Hi guys, probably a dumb question but can you replace the camshaft on a flathead engine without having to remove all the valves and lifters etc. Have the engine out on stand with heads removed. Have taken one valve, guide,spring assembly out but as I am sure you know getting those horseshoe clips out of the top is proving to be a real test of patience. I made a tool which seems to be working well to remove the bottom spring retainer. Any advice much appreciated. Cheers Mike.
With the correct valve guide pry par and a long hooked pick tool it is not too big of a deal, the goal is to pull the guides down just enough and the clips should slip right out by getting the hook into the hole thats on the end of the little tab that pokes out. Sometimes you do need to disassemble the valve and spring to get the guides out if they are stuck in their bore. I have been running a set of used Johnson lifters on a new cam since 2007, I feel flatheads can get away with doing this because of the low spring pressures and valve train mass.
You might try this. With the engine on a stand and the timing gear still in place, rotate the engine and stop on cylinders with the valves open. Using a pry bar, lift each valve, and install a wooded clothes pin around the each valve stem. When you have done all 16, turn the engine upside down, and push all the lifters down. That should give you enough clearance to remove the camshaft. On reassembly, pry the valves up and remove the clothes pins. I hope you have Johnsons, the reset the lash.
I helped my brother remove the reground cam that had a bad lobe with the heads on. Don't think the guy at the machine shop [where cam was ground] ever really believed we did it. Cranked all the adjusters into the lifters for max clearance. With a guide removal tool pulled all the retaining clips. Pushed valve/spring assembly up till hit the head, with wire attached to [I think] lifter adj hex pulled lifter up to valve and tied off to what ever handy, pulled cam out. Reversed procedure to put a used stock cam back in and probably put about 30k miles on the car before my sister crashed it [backing up!]. Engine had a little bit of a lope and she used to tell guys it had a Lincoln engine. Scrapped car and 10 yrs later I used it [the engine] in my shoebox for a while and I can't remember it running bad at all; just like a well worn 8ba.
Right on Marty. A lucky few of us were smart enough to listen and pay attention when he would talk. I sure mis that Old Fart. I know he's still with us but sadly no body's home. I'm lucky enough to have 2 Floyd built motors.
What a shame, sounds like a very talented man. Thanks again guys. I am only replacing the cam so that I have one with the gear drive for the distributor for the French flathead front cover and Nash twin eight dizzy for my twin plug heads.
Rumor has it Vic Edelbrock Sr(owner and founder of Edelbrock) wanted to change out the cam in his flathead powered vehicle at the track or Bonneville or someplace but only had a short window to do it in. He said he could do it in 32 minutes—a competitor bet him a case of Scotch he couldn’t—-he actually did it in 29.5 minutes and won the Scotch. Flatheads Forever!!
Hey again Marty, The wooden peg trick worked a treat, thanks again. Like I said I am replacing the original cam with gear drive 8BA style one that I got of a friend and had ground a while ago. Looking at the two cams together the original one I took out has has the aluminium gear on it while the one I had ground (replacement) has the fibre gear. The other thing is that the teeth on the replacement (fibre) go the other way. Can I just bolt the aluminium gear off the original cam onto new one and use it? The other things on the replacement cam is that the cam lobs a quite a bit narrower and also from the bottom of the cam lobe to the top of the cam lobe : original cam 1.463" Replacement (ground one) 1.421". What are your thoughts. The other thing that I will have to do to use the replacement cam is have the bearing journals ground as they are 0.010" larger than the original.
I really can't help with matching the parts up. I had a friend who did all of our flathead work, sadly he passed a couple of years ago, and took all of his knowledge with him.
Sounds to me like the Cam in the motor has had the bearing journals turned and undersized bearings installed to compensate. I believe I'd do just a little homework and verify what standard bearing I.D. is and just change out the bearings. I've never heard of Oversize cam bearings journals. I have run into undersized cam journals. The only time I've heard of reverse rotation drive gears is for Marine applications where the Motor was set up to run in reverse rotation. That is all about the Thrust direction on the Camshaft.
I should have added a big giveaway would be the oil pump drive gear on the back end of the cam. Check them both.
Thanks for that, the oil pump drive gear is the same direction as the original. Will do a little more research as you suggested.
Flathead V8 cam gears, '32-'48 when viewed from the side have the teeth going off (downward) to the right. '49-'53 when viewed from side have teeth that go off (downward) to the left. Obviously, the corresponding crank gear must be used with either.
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