[IRRebel]

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

[GT Jets]

I'm considering a mini droop.

Based on what?   

BTW, If Olds had larger runners in the heads, I would say a tunnel would be the correct answer, but the Olds heads are pretty under designed as far as a high RPM motor is concerned..Just my opinion.

GT

[double-d]

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?

[GT Jets]

I read that article before..Pretty cool stuff...However, you may disagree here, but trust me on this...This could turn into a month long debate

The application of the engine in the article is very different from your jet boat...

Your jet pump will absorb literally everything you throw at it HP wise...That being said, your vacuum levels will be atrociously low because of the engine load...Imagine running your 442 wide open throttle in high gear going straight up the Grapevine and not letting off. That is what you are asking of your boat motor... No car buff in there right mind would ever do that, even on a bet...

With all that being said, if the engine load is high, causing low vacuum levels, what would be the best remedy for that?  You got it! more air and fuel, so bigger is better (in this case anyways)...

With all do respect to all the automotive enthusiasts, they don't know chit when it comes to a badass jet boat motor tune...

It is very difficult to over carb a big block in a jet, as long as you have good velocity across the venturies, it will work killer, vacuum has little to do with it, but is a great tuning tool...

I'm telling you right now, keep your eyes open for a good used Victor and you will never look back. 

The thing I hate about the Torker is the looks, but a great manifold performance wise, the Victor is a better looking piece IMO. 

I would love to see some back to back tests on each, but we all know that's not going to happen...

Another note, a tunnel ram does different things with the air, so 1260 CFM sounds like a lot, it really will not flow those kinds of numbers, but the tunnel ram uses the advantage of working less hard to obtain the air fuel charge accelerating it toward the intake runners....

GT

[GT Jets]

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

[propless]

double-d, Ive been looking for this for you for a bit and finally found it.  Heres some more reading for you,  http://www.performancemotorsportsnews.com/newsdisplay.php?newsID=177 .  Its an article called "the Practical Olds" written by Tim from TUFENUF MARINE PERFORMANCE (AKA  TIMINATOR on here), not sure why, but he hasnt been on here in a long time, maybe he dont love us anymore.    There is great info about the Olds motors in there, there inherent issues, how to deal with them, and parts recommendations (look at the section about intakes).

[SS-201]

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.

[jet boat performance]

The majority of Olds "mods" are common sense engine 101 , the rest are IMO can be attributed to Joe Mondello  Joe really did pioneer the majority of what makes this motor work , like him or not (not the current "Mondello" administration) Getting the 455 motor to make good power lies mostly in the cylinder heads and valve train , making it live is all about the oiling system , heres Josh making a few of the mods to the 468 (455) aluminum head deal, were building right now , including but not limited to external oil returns (note the returns at the block skirt area) Tom

[jet boat performance]

BTW Cant say that Timm doesn't have a good recipe but the majority of Olds "mods" are common sense engine 101 , the rest are IMO can be attributed to Joe Mondello  Joe really did pioneer the majority of what makes this motor work , like him or not (not the current "Mondello" administration) Getting the 455 motor to make good power lies mostly in the cylinder heads and valve train , making it live is all about the oiling system , heres Josh making a few of the mods to the 468 (455) aluminum head deal, were building right now , including but not limited to external oil returns (note the returns at the block skirt area) Tom

[double-d]

Yeah I would love to squeeze and I had a kit on it a few years ago.  I could really find a feesible place for the bottle that wasn't real close to headers, plus I would have killed space for chairs, anchor and what not.I took it off. still got the kit, maybe someday i'll do it up.

Well rigged up the boat with the vac gauge keeping the 750, and t/r on there for now.  I got some good base line runs of 13hg at idle and 2hg at wide open doing 59 on gps. 
 
After reading the a practical olds article i saw in there that the timing should be maxed out at 2500-2800. I went back to the msd chart and noticed the ignition curve is stock at doesn't max out until 5k with 21 degrees total advance. My baseline timing is 12, so i bumped it up 14 ran it, gained 1hg at idle but wot was hardly noticable.  Bumped it up to 16 degrees  and with 15 on the vac the engine sounded healther and starterd better. Got 60 out of it. Then went up 2 jet sizes on the secondaries. that as hardly noticeable. But i didn't do a full throttle kill and check the plugs. I ordered an advance kit to change to a more agressive curve. Any suggestions on timing curves to use. I'll swap to the 850 after that's dialed in.

here is some info i had found on carburation, this i very simalar to what my holley carb book says. I also read 3hg for a 2 barrel and .75hg for dual 4's.

Whether a carburetor never meets its rated airflow capacity or exceeds it is to some degree irrelevant. The key point is that for maximum performance a carburetor must deliver the airflow capacity demanded by the engine. As a general point of reference, if manifold vacuum exceeds 1.5 in/Hg (at WOT) on an engine equipped with a four-barrel, the carburetor is too small; if it falls below 1.5 in/Hg, the carburetor is too large. Obviously, there is at least one hole in that theory because any manifold vacuum level above zero represents a throttled condition, which means an engine won’t produce maximum power. However, if a carburetor is large enough to drop WOT manifold vacuum levels to zero, drivability issues at part throttle may result and low airflow velocities may negatively impact power. The key is to find that magical airflow capacity that keeps air velocities high, without excessively restricting flow.

I contacted comp cams to see if they have any dyno charts of what the hp/ torque numbers look like with the cam -4 straight up and +4 advanced. The guy said they don't have anything.  I replied with I find that hard to believe they haven't done that with one single cam in there whole inventory.  Please forward to the dyno dept. We'll see what he has to say.

I am leaning to the torker manifold, 850 then maybe the double A. I know the victor is probably better but I think I want to build for torque if double A goes in. But that won't be until next season since my test water, lake hodges closes halloween.

[GT Jets]

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

[double-d]

....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

[GT Jets]

....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

[double-d]

now that's funny!

[GlassCutter]

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)  

[double-d]

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 Jets]

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

[quick olds]

Kinda late butbstay with the a and run it in my opinion tho if Ur gonna run an olds make sure u do the oil return mods to heads block ect so u can run high rpm my motor don't have piling issues anymore 10 at pan drilled the returns and restricted push rods help a lot keep the oil in the pan and run 5500 for a good mile or so i have kinda leafy staying in it longer but I think it'll be fine

[simidan]

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.

[quick olds]

Nada prob hit me up if u need help I'll show I what i did to my returns on my heads and block and mondello has the push rods kinda spendy but well worth it and if Ur in my area I'm always ready to help a fellow olds guy or girl 

[double-d]

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.