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Discussion Starter #1 (Edited)
VVT support bushing failure will be a problem that every late model spider owner will some day face. The VVT solenoid and support is found on all spiders from around 86 on. I don't know exactly when they went with the electronic plunger control....but you'll recognize this setup as a device mounted on the cam cover above the distributor. This bushing is responsible for aligning the solenoid to the VVT plunger. The problem is that the solenoid is held in place by a rubber core bushing that will ultimately fail. So the task will be finding a way to position the solenoid to activate the plunger once this bushing fails. As with a growing list of parts, last time I checked for a new support or bushing they were of course NLA.

Note the pictures of the bushing design. The bushing is a press in type with an outer aluminum shell that presses into the support, a middle rubber portion, and an inner aluminum threaded portion that allows the solenoid to screw in and out to adjust. I don't know why they used a rubber cored bushing rather than a solid bushing. Perhaps to limit engine heat or engine vibration transfer to the windings of the electromagnetic VVT solenoid...but this is just speculation.

My support bushing failed last year while I was installing the polished valve cover on the 92. In the process of backing off the locking nut that keeps the solenoid from rotating in the threaded aluminum inner sleeve of the bushing, I managed to twist and disintegrate the middle rubber core. At the time I managed to effectively repair my mount and bushing by utilizing the original aluminum portions of the bushing, but replacing the middle rubber portion of bushing with a rubbery foam tape that was initially intended for marine use to mount lexan windows to a boat. This repair has proven effective to date and as good as original. But I have always wanted a better than original solution that would permanently and forever repair this problem.

Duke58 here on the Alfabb not so long ago did the same thing to his VVT bushing, shredding it during adjusting the solenoid to spec. Dam lock nut! Anyway, Duke came up with an excellent solution. He has manufactured a solid brass bushing that presses into the support. The brass bushing has the proper threading to match the solenoid. When Duke mentioned he was going to make one...I of course chimed in requesting Duke make me one too and tell me how much he would charge. Duke though sent me a perfect bushing and very detailed step by step instructions and writeup on how to install all free of charge. Wouldn't let me pay. I'll let Duke post up those instructions if he wants to share them as they are excellent. But I just wanted to brag a bit on Duke and others on the Alfabb and in the Alfa community like him that will always help other fellow alfisti with no agenda in mind and looking for nothing in return. So a big thanks goes to Duke. With that in mind.....

Big thanks to Bud (my SCCA nemesis, Little Italian here on the Alfabb) as well for helping me press out the old bushing and install the new "Duke58" brass bushing. I took several pictures to share. You don't have to use a press to install....but the press sure made it a piece of cake. The brass unit was a perfect fit. Very nice piece that will keep the car going.

My advice to Duke....make them and sell them to IAP and Centerline. And my advice to the late model spider owners.....if you plan on keeping your car, you had better get one too!:D

Best Regards,
John M
 

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What about heat.

Thanks for the info John. My concern with this solution - but not a big concern because I quit using the VVT - is the transfer of heat thru the brass bushing from the hot cam cover? Won't the solenoid coil be fried? Can the solenoid stand the heat? Let me know how yours work before I change mine. Are the original equipment bushings no
longer available? I wonder if the same size bushing could be machined out of a piece of Delrin to the same effect but without the heat transfer.:D
 

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Discussion Starter #4
I believe that Duke has been using his for a couple of months now without incident. So.....I would assume....I know, I know....A$$ out of U and ME....that the heat transfer concern or vibrational concern will be unfounded in the long run. And it certainly is in the short term. And AFAIK....the OE bushing is NLA. Don't know about Delrin. What the heck is that Budsy? Something you plan on smearing on your ringer tires to make them sticky again.:D Pain train coming your way ole pal. I have your number here in a few weeks!!!!:D :D :D :D

Best Regards,
John M
 

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Discussion Starter #5
msiert said:
Hey Murray:

In regards to saying Hi to Budsy....be careful and remember.....




Pain train cometh!!!!!:D :D :D :D

Best Regards,
John M
 

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Discussion Starter #6
msiert said:
I was just trying to be nice, he hasn't responded back to me sense I said; he would be following me like a three legged puppy at the track? :D
ROFLMAO!!!!:D

I know....he is all distraught about my "ringer" hoosiers! I have been telling him that the "Pain Train" is coming. His way of dealing with his impending demise is to run to George and ask for some lessons!!!!:D :D :D He is going down in less than two weeks from now! You should come out and beat up on him too! It'll be BIG FUN!!!!:D

Best Regards,
John M
 

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John, again we are indebted to your input and thoroughness in presenting the information. Thanks :)

Have you ever thought of putting together a Spider Bedside Reader with all these helpful ideas?:eek:
 

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Discussion Starter #9
Yeah Murray.....ole Budsy is SOL come this next SCCA event!!!!:D :D :D I can't wait to smoke him!!!!:D Apparently he is so afraid that he won't even defend himself!:D

Hey Lenn:

I could write one but it would be too full of BS and too empty of fact. But every once in awhile I get something useful out from in between my ears!:D Big kudos go to Duke on that brass bushing. It is production quality. I must admit the solid metal mount and the polishing possibilities are right up my alley.:D

Hey Mike:

I remember reading that a long time ago about you doing that but couldn't find the post when mine shredded. Now you tell me!:D After spending a bunch of time at autozone comparing hoses to the mount...I gave up as I couldn't find one to fit. I resorted to my trusty friend, the roll of the fancy...and expensive...tape left over from where I remounted my cabin cruiser's lexan windows.:D

Best Regards,
John M
 

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It turns out that I mis-spelled "rebuilt" as "rebult" in my post. That's probably why it didn't show up in the search. I'll edit it and fix that. When I searched for it, I used
"VVT bushing radiator"
as the keywords because I remembered using radiator hose. If I'd searched for "coolant" instead of radiator, it probably wouldn't have succeeded. Sorry for the keyword issue. I suspect yours will still work in 2 yrs, too. I have enough hose to last me for 40 yrs at 1 rebuild per decade.

Michael

[edit: strange thing -- for me, anyway, the search succeeds if and only if I search keyed to my 'MrT' name. If I search for 'VVT bushing rebuild' or 'VVT bushing repair' without the 'MrT' in the author box, it doesn't pick up on the search. --Simon?????]
 

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Hi All!

Thanks for the great write-up John M!

My initial concern with using a brass bushing was the heat transfer issue. I posted the question here, but did not get a single answer.

Knowing that solenoids can and are designed to withstand heat/vibration, I assumed the Italian engineers had the forethought to specify a solenoid thus configured.

I have at least 1000 mostly highway miles on the new bushing and know the VVT still works. I learned that the VVT was not working for the 2 previous years I had the car. This is because I can now feel the engine pulling up to red line. It is a definite and distinct difference in performance. I found that the VVT was ****ed to one side by the wear pattern on the solenoid itself.

All that said- I have also found other solenoids that will work should this one fail. I will have to machine a different bushing if it ever comes to that point.

The rubber mounting is a poor design for such a perfomance enhancing feature of the car.

Thanks again to this BB and John M.

Duke
 

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There might be reasons for the rubber bushing (apart from "that's just how we make bushings"). First is probably cost. Thin steel pieces like the threaded liner joined to the solenoid housing with injectable rubber might be relatively cheaper than a thicker metal machined piece. I'm not a manufacturing engineer, so I do not _know_ the relative costs. That they _did_ specify that relatively large aluminum housing argues more for force of habit than any hard cost reason.

Vibration isolation comes to mind, but must be totally unimportant as the starter motor is not an item known to fail from vibration. More likely to be relevant would be the weight of a metal mount and the added stress on the mounting screws attached to the aluminum valve cover. But maybe the killer reason was that the bushing was part of the existing design of the solenoid? I don't know.

We might consider what the thing actually does: it presses a button and lets oil flow somewhere. No proportional control, no partial engagement. Just on/off. Why would anything matter other than whether the throw is significantly larger than the clearance of the plunger from the button? I can't see any reason for a metal mount other than the "does it last forever instead of just 10 yrs?" question that a long-term afficionado would ask.

I personally would continue rebuilding the rubber bushing once every decade or two, using radiator hose and black RTV, unless I had a lathe handy and had a chunk of pipe or bulk material that I didn't have other plans for. Brass, aluminum, certain plastics, etc.
 

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Mr. T,

(I pity the foo.)

All good points. I asked the same right here on this BB. Got no answers.

Delrin or some other type plastics was considered as an option. (I have two made if msiert wants them. PM me and I'll send them).

It just so happens that I have a lathe laying around, worked as a journeyman machinist for 12 years, including paying my way through college as a machinist. My other hobby is Live Steam locomotives- I'm making a Shay locomotive. I've been an engineer since 1992 when I graduated from college.

Rebuilding with rubber did not seem a viable choice. The old rubber mount disintegrated when I tried to adjust it. No one on this BB knew why it was mounted in rubber. With such a small diameter of rubber, I can't see how it could appreciably isolate the solenoid from vibration/heat. I don't think a solid mount will result in thread failure of the mount itself.

A piece of brass costs around $12. My labor was free. Considering that I drove around for two years without the VVT working properly, it seems a small risk to use the bushing.
 

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I just rebuilt my wife's small-end dogbone mount tonight. It had failed and _all_ of the rubber was gone. I did the radiator hose trick (the material is _just_ the right thickness) and put it together again with Permatex Ultra-Black RTV as assembly lubricant to do dual duty as glue after it cures. It had worked find for nearly 3 years on my daughter's '93 164L and I expect it to work similarly well and long on this '91 164L.

It looks like the engineering options are wide. I learned machinist skills at an amateur level as a physics graduate student at Berkeley. The powers that be thought that an experimental physicist ought to be able to fabricate some of his own equipment, in a pinch. I'm grateful for the mechanical experience.

Michael
 

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Its been at least 3 months since installing the brass VVT mount bushing.

She's still going strong. I'm still driving the car everyday and making my once a month 600+ mile round trip between Amarillo and Albaturkey. I checked the solenoid yesterday-still working.

I'm thinking of learning Italian so I can contact the ALFA engineers to ask why they mounted the VVT in rubber... AIDS maybe?
Ha!

Duke the engineer. (former Marine Corps electronics warfare system tech. We jam harder, penetrate deeper and dispense in all modes of operation)
 

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Just for giggles, next time you check your valve lash, inspect the cam plunger and the tip on the cam VVT proper to see if there's any sign of wear.

The only 'downside' I could see to your system would be if someone got the solinoid set a bit deep and it made the plunger and or tip run against each other with a bit more pressure than neccisary, or outright bottom out. (ie: you wouldn't want it to press hard enough to drag, which the rubber may or may not allow a bit of)
 

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My VVT was totally rotten, and not engaging. I did the old radiator hose repair a year or so ago, and it's still working great.
 

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Four years and 60,000 miles later-

The VVT still operates with the brass bushing. No mess, no fuss.

Fix your VVT with radiator hose or a bushing, make your choice.

Duke
 

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VVT Bushing

Duke:
My VVT is suspected to be the culprit in my 86 Grads not starting. While everyone says to remove the VVT entirely, as it is not needed, the purist in me whispers that it must have been put there for a reason.

I did a search and found the several years old thread on your brass bushing. Please give me an update: is your brass bushing still performing well and would you still recommend going that route?

Do you have any drawings/pictures that might help in making my own bushing? It seems like something that I could easily turn over to a machinist to make.

Any suggestions/comments would be MOST appreciated.

Many thanks in advance for your time and efforts,
Dean Mandlebaum
 

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No vibration issues for the solenoid from the solid mounting? I'd guess not, as starter solenoids aren't mounted in rubber.
Andrew
 
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