Just completed my new valve seats and valve, installed my new Stipe 280 cam, but noticed when I turned the engine over I was getting this odd bump/clink sound. I listened for a minute and then realized when I touched the end of the cam shaft I could actually feel it. It took a couple minutes but I finally decided that #1 piston and #3 are very barely bumping the cam shaft with the top of the connecting rod bolts.
It wasn't easy to get the engine in exactly the right spot or take good pictures but here is what I got - I think at the moment the bolt is just past the contact point in rotation, but you can feel the cam shaft bump.
Anyway, just want to double check that there's nothing wrong with a little dremel tool action on the heads of the bolts to gain some clearance. It won't take much, but I want to make sure there's enough room that it won't touch even at speed.
Oh, other exciting tid bit for me: I noticed have a nice EE crank!! Never knew that before cause I wasn't looking for it. And while the transmission tail shaft may need to be aligned, it looks like the crank has been ground on some for balancing.
The same thing happened with our 13. I wouldn't hear it until the car was running, then it was a sporadic knock. We finally saw a bit of a shiny spot on a few rod bolts where it was just touching, probably when the engine warmed up.
I noticed some bolts have just a little thicker head and those were just touching, causing an occasional "click". A very little grinding took care of it.
Ross Lilliker put a .280 in a 26 motor for me. He reported no problems and I haven't had any, either.
Seth, lots of T cranks show signs of grinding to various degrees, presumably for balancing purposes. I would never rely on this for perfect balance. Just like the holes drilled in the flywheels for balance, and then add 16 magnets,clamps and bolts!!!
Allan from down under.
When I installed a Stipe 280 cam in my 13 engine, could not rotate the cam completely around. There was not enough clearance between the underside of the tappet and block. I removed the camshaft, spot faced the block removing .040" where each tappet is located. After that, the camshaft rotated freely 360 degrees with no binding between the tappet and block. Grinding a radius may have also worked. I called and talked to Bill Stipe......he had heard of this but it was rare and had only occurred with a few early blocks. Since that time, I have installed another 280 cam in a 13 block and had no clearance problems.
Hey Les, that was the first thing I was thinking when I felt/heard something - maybe I don't have enough clearance for the tappets. I've watched the cam go around several times on each lobe and I have the thickness of a quarter or more between the block and tappets.
I guess the main thing was that I've never heard a sound like this. It's just barely touching, the crank doesn't even stick in the spot. You just hear a clink/bump. Gotta pick up some Ultra Copper on the way home so I can re-install the dip pan and valve covers. I should be about 90% back together after the weekend. Just waiting on the gear guys to tell me about my Bosch Drive unit gears.
Last August we installed a Stipe 280 in a 17 with no interference at all. We used the new adjustable tappets from Langs which were just a bit thinner than the originals. I first tried it with the original non adjustable tappets and it cleared, so I knew that the new ones would clear. We did have to ream the guides in the block for the new tappets which were larger diamater than the originals.
I think the reason some have problems with the fit and others don't is because of aftermarket parts which vary such as the heads of the rod bolts. The bolt heads should be chamfered on the outside of the head and some might be ground just a bit less and so cause the clearance problem.
It's always a good idea when assembling an engine to turn it over before installing in the car so that any problems can be corrected without having to pull the whole engine out. I like to do that when I install the timing gears and again when the pistons and rods are installed. And of course when the flywheel is installed it should be turned several times and the magneto clearances checked between all the various poles and magnets.
I also like to turn the transmission drums before I install the disks to be sure the gears mesh correctly.
could this be an issue with worn cam bearing clearence or even to much rod bearing clearence. Can the rod cap bolt head be beveled to add in clearence?
Cam bearings are not brand spanking new, but pretty new, there's no wiggle room for the cam - Tyrone - I've tried moving it and it's not happening. Same deal with rods - everything is nice and firmly in place and not moving around.
Norman - engine was in car when I started and has stayed in car. I specifically got the Neway valve seat cutting kit because I was loathe to pull the engine again.
I plan on taking a tiny bit off of all of the cam-side rod bolt heads and then making sure I don't have the bump anymore. I'm really excited to see how the car runs with the new cam and valves.
She already runs like a Scalded Dog with the poor valve seats/guides and the worn stock cam. Fresh valves/seats and 280 cam?!? Eliza might go from Scalded Dog status to Scared Rabbit. And of course if I can convince my wife that Eliza NEEDS a Rajo head!! We'd move from Scared Rabbit to a genuine Fire Breathing Dragon. I'd take one of Mark's kits and paint the head black, and then have the valve cover and various chrome Rajo parts brass plated to match the rest of my speedster. Can ya'll even imagine how sexy that would be?
I do not have many good things to say about re-grinds when it comes to pulling hills. Was very impressed on how good the 280 cam performs. The first trip out was over Trail Ridge in Co. Our T did very well compared to others. Before, any Sick model T dragging a dead leg could out run me up a hill leaving me in a trail of smoke. Did a lot of playing with both carb. etc. and it all boiled down to the camshaft.
Update: contact with cam was not the problem. I ground on the connecting rod bolts a little and there was zero change in the sound!
I'm going to check one last time but I've already looked a bunch - I'm confident I have tappet clearance. The sound I'm hearing is because right when the connecting rod is closest to the cam, one of the intake valves has reach max lift. Once the tappet gets on the down slope of the cam the force of the spring is rotating the cam and taking up the little bit of play I have between the crank and cam gear! It's taken a long time but I'm really sure that's the actual problem. Need new timing gears. But that's why I'm getting a bump/clink on every stroke.
I can actually feel it happen by holding on to the timing gear as I crank. I also twisted the gear with my hand so that there would be no play as I cranked it around and that eliminates the sound.
The babbitt on the side of the rods are not stuck!
You can see the seam, like water on wax!