Hi Friends,
I'm not that versed in the DOHC issues even though I've read a ton on here. I'm not a wrencher, but trying. My question is, does anyone know if a Jasper motor build in 2010 would have the butterfly issue or not.

I called Jasper and they haven't a clue.

To observe the serial number, would that require a rigerous disassemble or not?

I'm having a new idle and pulley tensioer installed and contemplating haveing this issue solved during those procedures.

I welcome you input!

Thanks,
Brian

My suspicion is yes it will still have the problem... but remember that's only after 150k+ miles or so.

If you're patient and have a vast assortment of Philips screwdrivers so you can find one that fits the little screws that hold the individual butterfly valves in place, you can remove the plenum, then the screws, one by one. Then Loc-Tite 'em in place.

If anyone wants the dimensions of the bushings used for the pivot arm, I've got them, measured down to the 1,000th or 10,000th, can't remember which, laying around here somewhere, in case you want to have some made. I had a one-off set made out of some unobtanium that a guy who makes parts for NASA made with my brother's help.

John B.

I doubt a Jasper motor includes manifolds. Block, heads, valve covers, and oil pan only, I bet, and you reuse all the other stuff...

Absolutely right! The previous owner drove 14k miles per year. So the new motor only has aprox 45k miles. Not bad but I hate knowing it could fail.

So they typically fail at 150k miles?

Thank you,
Brian <img src="/forums/images/graemlins/kewl.gif" alt="" />

John B,
Do you recommend purchasing the updated plenum? Are their any benefits to the new plenum other than it lasts longer. Like increased power, efficiency etc.?

Or just fix the current plenum and be done with it?

Thanks,
Brian

The old design plenums have shaft bushings that wear out, letting the shaft and butterflies flutter, which eventually breaks the screws on the b'flies and off they go to smash into the valves and pistons, plus the air leak at the bushings leans out the mixture, causing bad idle and emissions problems.

You have three options. One, disco the butterfly actuator and wire it open. Two, repair the bushings, and three, buy a new lower plenum for several hundred bucks.

One loses a tad of power and mileage and is dead cheap. Two fixes the problem, and is tricky and delicate to do. Three fixes the problem and is simpler to install/fix, and has improved bushing material. Depending on the bbushing material used, two may be a superior fix. I'd think the best material would be phosphor bronze. I think the original bushings are plastic. THere are better plastics, too, but p-bronze is self lubricating and hard.

There is a fourth repair, in which you just remove the shaft and b'flies and plug the two end holes, fairly cheap and very sloppy.

The concern I had about the #2 repair listed above was that my measured pieces may not work (closely enough) for others, as the wear could also be in the casting of the plenum, thus rendering the outside diameter of new bushings variable in application. I haven't had a second set made to repair the spare complete piece I was given.

I was thinking Delrin might be a suitable material, FastEddy, what say you? The ones I have in my '95 are an aluminum-bronze-ish alloy.

John B.

Hi John B,
Had to clean the computer cache to log back in on a different computer.
Talked to my mech. and apparently Ford had a similar issue which he's familiar. He has machinists available.

I agree with you that the fix is best when custom, a la a perfect fit.

I keep you posted as to the results.
Thanks,
Brian <img src="/forums/images/graemlins/kewl.gif" alt="" />