cam followers

[SvoGreg]

I have a boport stage 3 head not sure spec. on cam but it is a reduced base Circle cam. Over the last year four times the cam followers have fell out. The first time this happened I put new lifters in and since it's happened several times. Any idea's?

[MikeFleming]

Your valve-rocker arm geometry is incorrect.

It's a complicated subject. There are some very good guidelines near the end of Esslinger catalog that you can download in PDF.

[SvoGreg]

I did go through the procedure of shimming the hla's and putting lash caps on the valves to get the geometry correct. I could be off if I did not get all the oil squeezed out of the lifters but the second time the lifters were brand new and had no oil in them when I did it. So I am pretty sure that they are close. The head is on the car and I really did not want to pull it because it's a daily driver and I'm on vacation till next friday, but if I have to I will pull the head and send it to the Machine Shop money is not an object. I can't find much on this subject.

[SvoGreg]

I will recheck it, maybe I was off. Thank you for the help.

[MikeFleming]

I'd say "Bring it by and we'll have a look" then I see Georgia. Kinda a fur piece.

What springs/pressures are you running?

[SvoGreg]

Not sure any of the spec. on cam, or springs, I bought it from someone that just had all the work done. I have been told to shim the springs but not sure if that is the problem.

[SvoGreg]

I took this week off to get the pimp installed but first day off this happened.

[MikeFleming]

Email Bo and ask him what the total valve lift is for the spec cam you have. Then compare that value to the measured TVL with your current ricker arm geometry (using a fixed, zero-lash lifter). This will give us a starting point on what to do next.

[Mike S]

According to Bo's site:

Machine work to the valve guide bosses required with .550" tip length or factory multi groove valves. Aftermarket springs required. RPM range 3500-7000+rpm

[SvoGreg]

I remove the lifters, bled them down, reinstall them and rechecked all the clearances between the cam the followers and I got .030 on every one of them so we'll see what happens.

[SvoGreg]

The tvl is just what it supposed to be.

[MikeFleming]

Same arms come off each time? Or different ones?

Do you have a way to check spring pressure?

[SvoGreg]

No, I have no way to check the spring pressure but everything is new. When the rockers come off it is always in between 2500 and 3000 RPMs at a cruising speed in 5th gear and now I've got it all back together when driving in those RPMs it has what feels like a miss but once you accelerate above 3000 RPMs it runs fine. I think something is wrong in the head. The plugs, wires, cap, rotor, coil, distributor, and module are all brand new and have been replaced 3 times. Money is not a problem on fixing it, This car has been my daily driver for 20 years and I have nothing else to drive to work.

[SvoGreg]

My car is a 1986 SVO Mustang with crowler Sportsman rods,Wiseco forged pistons,windage tray, boport stage 3 head, gutted and Polished upper and lower intake, 65mm t/b, Bob's header, t3t4 Garrett Turbo, gnari front mount innercooler, aluminum flywheel, 3" down pipe, 2 1/2 dual exhaust, 255kph fuel pump, adjustable fuel pressure regulator, and I have a pimp that has not been installed yet and stuff that I probably have forgotten. The car runs incredibly good except in between 2500 and 3000 RPMs. It will absolutely destroy my son is 93 GT.

[MikeFleming]

I think you should email/contact Bo directly. He's very helpful & knowlegable in the 2.3 OHC Ford arena.

[Mike S]

Do you know what springs were installed and the install height? I think for that big of a cam, you would need at least 130 psi seat pressures.

[SvoGreg]

I'm not sure of all the specs, I'll make arrangements to get another car to drive and I'll pull the head and take it to the machine shop.