I thank the lord every day I broke down and bought a 4x4!

John, which launch ramp is this?

Ray

Plastiguage is the ONLY way to do it as far as main and rod bearing clearances. My concern for you is the severely worn lifter (s) and were'd all that metal go? Or through! (That would be a concern). Gonna require a hot tank and thorough block/head cleaning to be sure, IMHO. The cam is wiped, at least on one lobe, probably.

New cam/lifters, obviously in order, and proper break in on that. I would replace the valve springs anyway while at it, as Marc said.

Personally, I would ensure the seat pressure on the springs meets spec for the cam you're gonna use .Those are all available as a kit, usually. Marcsrollin can hook you up on that! I would put in new main and rod bearings anyway and a crank polish while its down. Cheap insurance. Always polish the crank on new mains and rods.

As far at what clearances to look for on the short block? Dave at A&D, Ralph, or Barry (Obnoxious1) would be the pros, but I beleive if you go .002-.005 over spec you should be fine on a boat engine. I'd lean towards the .002 side, but just me.

Topm posted something recently about ring gap too, but doesn't sound like you need to mess with new rings/pistons.

Ray

LMAO Yeah, right, sure!

Ray

Heres some pics of the American Turbine and Berkeley 12-JG pump housings side by side.
To the left is the AT pump, the right is a JG



Opposite on this one, the left is the JG berk.



Bowl side, the AT is on the right, JG on the left



Finally, should be self explanatory by now, AT on the left, JG on the right, Intake side.



Not any appreciable difference that I can detect without a machinsts table and a dial inticator stand. Look similar enough for most of us!

Ray

That's why we're getting our licks in now........

Come show time, that thing is gonna be a force to be reckoned with! Lookin GOOD bro!

Ray

hi steve miss ya buddie

X2, why I asked.

Sorry to dredge up all that on yah though..............

Ray

My Bad!....... I assumed Nick was bringing out the new hardware! 

There's what I get for assuming!

Ray

Betting it gets a half a mil! or better! Thats one purdy machine! And the money's there!

Ray

lmao, Congrats Nick on gettin that thing done!

John, we can't all be Daytona's! I'm in the same mediocraty! (If that's even a word).

Ray

I think I asked about this, but couldn't find it. what Motels are there/nearby? trying to set up my Year, and reservations would be nice!

Ray

How about a Northstar? Lol!

Ray

I tend to agree with Glasscutter on this. In 70's and 80's stock form, the 455 Olds is a far better powerplant for a jet boat than the Chebbie or the Ford. More torque, none of them ran even AT 5k rpm, and pretty much bullet proof in that application. (Jet drives, from my understanding, were built initially around the old 215 Olds engine to begin with).

Nowadays, the advent of the "crate" motor and boat shops such as Harmin and Harden, have pushed those platforms well above what was ever expected from these engines and boats. And Jet shops, Tommy included, have built jets to take advantage of that. Not a bad thing, beleive me! It's the last bastion for us old school hot rodders, since street hot rodding is limited due to emiisions, etc, and the bar is set at these $100k+ machines you see at Barrett-Jackson.

I am a huge fan of the Olds and Poncho powered boats, and mods necessary that we used to do on street cars I, and others, have posted elsewhere, but Glasscutters on the right track! Glenn's also right, it's not an oil problem, it's over oiled for extreme rpm useage is all.

In stock form though, given the same boat, jet, etc, and given a choice between the three engines built to 70's stock spec, I would take the Olds any day. It's only because we, in our nature, can't leave chit alone where the Olds is more difficult to make competitive on the extreme side. (Mopars can easily do all of this as well, as Tom has proven recently).

Food for thought on these BOP engines. Buick built their 455 as a straight, almost complete, copy of the Olds and Pontiac 455's. When they decided to enter the Muscle Car arena, too late, in 71-73 they built 2 Buick GS upgrades. The Stage I and the Stage II. Very rare today, but both of those would probably eat the Hemi cars of the day. Ran up against a Stage I on the Docks in Erie PA back in my day, mid 80's, that thing beat me two out of two, BADLY, and I was running a 73 Nova with a tunnel rammed 427, M21 4 speed and 4 linked 9" Ford rear! That thing looked like a completely stock grocery getter, save the Stage I emblems on the fenders. I can't imagine what a Stage II is like!

What would it be like to build one of THOSE motors on a jet boat?

Ray

I ain't skeeeeeerd  It's circle boats.... I think ocean water is expected lol

Good point Tony! and kinda what I was thinking anyway when it peaked my interest. Over the summer I'm QUITE sure i've navigated the Moo over rougher stuff at Saguaro and Bartlett Lakes here in PHX at speed than I'd ever see in race conditions (Figured that chit out real quick on those lakes, thanks to you guys, Brad, Omar and GT in particular!) If in doubt, check with the Eastsiders on PB, Some of them have witnessed some my shenannigans, (The worst in a 5, at speed , probably 60-65 at the time, in full roost!, on a dare, near dusk, no boats at the dock.)

Tuna boats, wake barges, BRING'EM! I say! Driving is what it's all about. (I say that, and while I figured Moo out for the most part, this Streaker REALLY perplexes me! New cables and a PD, then we'll see where we're at, but drives totally different).

Ray

This whole thing makes me want to bite the bullet and ressurrect my old Bieser and race the damn thing! It IS, or was, more than 20 years old, but would be something short of 21' and, well, maybe a flat bottom, flex bottom, sumpin like that, lol.