What to do to a 2056 with 2.0 DJet, Help get this motor worked out. Options

[Teknon]

Ok Motorheads,

Senerio:
New 2056, Slightly more aggressive than stock Isky VP-228 cam, ported 5pt heads with '74 2.0 D-Jetronics. Crane xr700 009 dizzy. Burch exhaust through SSI HX'ers

Question:
What would be some tricks and tips to make this engine more efficient. (IMG:style_emoticons/default/cool_shades.gif)

I thought of having the MPS adjusted for a 2056, read that somewhere. Would like to put an oil cooler in most likely.

What else would be things to concider. The engine is in boxes ready to assemble.

Please chime in

Joe D

[jk76.914]

I'm running an Isky 229 with D-Jet. Though there isn't much overlap (12 degrees at .050" lift, just like your VP228), I saw a significant reduction in vacuum at idle, though my idle was still pretty smooth and quiet. I experimented with advancing the timing at idle, and it improved significantly, which makes sense if overlap is indeed the issue. I'm in the process of modifying a spare distributor to reduce the total centrifugal advance, so I can run more advance at idle but not exceed 32 degrees (plus or minus) total at 3500 RPM. I'll know later this season.

The second thing I noticed was a lean miss at about 3000-3500 RPM at part throttle cruise. I "fixed" it by installing slightly higher flowing injectors, but I think the real solution (not proven yet!) is to tweak the MPS for richer running. Trouble is, I'm convincing myself that the problem is that the diaphram transitions off the part throttle stop too late, because if I open the throttle more (reducing the vacuum, and thereby starting the transition) the miss goes away. Unfortunately, this isn't one of the adjustments available. I hope to get a better handle on this this season as well.... There have been a number of posts from other folks having this problem as well......

I have no regrets in going with Isky.

Good luck with the engine... Jim

[Teknon]

I'm running an Isky 229 with D-Jet. Though there isn't much overlap (12 degrees at .050" lift, just like your VP228), I saw a significant reduction in vacuum at idle, though my idle was still pretty smooth and quiet. I experimented with advancing the timing at idle, and it improved significantly, which makes sense if overlap is indeed the issue. I'm in the process of modifying a spare distributor to reduce the total centrifugal advance, so I can run more advance at idle but not exceed 32 degrees (plus or minus) total at 3500 RPM. I'll know later this season.

The second thing I noticed was a lean miss at about 3000-3500 RPM at part throttle cruise. I "fixed" it by installing slightly higher flowing injectors, but I think the real solution (not proven yet!) is to tweak the MPS for richer running. Trouble is, I'm convincing myself that the problem is that the diaphram transitions off the part throttle stop too late, because if I open the throttle more (reducing the vacuum, and thereby starting the transition) the miss goes away. Unfortunately, this isn't one of the adjustments available. I hope to get a better handle on this this season as well.... There have been a number of posts from other folks having this problem as well......

I have no regrets in going with Isky.

Good luck with the engine... Jim

Wow Jim, Your the man. I've got to study up on all you said. It's over my head right now, but I'm gunna learn that stuff. Mind if I pick your brain in time? Joe (IMG:style_emoticons/default/boldblue.gif)

[jk76.914]

I'm running an Isky 229 with D-Jet. Though there isn't much overlap (12 degrees at .050" lift, just like your VP228), I saw a significant reduction in vacuum at idle, though my idle was still pretty smooth and quiet. I experimented with advancing the timing at idle, and it improved significantly, which makes sense if overlap is indeed the issue. I'm in the process of modifying a spare distributor to reduce the total centrifugal advance, so I can run more advance at idle but not exceed 32 degrees (plus or minus) total at 3500 RPM. I'll know later this season.

The second thing I noticed was a lean miss at about 3000-3500 RPM at part throttle cruise. I "fixed" it by installing slightly higher flowing injectors, but I think the real solution (not proven yet!) is to tweak the MPS for richer running. Trouble is, I'm convincing myself that the problem is that the diaphram transitions off the part throttle stop too late, because if I open the throttle more (reducing the vacuum, and thereby starting the transition) the miss goes away. Unfortunately, this isn't one of the adjustments available. I hope to get a better handle on this this season as well.... There have been a number of posts from other folks having this problem as well......

I have no regrets in going with Isky.

Good luck with the engine... Jim

Wow Jim, Your the man. I've got to study up on all you said. It's over my head right now, but I'm gunna learn that stuff. Mind if I pick your brain in time? Joe (IMG:style_emoticons/default/boldblue.gif)

Sure, but it'll be a two-way exchange. I'm still putting some of this together in my own head, so I'll look forward to learning from what you're doing.

You see, I'm just a humble 914 hobbiest. I don't have all the answers, but I'm a fast learner, a pretty good engineer, and I'm not stupid. I'll warn you though- some of my ideas go against the accepted conventions around here! Makes it fun!