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With the numbers of cam/lifter failures on new installations, I'd be very leery replacing a known good cam. I'd even try to save that one lifter. .02 cents
With the numbers of cam/lifter failures on new installations, I'd be very leery replacing a known good cam. I'd even try to save that one lifter. .02 cents
Years ago, I had a push rod break on my 265. Had a 097 cam in it. Very few miles on the cam/lifters. When I pulled the push rod, I saw the seat had popped out of the lifter. Chevy solids back then didn't use a snap ring to hold the seat in. Being young and dumb, i thought the lifter was trashed even though the cam side looked good but I wanted to be safe, spent less than a buck and I bought a new one.
Put the engine back together, fired it up and within a couple of minutes, I had a rounded lobe on the cam. Same lobe that had the new lifter on it.
Did I mention that I could have popped the seat back in the lifter and been okay with it? Did I mention the push rod broke first and that let oil pressure shove the seat out of the lifter?
With the numbers of cam/lifter failures on new installations, I'd be very leery replacing a known good cam. I'd even try to save that one lifter. .02 cents
Jim,
I'm not as optimistic as you regarding simply replacing the offending lifter. I spoke with several "known" engine builders when we tore this thing down, and I mentioned simply replacing the bad lifter...to a man they said they would never do it. The odds of wiping out a cam lobe with a new lifter are apparently pretty high. While it was this far torn down, it was a rather easy decision to replace the cam, timing chain and gears, lifters, etc. With any luck, she should be back on the road by the end of this week. I've been having a devil of a time posting pictures recently...I'd like to try to post some more progress shots.
P.S. Just tried to post pics...no luck!!
Last edited by leif.anderson93; 05-06-2019 at 06:31 PM.
I don't see an issue with installing new lifters for a variety of reasons. Just make sure a break in procedure is followed with the new lifter just like you do with a new engine start up.
Many engines have had a lifter fail, mechanics replace that one noisy lifter and move on. A break in of 20 minutes running 1,500 to 2,500 RPM is mandatory but that is all.
Personally I vary the RPM but always keep it higher than 1,500. This has to be done immediately on start up. As soon as you verify you have good oil pressure and no stange noises crank it up and keep it up.
You will need help because on a break in the trottle needs to stay at the proper RPM but you also need to have someone crawling around looking for oil or coolant leaks and watching temperatures and oil pressures for the full 20 minutes.
You may have to run fans or mist cooling water to keep the engine at the RPM while parked and not have an overheat. Be prepared and all will go well.
To me the odds are identical, breaking in a new cam and lifters or the old cam with one new lifter. Two more cents for you. Hey your almost up to a nickel worth now.
I hope you have it running again soon.
Mark
I have installed all new lifters on an old cam. No issues. Just use plenty of cam break in compound on the lifter faces and run it in as Westlotorm advises.
I'm not as optimistic as you regarding simply replacing the offending lifter. I spoke with several "known" engine builders when we tore this thing down, and I mentioned simply replacing the bad lifter...to a man they said they would never do it. The odds of wiping out a cam lobe with a new lifter are apparently pretty high. While it was this far torn down, it was a rather easy decision to replace the cam, timing chain and gears, lifters, etc. With any luck, she should be back on the road by the end of this week. I've been having a devil of a time posting pictures recently...I'd like to try to post some more progress shots.
P.S. Just tried to post pics...no luck!!
Just to be clear..I suggested trying to save the original lifter, not 'just' replacing it.
A tired, weeping original water pump. All rebuilt and ready for install. Original distributor, all specs check out. Note date of 7D17 (April 17, 1967) for my June 2 built engine. Cast date of E227 (May 22, 1967) Never knew the timing chain cover was dated...pretty cool.
I'm going to try and upload some updated pictures. Out with the old...Federal Mogul L79 grind. In with the new...a bit more aggressive than a stock L79 cam. More low end torque with a little more "lump" in the idle. Still very streetable with plenty of vacuum.
Last edited by leif.anderson93; 05-08-2019 at 05:01 PM.
The lifter that came apart starting this whole journey. Wallowed out push rod holes. The fix...Arp screw in studs with guide plates. What the exhaust valve seats looked like...recessed almost 1/4" inch. All better. Stellite valve seats for the exhaust valves and Stainless Steel valves all around. New Viton valve seals and brass valve guides.
Last edited by leif.anderson93; 05-08-2019 at 05:14 PM.
A few random shots... While you're in there...ceramic coated the exhaust headers. A bit tough to read...3846559. Correct for this application. Look closely...Viton valve seals. Nicely dated for this engines build date of June 2 (April 24, 1967) A previous milling of the head almost wiped out the "HP" identifying this engine as being a L79 with power steering and A/C. Note the double stamp VIN...unusual but real deal.
Last edited by leif.anderson93; 05-08-2019 at 05:02 PM.
Very interesting to see your part numbers and date codes as they match closely to my car. My distributor band has the same date code 7D17. Did you find the date codes on your exhaust manifold and water pump? My exhaust manifolds are dated E24 & E25 (May 24 & 25) and water pump is D117 (April 11, 1967). My VIN is 21135.
Almost done. Tomorrow install the alternator and the A/C compressor. Fill the cooling system and fire her up and break in the new cam. If all goes well, we'll recharge the A/C system and should be driving this weekend. All good so far.
Nice effort and thx for the pix. I see you splurged for the rocker lock nuts instead of self locking nuts. Be careful those take just the right touch to lockup or they will come loose.
Nice effort and thx for the pix. I see you splurged for the rocker lock nuts instead of self locking nuts. Be careful those take just the right touch to lockup or they will come loose.
Will monitor them closely. After the 500 mile break-in of the cam, when I change the oil and filter, I will remove the valve covers and double check them. Thanks for the heads-up.
I've always set my lash with the Allen screw then tightened the nut jamming it tighter than you can pull the Allen. This requires having the lash loose until you pull the wrench. It takes a little getting used to.
05-06-2019, 11:50 AM
