Engine idles rough in "Drive" but fine in neutral or park...

[xgecko]

Put them in place and torque them to the spec. The only caveat is that you probably want the cam in a position such that the lifter is on the root of the cam; this is more to make it easy than anything else but it is probably best to do it this way. I know from experience that this is not going to be easy on a high compression motor...

Good luck!

[Twilight Fenrir]

Put them in place and torque them to the spec. The only caveat is that you probably want the cam in a position such that the lifter is on the root of the cam; this is more to make it easy than anything else but it is probably best to do it this way. I know from experience that this is not going to be easy on a high compression motor...

Good luck!

Soo... That's making sure the valves are closed, right?

[xgecko]

Yup. Generally a good idea to ensure a reliable torque reading.

[Twilight Fenrir]

Ahh, it's good to have the forums back...

Anywho, got my parts and tried to put them in. To my chagrine however, there appears to be another issue. The push-rod is recessed into the engine about half an inch too far. It would seem I have a collapsed lifter.

Tried cleaning it, and thwapping it with a mallet per the service manual, but it's still stuck down there. It still rises and falls with the turning of the engine, but it doesn't stick out enough.

After some research, it looks like I can just replace the one lifter, so that's what I'm going to do for the time being. If it becomes necessary to replace the cam and other lifters I will do so at that time. It was also explained to me that by removing the radiator (again >_>) and flopping the AC condensor out of the way, I could remove the cam without having to pull the block

My lifter just shipped, should be here by wednesday, which is also my next day off. Then I'll throw it all back together and see if it works again. And Thursday I'm going to go look at a Fiero with T-Tops

[xgecko]

Where did you se the bit about replacing single lifter? From everything I know this is not viable as the cam has been burnished by the previous lifter and the new lifter will not properly burnish as a result. You are almost certain to wear the cam lobe flat from what I understand.

I will grant that I have only my knowledge as a Mechanical Engineer combined with what I gleaned from research on the net, so please send me your source.

I sure hope it works out for you, but if I am correct you will end up replacing the camshaft in the near future...

[Twilight Fenrir]

I sure hope it works out for you, but if I am correct you will end up replacing the camshaft in the near future...

And, that's entirely possible... but, I'd be replacing the camshaft to avoid replacing the camshaft... so there's not really any harm in it

My "Sources" Were I went to yahoo typed in, "Can I replace just one hydraulic lifter' (or... something to that effect, forgot exact wording) And every single link that actually pertained to it was usually a forum, where it was decided it was acceptable by multiple people... As I understand it...

You can put new lifters on an old camshaft, but you shouldn't use old lifters on a new camshaft. At least, it appears to be the general consensus. Ideally of course, the cam should be replaced for optimum effect, however it shouldn't be detrimental to just replace one, or all lifters.

[xgecko]

Interesting. Google returned many forums that said just the opposite...

This is where my Materials education kicks in and suggests that the lifter will only burnish on a new cam as the cam lobe needs to be slightly rough to begin with; this is borne out by the difference between the cam I removed and the cam I installed. The cam I removed had individual wear patterns on each lobe while the cam I installed had a slightly rough, uniform surface.

You are right, however, to some degree, but frankly you have taken much of the motor apart already. Not sure it is that much more of a big deal to finish the job...

On the other hand, I have developed the philosophy of doing whatever is expedient to allow me to drive my car until October when winter more or less sets in such as it is here in the Pacific Northwest. You might have a similar notion where you can dig deeper in the winter but just want to get back on the road for the rest of the summer. I am very much in favor of this kind of thinking.

Good luck!

[Twilight Fenrir]

Interesting. Google returned many forums that said just the opposite...

This is where my Materials education kicks in and suggests that the lifter will only burnish on a new cam as the cam lobe needs to be slightly rough to begin with; this is borne out by the difference between the cam I removed and the cam I installed. The cam I removed had individual wear patterns on each lobe while the cam I installed had a slightly rough, uniform surface.

You are right, however, to some degree, but frankly you have taken much of the motor apart already. Not sure it is that much more of a big deal to finish the job...

On the other hand, I have developed the philosophy of doing whatever is expedient to allow me to drive my car until October when winter more or less sets in such as it is here in the Pacific Northwest. You might have a similar notion where you can dig deeper in the winter but just want to get back on the road for the rest of the summer. I am very much in favor of this kind of thinking.

Good luck!

Yeah, I'm pretty much looking at the "band-aid till winter" stance

http://www.ehow.com/how_6345330_replace ... lower.html

GM protocol appears to be replacing just the one if they can isolate it:
http://camaroforums.com/forum/ask-gm-10 ... icy-59288/

This one kind of paints the best picture...
http://wiki.answers.com/Q/Do_you_have_t ... .3L_Ranger

[xgecko]

Interesting. I have to say I am still a bit skeptical, but at least I did see this on the first link:

Upon restarting the engine, adjust the idle speed to no less than 2000 RPMs and operate it at that speed for 20 to 30 minutes for flat tappets. This process IS REQUIRED on all new camshaft installations and is suggested for new lifters.

As noted, this most certainly will get you through to Winter almost no matter what. I would definitely schedule a cam replacement, though. An excellent choice for Vacuum Power Brakes is the Mondello JM 18-20 cam which has a 112 degree lobe angle that will support strong vacuum. I have a motor still sitting in a barn back in New England that was built with this cam and it works very well with the Toronado Intake and Exhaust manifolds. Highly recommended for maximum power with minimum fuss...

[Twilight Fenrir]

One thing I was kinda curious about, but don't know because I don't have one in my hands to look at... The service manual sayd the lifters can be dis-assembled... wouldn't it be theoretically possible to replace the innards of the lifter, and use the existing portion that contacts the cam? Thus negating all concerns?

Wednesday, my new lifter should arive, and I'll have my old one out, so I'll take appart the old one and see what I can do.