE (edited 08-25-2009).]

Wow, I haven't been keeping up with this forum. I've got a white 84 2M4 that I am just completeing the rebuild on. Rebuilt Tranny, bored and rebuilt engine, performance cam from Fiero Store and a list of new items that I've lost track of. No big changes just new to replace old if I was in a spot that made the component easy to replace now. Did away with Catalytic Convertoer, replaced muffler. Went crazy with powder coating. Everything I could fit in the oven for 20 minutes at 400 degrees!
Note: Don't powder coat the crankshaft pilley, at least not where the belts ride in the grooves!! Way slippery! Belt slipping as soon as engine was put above about 2000 RPM!
Anyway, mine is running but still in garage with wheels off. I'm still playing with the timing. What does anybody know about the open loop/closed loop operation thing. Right now she will start right up and run about 1900 RPM for 90 seconds and then die. I'm thinking ECM changes operating modes at that time.
Anyway again, waiting to hear fuel economy records on your build!!

quote Originally posted by Damelectrician: Wow, I haven't been keeping up with this forum. I've got a white 84 2M4 that I am just completeing the rebuild on. Rebuilt Tranny, bored and rebuilt engine, performance cam from Fiero Store and a list of new items that I've lost track of. No big changes just new to replace old if I was in a spot that made the component easy to replace now. Did away with Catalytic Convertoer, replaced muffler. Went crazy with powder coating. Everything I could fit in the oven for 20 minutes at 400 degrees! Note: Don't powder coat the crankshaft pilley, at least not where the belts ride in the grooves!! Way slippery! Belt slipping as soon as engine was put above about 2000 RPM! Anyway, mine is running but still in garage with wheels off. I'm still playing with the timing. What does anybody know about the open loop/closed loop operation thing. Right now she will start right up and run about 1900 RPM for 90 seconds and then die. I'm thinking ECM changes operating modes at that time. Anyway again, waiting to hear fuel economy records on your build!!

WOW you did just about exactly the same as I did. You wont be sorry. My is REAL nice now. Smooth and quiet and with good bite too. Sounds awesone too. I subbed a glass pack for the cat AND the stock muffler. I put in shims over the rockers and that sewing machine sound pretty much wen away. Drive it every day and I love it.

About the gas mileage.....I have no idea.....My odometer went out...lol...havent looked into it. By feel it is better than before. I used to get 24 mixed city driving mostly. Now it has to be more like 27 because I visit the gas station less often.

About your situation. I bet it has more to do with a vacuum leak somewhere. Are you able to get it timed and see the mark? I found that the Haynes orientation was about right and gave a good point to then tweak. The distributer has to be right and the engine a TDC. They have that picture. It's all in the Haynes.
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84 Duke, Holley TBI, Manual Trans 4.10, CompuCam, White

[This message has been edited by White 84 SE (edited 10-07-2009).]