I'm not going to get all technical into why I agree Proppy and GT are right on all this. PM me if you want that whole storm. lol.

Leave it at this, T/R's in general are very high rpm only devices that require a TON of compression, Cam, fuel (Both pressure and volume), and forethought into their setup. Not many of these things are very conducive to the Oldsmobile engine, I'm sorry to say.

Vacuum secondary vs mechanical, I run vac, and run inline because I beleive there's inherent bank to bank rich/lean conditions running larger carbs sideways unless you run 1:1 as Proppy does (Firing order comes into play........its a LONG thought process and reasoning behind this).

There's an inherent hate for vac secy's here that really is unfounded, even on T/R's. Trick is spring selection, and that's probably the ONLY info you will gather with a Vacuum Guage that might help with that. Other than that, a Vac guage I don't see doing much for you that a can of WD40 can't in checking for leaks. I did it through trial and error, and the weird setup I have. I duplicated this so my "ship" will have twin setups the same way on 2 engines and jets! Thanks to Proppy and Jim Brock I was able to replicate that arrangement. 

The only real insight as to how a T/R is working and to tune it is throttle response, reading your plugs, and performance. You will do this MANY times setting one up right. 2 of those are seat of the pants measurements, only 1 a technical measurement, if you notice. Yes, on a jet boat, pump setup will have a LOT to do with it, just as in a drag car, gearing and tranny issues are involved as well.

Single 4 BBL Tunnel Rams, regardless of what engine and carb on them, IMHO and don't take this the wrong way, are like watching someone else get laid. You get an insight as to what it's all about, you get to be in the room for the show, but you don't get to experience the actual thrill of it for yourself!

Stick with what works on the Olds. A good hi-rise single plane, large carb, cam and compression to work with it, then the pump must match that. I also have a Jacuzzi/Olds combo that will be going through some "changes" over the winter (Among other projects going on). It will stay Jacuzzi/Olds, but as far as where it will end up? A very decent and reliable Hot Rod, but probably nowhere near as fast as others I have laying around.

My .02

Ray

based getting the pump in the water more and a bit more roost.  It seems like the droop snoot is the hot set up, but i don't wanna screw around with cable and linkage BS. I figured a mini droop would be a good comparmise.  if it ain't gonna do jack, well thats why I'm here, to figure out what works.

Well, im getting the message that tunnels suck, you ain't hurting my feelings but thats what i'm runnin' at the moment.

It's cheaper to change the manifold then to F around with dual carbs, linkage, finding a dual quad top, blah blah blah.

Ray, the idea i'm planning is using the vac gauge is see how the changes effect the motor. You had mentioned throttle response, plugs and performance. The vac gauge should tell this, since we all know an engine is a big air pump. If I make a change that for example increases manifold vac at wide open throttle then I know it was a change for the better.  Vac also helps for sizing power valves.

I asked before if the guys who had tunnel rams and dual carb about there secondaries being vac or mech because IMO 1260 cfm is way over carbed for the volume of air/fuel one cylinder can process. But maybe i don't know shit.  If they were vac then the secondarys only open when there is enough vac to do so.  Since his boat idled better and better throttle reponse, I was thinking the secondaries where not opening or only at the top end... When the 1 to 1 linkage came into play that but the kabaash on vac seconday theory.  Gt mentioned an 850 and a victor doing about the same rpm. Shit i'd rather change a manifold stuff a double A in the pump and rip.

 I foundnthis article
http://www.jpmagazine.com/projectbuild/154_0711_455_bigblock_project_murderous_overkill_part_vi/index.html

Although we pushed Welfringer for specifics, we were unable to learn much more than the Edelbrock Torker manifold (PN 2730) underwent Mondello's proprietary blueprinting process. In a nutshell, the intake was port-matched to the cylinder heads using Mondello's gaskets and the plenum and ports were reworked to increase flow-a lot. Mondello also port-matched the Edelbrock Victor manifold (PN 2810) that we tested on Westech's dyno. The Victor was too macho for our engine, proving it needed even more compression, camshaft, and rpm to be happy. The Mondello-modded Torker proved to be an absolutely perfect match for the rest of the combo.


Displacement: 468ci
Bore x stroke: 4.185 x 4.250 inches
Compression ratio: 10.75:1
Rod length, center to center: 6.735 inches
Piston deck height: 0.002-inch
Chamber volume: 77cc
Rod bearing clearance: 0.025-inch
Crank endplay: 0.004-inch
Piston-ring end gap: 0.014-inch (top), 0.018-inch (middle), 0.025-inch (bottom)
Piston-to-wall clearance: 0.005-inch
Camshaft type: Comp Cams solid roller
Valve lift: 0.640-inch (int.), 0.649-inch (exh.)
Duration at 0.050: 268/276 degrees
Lash (hot): 0.020-inch
Lobe separation: 110 degrees
Valve spring (seat): 250 pounds at 1.750-inch

They have a monster cam in this thing and i they say victor is too much and the torker is the way to go.  Anyone run a torker and see better results?

based getting the pump in the water more and a bit more roost.  It seems like the droop snoot is the hot set up, but i don't wanna screw around with cable and linkage BS. I figured a mini droop would be a good comparmise.  if it ain't gonna do jack, well thats why I'm here, to figure out what works.

Not saying it wont work, quite the contrary, just wanted to know what the hull was doing to warrant the droop. What you are doing by adding the droop is change the height of the thrust line (also called the "X" dimension) and quite often adversely effects performance, especially on bow light hulls...

Droops and wedge is a "tune" thing, I seriously doubt any two boats react the same with the same parts....Use what works on yours, not what worked on someone elses, although someone elses is a great starting point if their set up is similar in many ways to yours...

I hope I am not confusing the issue more...I am trying to give real world examples, but I have been programming buildings and working on electronic crap all day, so I could seriously be blowing it out of my ass..

GT

Picking up 1000 1100 Rpm takes more than a carb or manifold change. Put a nitrous system on with will power to not use it all the time a adjustable plate so you can change HP. You won't need much of a shot to get the rpm you want. Probably he cheapest way and you don't have to use it constantly like a big built engine. Takes will power not to abuse the nitrous, but will haul the mail,like was suggested I wouldn't turn 6 K all the time.

IMHO you can safely drop below the 1.5" WOT vacuum in a boat without many issues....The reason is again engine load....When it gets to 3/4"to 1" is when things are really happy, think in velocity, not vacuum...

You started the thread by saying you wanted more RPM, and now your saying you want to go to an AA...  

It is my humble opinion again that you stay with the A and use the Torker and the 850. With that combo, you really can't miss as far as the set up...

As for the timing issue, all in by 2,000 or even locked out with a separate ignition switch to get things spinning works with a radical cam...It improves the idle quality and dramatically improves throttle response...

If there are boo-boo's in this post, it is this damn keyboard    I think someone was using it as a wheel chock or something..

GT

....all in at 2k, wow that's quick, I'm not going to run that curve first, my compression is too high to try that right off the bat.

Well your starting to talk me out of going for the higher rpm when you said its eaiser to go for speed.  Since the olds motor doesn't quite do so hot up in the higher rpm range and its got gobs of torque i figure the double A will be a safer way to go. RPM wise. Swapping the impeller will be the last thing I do.  I'll try the can't miss setup first.

I should be there at 3/4 to 1" with the 850

You will be glad you did...

FWIW, my 468 Chevy has 11.5:1 compression and is all in at 1500 RPM with an MSD..I run 50/50 102 AKI and pump gas...Pulls an A to 5250 RPM consistently...No problem...

I can explain why...

A jet pump uses very little horsepower up to about 3,000 RPM, there is a very small load on the engine, not like a four speed car that has to muscle it's way up to speed, think of it like a ridiculous stall converter, it let's things spin before the real work begins...  

I will try very hard to not steer you wrong..    I am not a trained professional, but play one on the forums...

GT

I will try very hard to not steer you wrong..  Wink  I am not a trained professional, but play one on the forums... Grin

We got lots of other guys for wrong info.   Just say the word and we will put you in touch with Vegas crowd.    Or Omar  (sorry Omar I had to)  

Success! took out the boat this weekend with the light silver spings in the distributor. +16 base timing and 21 advance bushing. So a total advance of 37. Gained gained 200 rpm and maxed at 5100 rpm. Didn't get any MPH readings though, too many fisherman out there and the speed limit is 35.

Swapped over to a piece of shit Ebay 850 Holley knock off mainbody and base plate. Don't buy 'em!! The float bowl screws weren't tapped right, down leg boosters are crooked and the accelerator pump nozzles squirt so wide the fuel doesn't go directly in the carb.  Total Junk!! Either way I Gained 100 rpm, peaked at 5200! Vac looks like it dropped down to 1-1.5.

Think I'm going to get the timing up another degree or 2 and lighter on the advance springs. Stickin' with the 750 holley for now, savin' up for a better 850 and the torker intake.

 

GT

That was good reading and will help when I get around to building a motor this winter. Thanks for bringing this up again Quick Olds.

Yeah got oil mods galore, -8 returns on the back of the heads going back to a 10 qt oil pan, oil restricted cam and main bearings.

what carb size carb your runnin'?

This year I only reduced the timing curve time, she runs a a lot better. I bought an 850 holley and a torker intake but haven't put it on yet.