MILD THUNDER

iTrader: (3)

My next setup will be solid rollers.

distantthunder

Good job Tom, it's been a crazy year with these builds so far! I'm curious to see what you find when you open it up.

TomZ

iTrader: (2)

I haven't gotten the lifter out yet... only viewed via a bore scope, but the lifter was adjusted this way, and from what I can see, the plunger is about a 1/4-inch down in the body. The backfire didn't cause this. It's the reverse.

I readjusted all the valves back in November after the initial dyno session/run in the boat (I had an intake that was clacking on number 5). I adjusted number one per the instructions that came with the lifters, and thought nothing of it. I'll be looking at all of them when I get it torn down.

I have four lifters coming, and I'm hoping I do not find any other issues. They're all coming out for inspection. I should have ordered another set of lifters all together (something other than Comp... well... except for their new short travel lifters... I hear they're actually pretty good), but then that would have required new pushrods because of seat height differences. My geometry is good (per wear patterns), and if I can get these to work, then I'll be happy.

TomZ

iTrader: (2)

Joe, I actually have a set of Crower solid rollers coming for this as a backup. They're the lifters that were originally used with the engine that my heads were on (468 Chevy). I have the pushrods and everything. Would only be a matter or determining the proper lash with the hydraulic profile. The duration would drop a little, but RPM would be extended. I'm not sure that I would want to go down that road, but it's an interesting approach.

One thing though, my Comp 953 springs are definitely on the edge of working with these lifters. Comp recommended them for the cam using my 854 lifters, but mentioned that they were really meant for a solid roller.

In my not so educated opinion, I do not think the springs are beating the lifters to death... I think I have a couple of bad apples maybe.

TomZ

iTrader: (2)

Got everything apart during lunch. I'm getting good at taking this thing apart quickly... great! Anyway... All the lifters look good with the exception of the number one intake's lifter. The cup is down in the lifter a quarter inch and if I invert it, the cup will come almost to the retainer. Safe to say that something let go in that one.

I'll starter prepping for new gaskets tonight sometime. Hope to have her all back together Friday evening.

vintage chromoly

iTrader: (3)

I'd put the solid lifters in the engine.

A friend just went through this BS with a set of comp came hydraulic lifters and switched out to solids.

TomZ

iTrader: (2)

Anyone know the lash settings for this cam? Merc 525 EFI or Crane 741? Iron block, aluminum heads?

Thanks!

TomZ

iTrader: (2)

Well, it's fubar.

New starter, two new pairs of roller lifters, went through the valve train, but didn't do compression test because I thought I found the smoking gun. Started her up, backfired for a second then ran rather rough. 5 inches of vac at idle. Seems okay when you rev but very lazy to do it. Thinking I have a burned intake valve, bad head gasket, or who the heck knows!

I should have checked compression.

An hour of dyno time plus maybe three hours of easy run time in the boat... is that enough time to waste a valve or a seat? I'm really upset about this.

mike tkach

iTrader: (3)

tom,if the tuneup is wrong,espically on a supercharged engine the exhaust valves& seats can develope a bad seal in a hurry.i am not saying that is your issue but it sure is a possibility.

TomZ

iTrader: (2)

Backfires are all out of the intake. Nothing out of the exhaust side, and this thing is fat.

I'll dig into some after I'm done being pissed off at it. I'm not ruling out a spark plug wire issue.