409 lifter replacement

[GCAMINO]

Ok, here's the story. I rebuilt a 62 409 for my 62 Bel Air. The car originally came with factory A/C. I decided to go with a hydraulic cam. The lifters I installed are Delphi brand, and are floating at higher RPM. There is less than 75 miles on them. The question is can I replace the lifters, without replacing the cam. I have heard this is a bad idea. I remember doing this in the past with no problems. Changing the cam with the engine in the car creates a problem with re-sealing the oil pan without having it leak.

 

[scott hall]

Sounds like a valve spring problem. I’d check the psi closed and open.

 

[GCAMINO]

Brand new matching hydraulic cam and springs from Show Cars

 

[MRHP]

If open and seat pressure were not checked, along with installed height of spring, you will have problems. Springs cannot just be installed without any checking. What rpm are you having issues?

 

[GCAMINO]

Checked and adjusted the spring height, but not the pressure. Under full throttle at about 4000. Tach not hooked up yet. Accelerates fine then dies and starts breaking up. It's like it hit a wall.

 

[wristpin]

Why do you think it's a lifter or spring issue instead of a timing or carb issue?

 

[GCAMINO]

Carbs professionally re-built, removed and checked for float level, and blockage. Tried another distributor, same results. Replaced points and condenser. Timing set at 12 degrees, with advance disconnected. Total advance 33 degrees.

 

[GCAMINO]

At this point I'm trying everything. So back to my original question, is it ok to change out the lifters without changing the cam?

 

[427John]

To answer your question about replacing lifters without replacing the cam if it becomes necessary,that should be no problem as long as the cam has no damaged lobes and they exhibit normal wear,the no no is replacing a cam and using old lifters.If you do replace lifters make sure to get break-in lube on the lobes and bottom of lifters and perform another cam break-in.

 

[GCAMINO]

Thanks for the reply. Like I said, I have replaced lifters alone without changing the cam in the past with no problems. The re-build has only 60 miles, so the cam should be fine.
Got the lube, getting the lifters, and I let you know how everything turns out'
Thanks to all, Gordie

 

[427John]

Gordie,that sounds like a very low rpm for it to be hydraulic lifters causing the problem,try adding another 2-4* initial timing to see if that makes any difference,also if you have another coil available try it and check your voltage to the coil and make sure it matches the requirements of the coil.
P.S. I'd be more concerned that the cam didn't survive break-in than hyd. lifters being the issue.

 

[MRHP]

I hate to be a Debbie Downer, but I have a feeling lifters aren’t the problem. Was the cam degreed? What kind of vacuum does it pull? Cranking compression? For your sake I hope I’m wrong.

 

[chevytaylor]

It could be running out of fuel?

 

[tenxal]

How were the lifters adjusted? The Delphis are great lifters but can be sensitive to the amount of preload.

 

[GCAMINO]

Will check the coil tomorrow. 3/8" gas line from the tank to the pump.

 

[blkblk63ss]

Take a long rubber vacuum hose from carb to vacuum Guage to driver seat ,road test to see what vacuum is doing when it breaks up. Might tell you something.

 

[chevytaylor]

Process of elimination. A suggestion could be to pull the sender out of the tank and check that the sock filter isn't chocked up. Also check and clean out other filters and fuel pump. Is the tank cap vented?

 

[DonSSDD]

Try it on a portable fuel tank to eliminate a fuel feed problem as the issue?

 

[GCAMINO]

I put a milder cam in from SC . Enging idles very nice which makes me believe the cam is ok, Adjusted by 1) turn to tdc 2) turn adjuster down
till pushrod started to drag 3) then 1/2 turn .

 

[GCAMINO]

Pulls hard till 4000.