TR6 TR6 Camshaft Install - Engine In

[erstearns]

Thinking about replacing the camshaft while waiting on manifolds and triple carb setup. Will have front frame engine compartment brace, radiator etc already pulled to replace timing cover seal.

Can I replace cam while I am at it. I remember another post that mentioned engine had to be jacked up to get the cam to clear the front body opening. Can this be accomplished by merely loosening engine mounts?

Seems simple enough if can be done without pulling the engine but hate to get into it and find out the guts have to come out of the car.

I understand it is somewhat of a challenge to do without also pulling the head but with a fancy magnet tool and several extra hands should be accomplishable (is that a word).

Trying not to fool with an engine that has been rebuilt too much but is it a mistake to replace only the camshaft? I know there may be other issues that pop up but what should I pay attention and look for in this adventure?

Apologies in advance for the long post and too many questions.

 

[bash]

According to the manuals, a camshaft change is do-able with the engine in place. From what I understand, if you use a new camshaft you really need to replace the lifters. The logic (as I understand it) is that the cam and lifter wear together and "fit" each other - if you change the camshaft then the worn shape of the lifter will wreak havoc with your new camshaft. You might be able to remove the lifters with the head still in place, given the right magnet - not sure if they would fit through the holes in the head.

I am glad I pulled the engine, since it is a lot easier to sort out the timing of the new cam (assuming you aren't goign with a stock replacement) with the engine on a stand. My back would be in bad shape if I had spent all that time bent over the front wing!

 

[Guest]

Using a new cam without new lifters is a recipe for disaster. Sounds as though you are going with a high-lift cam, what with the trips and all. You really need to check the old posts on lifters and what is out there.

Remove the head and be done with it. Follow the Bentley manual step-by-step and you will find it not too hard; you do need to be on jack stands so that you can move the steering rack forward to get the timing pulley off. Jacking the engine (and removing the grill) to get the old cam out are a must. With the car on four sturdy jack stands, I used a scissor jack and a length of 2x4 against the front lip of the engine block from below to lift the engine till it bumped the firewall. This will give you just the right amount of clearance for the cam to jump over the grill opening. Short of this, there is no way to get the cam out with the engine in the frame. After the new cam is in place, gently lower the engine (that is why I like a scissor jack, complete control) to reattach the bottom engine mounts. The engine is easily rockable from above to get the bolts to line up for the mounts to be rebolted.

 

[Tinkerman]

If you start to replace one valve component you really need to replace them all. New cam, new cam bearings, new cam, new lifters and yes you have to take the head off to replace the lifters. Do it once and do it right, or don't mess with it until a componnent starts to give you trouble. Of course there is the old adage, "if ain't broke etc., etc."

My thoughts anyhow.

Good Luck, Tinkerman

 

[2wrench]

Tinkerman: Did I miss my cam bearings installation?
Hate to find I did, but best to know about it now.

 

[DrEntropy]

That lump you have doesn't use bearings for the cam unless you have the thing line bored and babbited bearings fitted. Ya ain't missed a thing. :wink:

 

[erstearns]

I have to admit there is merit to not tinkering if it aint broke. If the cam is to be changed then it makes sense to do it with the engine out and pull the head to make all the other necessary changes at the same time.

Guess the logical thing is to make the carb mods, fix the timing seal leak, buff out the scratches and drive.

Engine work, paint and other odds and ends can wait until next winter or whenever. Not like I don't have enough to do already with the BE and 2 in their current state of "apartness".

Good advice, thanks.

 

[Tinkerman]

2Wrench I am working on a tractor engine that has cam bearings, interesting installation. Really don't know about TR6's, Sorry if I misled, :-(
I just checked his profile and sure enough he is working on a 6. Ah well, I do stand behind the basics of my post, though.

Tinkerman

 

[Brosky]

I was at the machine shop today to drop off parts for my TR6 engine. I saw my block come out of the cooking tank and get prepared to start the line boring and boring of the block for cam bearings. Done properly, this is a very slow and tedious process, hence the expense of between $400 & $500 for the labor to install them alone. That does not include the price of the bearings.

I decided to go all out and have mine done. Is it the right decision? For me it was, maybe for another it wouldn't be.

 

[RonMacPherson]

I think it is the right thing to do. Proper bearing surfaces cut down on cam twist....

Too bad you couldn't find a shop that had the old VW/Porsche case lining bore bar. That worked on the first 6 I had back in 87. Only cost me 150 then, but that was a while back, when gas was still only 37 cents a gallon.

 

[vettedog72]

I wish my TR6 would rev fast enough to worry about cam twist :laugh: