I have 4.382 diameter KB Hyper pistons in my 452 I'm building. The issue started when 3 of the pistons wouldn't fit in the hole. It turns out that the skirt on one was 4.394 while the ring area was 4.382 like it was supposed to be. On two of the others, the skirt was 4.388.

Luckally, that large diameter was on the first piston that tried to go in.

This got me thinking, gee, what if this piston had been machined .002 large instead of .012 large? I wouldn't have noticed. I bet no one would have noticed. It would have installed in the block, and fine ran too. That is, until one day I ran it a little longer and harder than normal. The piston would have then sized in the bore, and shattered in a million pieces.

Is this the real reason why some people have issues with the hyper pistons while millions of others don't? 

Anyway, I called summit racing (where I bought them), and they sent a truck and replaced the pistons ASAP. Summit has my business for a long time.

Lifters are cheap, buy a whole new set.

But wait - on hotdrama.com they said you couldn't *ever* run new lifters on an old cam!
Sorry couldn't resist! :-)


Yes, I would say it is probably a broken or malled spring. The question is why did it happen - if it is from too much spring pressure, now would be the perfect time to go solid lifter, assuming you have an adjustable valvetrain (don't know what engine that is out of).  Just make sure if you replace that lifter that you break it in with plenty of assy lube, zinc additive, 2500-3000 RPM for the first 20 min, etc . No different if just one or 16 lifters, need to break it in the same.

I just bought a tunnel ram with dual holley 600's. I am going to go through the carbs and make sure everything is in sync. My question is should I stage the carb linkage, or just hook up the linkage directly to each other. 1200cfm seems a little much but I do have polished ported heads, elgin pro stock cam, headers, my "staging " question is a newbie thought, and the reasoning is, if I dont open them both wide open, I wont get the full 1200 cfm, and by starting off with one carb I wont flood it on rapid accel. I hope I am not too far off base here, although right now I'm thinkin "i might be over my head a little bit.
 I bought this setup used, but it came off a 455 olds and supposedly ran fine (yeah right)  lol, I know that if I am going to get this puppy to respong and perform like my single carb did, I am going to have to advance into re-Jetting hell, my last question (for now) is; is there a basic starting point for the jet sizing. If there are unforseen problems that I just am not aware of, or just a friendly heads-up from any of you who have been through this, any advise will be appreciated.
Thanks,
John

I've never run a ram on an olds, but plenty of them on a BB Mopar. Same concept though.

With the 600's, really you are starting out with just that, 600 CFM. The secondaries on both carbs are vaccum operated, so you will only have them open when the engine wants it. When you floor it you will have the same thing as a single 600 CFM carb on a single plane manifold, which is a good size for you. Your secondaries may not ever open fully, it all depends on what the engine wants and what secondary springs are installed.

I would suspect that dropping the jet size one or two will all that will be needed, you may not even need to do that. Run them stock and see what your plugs say. That really depends on your cam profile and head airflow.

With the the progressive linkage on the T rams, the rear carb starts opening first while the front carb is still idling, and the front 4 cylinders tend to run lean(er) at that point. You typically aren't under heavy load there so it doesn't really matter, exept you will use less fuel.
As soon as you get under load, you crack the throttle open and everything is good at that point..

welcome to the T ram club - there's no turning back :-)

Yep, get fuel filler hose. The std rubber line will start to fall apart after a few years, then all that crap is in the tank and then in your fuel system....

Is there a place that sells a bundle with those in it (think AUI cable)?

I would tap it and put the plug in. The penalty for failure on this one isn't that great. The exhaust will just push it out (but still try and keep the shavings to a minimum). If you match the tap and plug up right, you probably won't even have any shavings in the soft aluminum (of course you could use vasoline to trap the gunk and clean it afterwards).
That is what I would do- your mileage may vary.

so in short, if you cant tune an engine without a weather station, get forged pistons

Yep, forged are the way to go. This build is exceptionally low buck we'll see how it all turns out. If it doesn't work and I shatter a piston, I'm out the $267 I paid for the set....

There is nothing inherently wrong or better with a hyper, cast or forged pistons in a good running / tuned engine.

The issue becomes when you add nitrous (heat) or too much timing (pinging).

Hypers can't handle prolonged detonation - they shatter.
Cast can't handle excessive heat like you would find on a 400 shot.
Forged can handle both without damage (to a point), at least a lot more than either of the other ones can.

Saying that - I'm running hypers on my new build.

It was quite a pain in the ass those rods, when I got them back from balancing the card showed that they were heavier than a stock set of cjs. So back to be balanced again. The when I got them back they ground on the nuts to balance the big end. Back to the balance shop again. I will tell yah it was a mofo.

You aren't too far from me, who did you use to balance the rods? I don' tknow that I would trust anyone who took liberties with my rod bolts...

Nothing wrong with probes, I know a lot of guys with SB fords running them.

Personally I've had good success with KB forged. The valve reliefs are really deep and they can handle quite a bit of NOS. The hyper KB's hold up well except under detonation, they even have a carbon gap between the top and 2nd ring which really aids in the lifespan.

Holleys aren't as bad at this, but Mallory pumps cannot pull uphill at all. The grabbing the fuel from the pump inlet side is an electric pumps hardest thing it has to do, anything you can improve here will help the pump. You have the trade off of low enough so the fuel isn't being sucked uphill at 1/8 tank, but high enough so it isn't sitting underwater when you have a bit of water in the boat. You want the shortest fuel line you can get, optimally 2 pumps, 1 at each tank. Failing that, one pump on the transom will split the difference between the tanks and will be the best compromise (and will still work)..

Mechanicals have the opposite problem- they can suck the tank from a long way away but have issues pushing that fuel out.   

  A real stereo?  Sounds to me like you're setting up for a full blown concert.  Do you include 24" wolfers too?    I've got a regular stereo with a CD player.

I've got the 10 gauge wire for power and ground.  Also have a 30 amp breaker that I bought from a electronics store for a lot less than what the marine shops want for the same thing.  I may run a breaker box or fuse box under the dash as well, although I don't know that it's really needed.

Naa, just 15's :-)  10G wire is good for 65A, as opposed to 12 gauge which really is only supposed to handle 40A.

I would always be on the safe side and use the breakers - electricity can cause fires - usually a bad thing in a boat. If something shorts under the dash, there is always the possibility that the heat generated will melt the insulation wherever the worst spot is ( you know, like where the gas is!).