cam change in the car

[chuck stevens]

Anyone have short cuts and tips for in the car cam removal. It's 8BA in a 49 coupe, thanks Chuck.

[Bored&Stroked]

There really are not many short cuts and truth be told, you'll find it actually easier to remove the engine and put it on an engine stand.

On most OHV engines, no problem - on a flathead, it is too difficult (especially on a full-fendered later coupe) to lean over everything, pull the heads and get to the valves. Also, visibility is not good - hard to see what you're doing, easy to drop something into the bowels of the engine, etc.. It only takes a few hours to pull the engine - you will make that up in spades if you do.

Last recommendation is to make sure you put new or newly resurfaced liflters in the engine.

Best of luck - let us know what approach you take.

B&S

[Ol' Ron]

What cam are you using? A hi lift cam will be hard to adjust valve clearance, especially considering the lifter bore are not drilled. This is a difficult job on an engine stand.

[Brian]

I recently changed the cam in my 35 without removing the heads....
Removed hood, grill, radiator and front timing cover.
Removed intake manifold.
Removed all 16 horseshoe clips.
Pushed all 16 valve assemblies up as far as they'd go.
Using soft, ductile wire, I 'tied' all [adjustable] lifters up as high as they'd go.
I used two lengths of 5/16" UNC threaded rod, and screwed them into the bottom two holes that retain front cover.
Turned up two pieces of nylon rod [could use anything] with 5/16 clearance bore, and 1 7/8 od, and slipped them over the threaded rods. Use these to rest the camgear on as you remove cam, they support the end of the camshaft and help alignment during the removal and installation of substitute camshaft. Be careful removing and installing cams, and check journal diameters are the same.

[40cpe]

Originally Posted by Brian

I 'tied' all [adjustable] lifters up as high as they'd go.

Brian, I know you aren't a novice at flatheads. What is your opinion of the recommendation to put new or resurfaced lifters when changing cams? I realize it is the safest thing to do and don't disagree with B&B, but what are the chances of destroying the cam with worn lifters?

[Brian]

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I too agree that B&S gave correct information, but I've never destroyed a cam by using used lifters on it. I am not recommending you do so, just my experience...

[Bored&Stroked]

Some things to ponder - how long ago was the engine rebuilt - do you know? Can the guides be easily moved . . . or do they have many miles of carbon to sort of "cement" them in (exhausts in particular)? Also, what condition are the valves/seats actually in? Have you done a compression check before starting down this path . . . to know what you have and your associated options/plans as such?

Also, what type of valves are in it? Stock valves have a "shoulder" that stops against the guide top - so by moving the guides "up", you can raise the valve. However, if your valves are modern replacements (think Chevy 1.6"), then they don't have this shoulder and moving the guide won't help.

Another question is what type of lifters? If they're stock (non-adjustable), then your whole plan isn't going to work anyway. If they're adjustable, then you'll need to check the bottoms of them to see how much wear is involved - they should be flat at the least and potentially a bit convex (if really new). You can't do this without pulling the heads.

Another consideration is what valve lift did you have in the current cam versus the new one? If the lift is substantially more on the new one, then how much valve-to-head clearance will you have with the new cam? If it is a high performance cam - you need to know that you'll have the necessary clearance above the valves (such that they don't hit the heads).

Assuming Adjustable Lifters in Fine Shape: One idea is to see if Brian's approach will work for you . . . if it does . . . cool . . . if not, then you can go to the 'Plan B' - pulling the heads and all that jazz. You can then decide whether or not you want to tackle any/all of this with the engine in the car.

Used Lifters - New Cam: Nobody can know if this will work . . . or result in a fast wearing cam that goes flat. This is especially true if you don't know the condition of ALL the bottoms. Maybe 15 are good . . . and the 16th is quite worn and maybe it hasn't been rotating and has an ugly bottom on it. If so, there goes your new cam . . .

On my 32, I can pull the engine/trans in about 2 hours (including draining the radiator and removing it - along with front lights, etc). While this takes time (and the necessary tools), it allows me to much more easily work on the engine (as it is on a stand). Also, I can do things like check cam timing and all those things (as I don't use stock cams). If this is a stock cam to stock cam replacement situation, this is not as much of a concern - if it is a stock cam to performance cam situation, then I'm more concerned about all these things.

Best of luck!
B&S

[Brian]

All Dale's advise above is correct; in my case it was a fairly new build; less that 5000 miles on it, and I changed out a performance cam for a stock item. In this particular case, I was merely trying to avoid having to replace head gaskets [the Scotsman in me!].
It would certainly be prudent to pull heads and remove/inspect all the valve related components, the point I was trying to make is that, yes, the cam can be replaced in situ, and was trying to give some pointers in answering the original posters question.

[Bored&Stroked]

Originally Posted by Brian

All Dale's advise above is correct; in my case it was a fairly new build; less that 5000 miles on it, and I changed out a performance cam for a stock item. In this particular case, I was merely trying to avoid having to replace head gaskets [the Scotsman in me!].
It would certainly be prudent to pull heads and remove/inspect all the valve related components, the point I was trying to make is that, yes, the cam can be replaced in situ, and was trying to give some pointers in answering the original posters question.

Brian and I are on the same page . . . we're both a bit too involved in these dang engines and we share as much info as possible. I respect his method - it makes total sense for certain situations, maybe not in others. The good news is that between what we've both shared, you have enough information to make your own educated decision - that is what we're all about here on the Barn!

Brian: Hopefully one day we meet up!

[JM 35 Sedan]

Great coverage by both B&S and Brian on the original question by Chuck Stevens. You can tell these two guys have been around the block a few times, working on these Flatheads.

[40cpe]

I appreciate the comments and shared experience. Thanks to Brian and B&S