Swapped ground afc lever for stock afc lever

[bgilbert]

Pulled my half ground afc lever/foot, installed a stock afc lever. Lost at least 10psi of boost . Previously would peg the 60 lb gauge. Now only 50psi. Fuel screw reinstalled in exact same position. Installed a somewhat ground afc pin/cone gained 2psi. The only other change at this time was, I got rid of the metal afc tube that runs between cylinder head and VE. Replaced it with 1/8 tubing and fittings. Pressure tested to no leaks. Then checked for leaks with engine running and the 'ether test'. Spray starter fluid on all air connections, engine will rev up if leak exists.

Also the truck does not pull near as fast above 2k rpm. To say the least I'm not real happy. Spent the better part of a day fooling with grinding off the epoxy on the roll pin and ball bearings, then pressing it out and pump top R&R. That was mostly my fault as I wasn't sure how to remove the lever. Won't take half as long now to swap.

I think I'm gonna finish grinding the rest of the toe off the afc foot, pull the stock lever and install the ground foot/lever.

Point- seems to be HP to be had from grinding the afc foot if you can get away with or put up with low end smoke.

[boostedve]

now when you say low end smoke is it at an idle or when your on the throttle getting up to road speed. and how much does your pyro change.
and you say your up around 50-55 psi of boost do you have a stud kit or stock headbolts..

[wannadiesel]

Man, I had to put a stocker back in. The gentlest touch would cause a road blocking cloud, the truck was not driveable in traffic.

Can't use the fuel right now anyway, so it doesn't really matter.

[KTA]

Try re-adjusting your fuel screw. Whenever you change the afc relationship like grinding the foot that changes the fuel control collars relative position according to the fuel screw. I know thats not clear, but what it means is you need to turn the screw in some more to get your total fueling back to the same level. Also you can remove the pin that rides against the cone and replace it with a longer one to take more advatage of the afc, then replace the fuel pin with a tapered one with even more offset to get even more travel, then it moves just as far as a cut foot but still has AFV control.

[bgilbert]

now when you say low end smoke is it at an idle or when your on the throttle getting up to road speed. and how much does your pyro change.
and you say your up around 50-55 psi of boost do you have a stud kit or stock headbolts..

Low end smoke is that, low rpm, low speed, little to no boost. Pyro can be hot, but I don't watch it much. Fire rings and 12mm studs.

Also you can remove the pin that rides against the cone and replace it with a longer one to take more advatage of the afc, then replace the fuel pin with a tapered one with even more offset to get even more travel, then it moves just as far as a cut foot but still has AFV control.

Brian you always throw something out there that probly none of us <500hp 1st genners have done lol. Where would I go about finding a pin like that ? Oh and I think I maybe about maxed on fuel screw setting. It doesn't act like a runaway with a snap idle test. It will quickly fall back down. But if you hold the rpm's at 2k, it will start acting like it wants to take off on it's own. I figure I need to make the pump produce more fuel in ways other than turning in the screw.

I don't care about air fuel control, smoke, blocking out intersections etc. I'm just looking to make the most hp with this truck. I'm actually wondering if removing the afc lever completely would make more HP than a ground one...

Last concern after reading a post on tdr about a guy getting a new afc tube, it being a smaller ID than the old tube. Something about it slowing the rate of fueling as the boost rises... I've got 1/8 tubing now with a 1/16pipe x 1/8 pushlok fitting at the afc top and regular ole boost tubing fitting/ferrule at the cylinder head. Maybe I pinched the tubing too much with the ferrule. An easy check will be swapping the old afc tube back in. I'll do that tomorrow.

[KTA]

I used an old needle out of a needle bearing to make my longer pin.

[wannadiesel]

I used an old needle out of a needle bearing to make my longer pin.

Thanks for the tip, Brian. I learned something today.

[Rampower]

How much longer would that needle bearing be KTA?

[KTA]

It is about 3/16" longer than the stock pin.

[mhuppertz]

I need to try the needle trick too. My pin is jammed home with absolutly zero hint of runaway. I assume you just welded it to the tip and ground it down?

[bgilbert]

Well got the 'fully' ground afc lever reinstalled. Along with fully ground afc pin/cone. I bought a set of t-handle ball end allen wrenches, and what a difference. Well worth the price. With the fuel screw back in where it was before, the throttle is very twitchy at high rpm's, say 2k +. Seems to pull hard again, boost is back to normal. Oh I also got rid of the 1/8th tubing I had in place of the metal afc tube. Replaced with 1/4 tubing and high dollar stainless 'swivel' 90* 1/8 elbows , care of buddies shop.

Haven't done any testing, but I bumped the timing up, look for another 425rwhp run lol. I'm thinking about yanking the water to air cooler, then slapping the air to air cooler in for another dyno run on Saturday if I don't do as good as I'd like on Friday.

[dpuckett]

The "runaway attempt" at 2000+ is normal for a hopped up VE- both of my (relatively) hot-rodded pickups have done that.

DP

[Greenleaf]

My 90 wants to run-off @ 2000 rpm's. However when driving the truck, the load on the engine will not allow such an occurance. It only seems to do it in "N" when I slowly apply throttle.

The 92 will run-off however, the fuel screw is backed out PLENTY far enough (w/more power than I can ever utalize) to the point that run-away is nort even in the equation.

The 90 just doesn't seem to exhibit the "power" (for lack of a better term) as the 92 does. It may be the different injectors, (POD's compared to 185's) or the transmission design etc.

[Begle1]

I bought a set of t-handle ball end allen wrenches, and what a difference. Well worth the price. With the fuel screw back in where it was before, the throttle is very twitchy at high rpm's, say 2k +.

HA-HA!

Would these be genuine high quality Bondhus drivers or cheap imitation harbor freight special Bondhus drivers?


My truck does the attempted runaway thing above 1400 RPM. You have to either keep the engine RPM below 1400, or keep a high enough load on it (above ~2000 RPM) to maintain a constant speed with a constant pedal. Otherwise you need to cut back on the pedal because it's giving itself fuel and speeding you faster than you want to go...

[dpuckett]

Yeah, it is an art form driving in traffic at 17-2200rpm. Took me about a week to get it down smoothly.

DP