I'm askin' Santa for a good December Banger Meet

My anti-walk timing cover.

Same out come as the others just achieved by different means.







The cam is constantly moving forward in the block due to the helical cut gears. The more revs from the engine the harder it pushes against the plunger. The cam will change position depending on the revs and as the ignition is run off the cam your ignition timing changes as well.
The idea of the fixed stop is to keep the cam in a constant position thus keeping the ignition timing fixed as well.

 

Thanks for the info guys I really appreciate it!!!

 

on my T motor, I used straight cut gears. Lots of guys don't like them for what ever reason. But they work great as they allow the crank to expand and contract as revs +/- with out binding on the cam.

 

All this talk about cam walk has me wondering about my flimsy tin timing cover on the Chevy... anybody know if someone makes a cast cover for the '26-'28 Chevrolet 4?

 

Never heard of this reason before for the use of straight cut timing gears.

I just fitted them for the noise.

 

that was my original reason ...then i learned that there is this added benefit...as a note this was a stock T crank being used...that i was routinely running over 3k rpm on

 

I used straight cut gears on mine specifically to halt cam walk, the noise was a bonus, but even that has faded a little. Brilliant gears though. Got them from Dan McEachern. The other benefit with the straight cut is that there are 66 teeth on them as opposed to 50 on the helical gears, meaning you can get your cam to crank timing much closer.

I've got a timing cover with a Torrington bearing on my other banger.

 

Straight cut timing gears on their own won't stop cam walk as the dizzy drive gears are still helical.

I done alot of messing around with mine and even though I've got straight cut gears I found as soon as that engine starts turning the cam is hard up against the stop.

 

HI Folks

I come from sweden and have a stock tudor.I am hoping up a new engine for it,I work on the crank right now and ask you folks for device. What weldingrod should I use when I welding the weight on the crank?. Hope you understand my bad english.

Rickard

 

Well, let me tell you a story about cam walk. When I built the Winfield flathead I put in a set of REM billet Al. rods. When I drained the oil after a few hard runs I found fine Al. chips in the oil. When I dropped the pan I found the cam lobes had hit the billet rods and cut into them. So I made my first cam stop. Some people just measure and put a solid plug or spacer in place of the spring. I didn't like that idea but I guess it works.

 

Was that with helical or straight gears, Bill?

My reasoning was that it is the crank that drives the cam (yeah, I know, obviously...) and the helical drive from the crank that drove the cam forward. I didn't see that the dizzy shaft would force the cam to move in any way near the same amount (always willing to be proved wrong, I hasten to add!).

 

Helical, I don't know if the cam crankgear combination drives it forward or not the thrust portion is on the rear of the cam gear boss, but I believe there is a problem with higher loads from high pressure oil pumps. I don't think the cam/crank combination would necessarily drive the cam forward as most helical gears are one directional. I base this on years of experience with spindle speed change gears on automatic screw machines. The older machines used spur gears and the helical gears were marked as to direction. If reversed they tended to accelerate thrust wear on the shafts. There have been comments in the past regarding the extra force required to drive some vertical magneto's causing wear. But my experience did not find this as I have the cam (reground) that I ran in my daily driver in the 50's 60's with a Wico magneto now in my current Winfield flat head. But I must say that the cam had chrome plated bearing surfaces and maybe some chrome migrated to sides of the oil pump drive gear.

 

I've been thinking about this cam walk thing all day. I need to get all the parts together and work this out. Until I do, I think the direction of the angle cut on the timing gears would force the cam back against the thrust surface of the block. My theory is that when you convert the oiling system to Pressure it creates more drag on the oil pump. That extra force on the cam to drive the increased resistance of a pressurized oil pump forces the cam forward. Maybee through the helical oil pump drive or from hydraulic pressure created between the back of the rear cam bearing and the flywheel cover. Food for thought.

Has anyone had cam walk issues on a stock, non pressurized engine?

.

 

Bill, The tin cover is fine, the cam on Chevs are retained by a 1/8" steel flange that bolts to the front plate on the block.

 

The guy that makes the needle or roller bearing cam stop or thrust control is
Stan Vermeil
Vermeil VEO Products
530 432 2881
he also make the Al. front seal carrier. He does the thrust on an exchange basis.

 

Inserts!!

While I'm at it there has been a thread on Ford Barn regarding the 1 piece insert (by 1 piece I mean there are just 2 halves or shells instead of 2 side by side) The ones furnished by the firm with their rods have no copper underlay just Tin over steel and he states no problems with engines up to 8 to 1 and no more than 28 degrees max advance. Max Sr. stated that his 1 piece have the copper plating but not sure if his are interchangeably with the others. The poster on Ford Barn said after a long trip and pulling some long hills he noticed a drop in oil pressure. He had 17,000 miles on the engine and had 31 degrees advance.

 

Jim,

You would think that I would remember since I just tore down the spare engine, now wouldn't you...

Is there a distinguishable benefit to using the '25 block since the cam isn't running the distributor? And does anyone make a better cam gear than the stock fiber one?

Thanks again, Bill

 

Thanks for all the gearing and drive info, everyone. I`m not at all sure which trans I have, will look in the archive for all the info, then drag it out and check. Seems like a .69 may be the way to go. Back to my cracked block pile--Two now, two more left to check, hope the late 31 block is the good one...

 

Thanks for the info and input guys I really appreciate it.
I am looking for the part # for the lifters with the larger Dia. head. I don't wont to order the wrong ones . Did they come from a dodge 6 ?

CDO... do you know the weight of the H&H rods you used

anti-walk timing cover... looks like H&H uses the torrington bearing set up for a small block chevy

Enbloc... is it a good noise???? (I just fitted them for the noise.)

For you guys running bigger valves are you running on the block or a seat?

thanks Bill

 

my theory on cam walk. rapid rpm increase and decrease would make it walk to opposite ends (more so with helical cam and crank gear setup) and contant rpm would be one end. without looking at pics...rpm increase and constant would make cam walk forward and rapid rpm decrease would make it walk backwards.

this is just my thinking out loud. i think i will drill a hole in my timing cover and put a dial indicator in and check it! we shall have an answer! will take a few days as i am out of town again.

bill, cdo...someone put an indicator on it and see what you get.

 

Helical gears move in one direction. I think that as Ford developed the "A" engine they must have taken this into consideration. This is why, if you study it, you will see that the direction of concern was to the rear thus the large diameter boss cast in the block and the large mating diameter hub on the cam. Their concern with forward movement is shown by the use of just a spring to control the forward movement of the cam.

 

Intakes in the block, exhaust on seats. I just use the single lock lifters/camfollowers. The chrysler type requires modification to use. Any way that is what I have recently read in S O S S. and others in the past. I think they are taller. There was an article where, for some reason, the builder of a 2 port only used them on the exhaust or just on the intake. He stated he reamed the block to fit. He also stated the source.

 

CHRYSLER LIFTERS

I had thought to just edit my last post with this information but will now post the information separately.
In the S O S S Volume 18 #4 April 2009 on page 32 starts an article of a build of a C Yapp Riley 2 port, on page 36 the builder describes his valve train. Chrysler 6 cylinder lifters/cam followers are used on the exhaust. "B" single lock on the intake.
His source was
Terrill Machine Inc.
1000 county road 454
DeLeon TX 76444
254 893 2610.

He states that the lifters are adjustable and are .345 taller than the "A" "B" and the lifter base is 1.292 the lifter body diameter is .625 so he reamed the lifter bosses.

 

It was when I first fitted them . They had this fantastic supercharger whine. That slowly disappeared and now they are just noisy.

I've thought about changing them back to Helical. I wouldn't fit them to a road engine again.

 

Thanks Bill & Enbloc
I am still up in the air on stoke or not to stroke the engine. My crank is mint but more cubes more power.
later Bill

 

I think the crank is steel not cast so just weld it with any rod. You will have so much weld and 2 bolts it wont go anywhere. But I have not welded weight on a crank my self yet so I could be wrong

Anyone got 2 cent to add I think Its a good question. When you weld does the heat make the crank move (bend) ?

 

Great thread. I have a couple of A cranks that I need to drill for oil pressure. It has been a long time since I have drilled one, and have lost the information showing the angles of the holes and also the starting points on the journals. I still have a crank that I broke through the corner of the journal while drilling. I don't need to repeat that experience. Thanks for any info.

 

Wayne, I know the angles etc are in one of the SOSS mags. Not sure which one I can do a search later and get back to you. Also the older guy with me at the meet in Northwood has done them. Great meet by the way.

 

Mine were very whiny to begin with, too much so in fact, but I can barely hear them now.

 

I am in the process of mounting a 27 t body on a 28 stock chassis and running gear. With the body lined up with the wheelwells, I have a small interference with the clutch pedal and the firewall. Has eneyone encounterd this problem,and what did you to solve it. thank you