Okay, I keep hearing all the horror stories so I am looking for advice before I wind up a statistic. I will be running a Comp Cams 274S flat tappet in my 427 BBC. I have added the Isky pin oiling lifters (hopefully a little insurance)to feed more oil to the lobes. I have already set lash at .016 which is on the cam card (Seems tight, and should I loosen this up a little for initial startup??). I will be priming the motor right before I drop the distributor in ;) . Any advice on initial timing would also be appreciated!!

427 (439 .060)
Iron Oval Port Heads 781s
Comp Cams Solid 274 Flat Tappet
10.3 static comp SRP pistons
MSD HEI
MSD 6a Box

I don't know how agressive that grind is, or if you used dual springs, but I would break the cam in on the outers only. Tight lash is fine for run-in. just before you fire, run the engine up to TDC, or specifically, 8-10 BTDC, with the #1 wire hooked to a spark plug resting on the engine, energize the ignition and turn the distrib slowly until the #1 plug fires. Lock down the distrib and you should be very close to 10 BTDC timing. Ready to prime the carb and fire.

The cam is right around .570 lift int/ex. It does have dual springs. Thanks for the advice :D . Anyone else using the isky lifters with pin oiling on the lobe face?

If you are worried, you should know exactly what all of the springs measured which is a common thing to know. If you don't know and they are double springs, I might be worried too...

AT LEAST know what the installed height is and what the catalog specs them at, although I don't trust catalog data and measure each one.

Add GM's EOS to the crankcase before priming.

Touché Doug, 1.8 installed height @ 120lb seat. 325lb @ .560 . Coil bind @ .680 valve lift. .700 between seal top and retainer. Anything else needed... I really don't want to pull the inner springs unless the consensus is that I am in for trouble otherwise (from people in the know). Normally I wouldn't be worried but it seems so many people are having problems during break-in.

I have witnessed an L88 motor fired under full spring pressure long enough to set timing and idle speed (about 3-5 min. run time). After that the motor was taken to 7400 rpm for a few seconds (I about ***** my pants as this was in a closed dealership garage w/ open headers). Then the car was taken out of the garage bay and full throttle burnouts until the owner came out screaming to shut it off. Motor ran great and never had a problem! I guess sometimes rules are made to be broken graemlins/clonk.gif

I built an L88 to specs once. Brother, they're loose as sin. 3-3.5 thou on bearings, 5.5-6.5 on the skirts etc etc. That's race motor stuff, real motors don't like that kind of abuse! smile.gif Plus. the 88 cam is really gentle ( but HUGE) as compared to your XS grind. No comparison.

Hey, I don't know crap other than running the cam in on outers is a real nice way to do it. Maximizing the chances of success. I just followed the instructions on my cam card, what do I know. For the few mintues it takes to pop the valve springs off and replace a spring...hey, you're probably a helluva lot luckier than me. I have to make my own luck by being exactly correct.I'll always run in an agressively ramped cam like that. Part of my being so lucky on running them in!

By "oiling pin" I ASSUME you mean there is a oiling hole on the lifter face? I use those as well, more for the long idles that a street cam is exposed to , rather than run-in.

If you ever had to tear down a new motor fully, to the point of taking the block to a wanda=wash armed with long gun barrel brushes for the oil galleys, you'd realize why I think R&R'ing the springs is a way cheap price to pay. That SUCKED. Do what you must, like I said, I aint lucky enough to pull shortcuts. Your stars may be aligned much better!

Okay, I guess I will be pulling the inner springs to make you guys happy ;) . What is the easiest way to do this without dropping a valve? I don't have an air compressor to pressurize the cylinder. Can I build enough pressure to hold the valves by bringing each cylinder to TDC on compression stroke? Any help is appreciated smile.gif .

You need to get a compressor. Maybe rent one? That's about your only choice short of pulling the heads.

Just bring the piston all the way up, & push some rubber tubing in the spark plug hole.... It works like a charm, especially if you're using domed pistons..


Scott

To hold the valves (I just did this on my new cam run-in smile.gif ) I used a old spark plug wire. Remove all plugs, get cylinder you are going to work on close to the top of the cylinder (I made sure that both valves were closed when piston was up), back off alittle, feed old rubber plug wire into sparkplug hole (use a long one so it will coil up inside), turn crank to get piston up to TDC with the old wire wedging up between the piston and valves. Remove the valve locks and inner spring, reassemble the valve. Make sure to leave some wire hanging out the hole so you can lower the piston and pull the wire back out. This worked like a champ and the valves did not fall in.

Thanks guys, After reading poor Cody's post about his cam going flat and talking with others here I am definitely going to pull the springs for cheap insurance. graemlins/beers.gif

Oh and member 427L88, I never said you were an anal retentive freak so please get your facts straight.
;)