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View Full Version : 73 Tahiti w/455 Olds



klattu
09-03-2000, 01:13 PM
Hello,
Looking for ideas for cam selection, will be running single 4bbl with mild porting.Engine will be out of 68 Olds Toronado...supposed to be one of the good ones(Olds)
Also impeller ideas...which one and any one use a S/S one?
I have zero interior, so am starting from scratch and can do almost any layout...thinking about 3 across front with no gap and bench down each side of engine cover...anyone built a different looking interior?
Hope to be totaly reworking boat this winter.
Thanks

dendog
09-05-2000, 01:58 PM
try calling information for Joe Mondello Racing Engines. Hes an Olds specialist from way back in the day. He built the 455 in my Eliminator back in 76 and it still runs tits, but I dont have the cam specs...sorry. good luck. By the way, if you plan on using a mechanical style diverter in the future, the seat you described could interfere with handle placement.

klattu
09-05-2000, 03:37 PM
Your right...I had not thought about handel for diverter...good point.I will re-think layout.
Do you know what impeller you have?
And of course....your top speed?

GlastronGuy
09-11-2000, 04:59 PM
Cam JM (Joe Mondello) 25-28
Run a B imp. but don't run ss, you won't have enough hp to really turn it.

klattu
09-11-2000, 06:27 PM
Thanks...will look up that cam.
'B' Impeller..OK...can you tell me why?
And on S/S Imp....are they that much heaver?
On most low performance Jet-Skis ,they come with Aluminum Imps and changing to S/S is big improvement...mostly cause blade thickness is much less on S/S, and smoother surface on blades...I don't understand why this is not more popular on Jet Boat.
Thanks for your help.

KING OF THE LAKE OR RIVER
09-12-2000, 04:39 PM
IF I WAS YOU, I WOULD RETHINK ABOUT USING AN OLDSMOBILE! OLDS MOTORS ARE NOT MADE FOR BOATS. NOT ENOUGH RPMS, AND OIL RETURN IS VERY POOR, FROM HEADS TO THE OIL PAN!! I USE TO HAVE A CHALLENGER 16FT. I HAD A 455 BORED .030 WITH BERKELEY E PUMP. DON'T GET ME WRONG, ITS WAS PRETTY FAST. I HAD AN A- IMPELLER, WITH PLACE DEVERTER. WITH AN A-IMPELLER MY MOTOR DID A TRUE 5200 RPMS. THAT WAS 75 MPH. BUT THE OLDS REALLY DID NOT LIKE THOSE HIGH RPMS. AN A-IMPELLER WILL BE YOUR BEST SHOT.
IF I WAS YOU, A PUT MY MONEY IN A CHEVY!!!!!!
I DID!

GlastronGuy
09-12-2000, 05:48 PM
Correctly set-up, an Olds is fine if that is what is in the boat now. It is expensive and time comsuming to change to Chevy. An olds MUST have oil restrictors and a marine oil pan. SS imp. are for boats over 600HP. You want a B imp because it will allow for more RPMs and that equates to more power. A little less hole shot but more top end. For LOTS of good info go here: http://321website.com/members/forum/plus.mirage?username=realjetboats

klattu
09-12-2000, 07:37 PM
A BB would be my first choice....IF I was starting from scratch....or buying new.
Olds must have been cheap back then, cause I don't know why they were put in so many boats either.
I do already have all stuff for Olds like exhaust,and other marine gear just for it,and being that it is already set up for it...best to stick with it...this will not win many races...but only paid $200 for whole thing and just want it for a few days a year.Shoot if I get close to 75 I'll be tickled!
I do agree...what advantage did an Olds have, back in the 'Big Jet Days'
5200 does sound like alot for an Olds,or at least at its redline.
Thanks

klattu
09-12-2000, 07:46 PM
GlastronGuy:
Oil Restrictors in supply line to Hydraulic Lifters?
To keep oil below heads?
Is it weight of S/S imp that needs 600HP?
Will not rev up quick enough?
Thanks Glas...

GlastronGuy
09-13-2000, 06:37 AM
Where are you at on building this motor? You really, really, need Mondello's Technical Reference Manual. The Olds will hold up fine if assembled properly and that manual has all the details. That and the other website I mentioned will get you through. The oil restrictors go under the main bearings. The Olds are notorious for pumping all the oil to the heads and leaving none to little in the pan. I have a friend who also posts on the other site who has a 455 in his race boat. He turns 132MPH in the 1/4 and leads his class in low ET, top MPH and points. (PCE/PGJ "Risky Business") On the other hand my 455, .040 over, 10/1, smaller cam than I mentioned for you, Torker, Qjet carb, heat riser passages filled, (a must if using an Al intake), 10 qt oil pan, restrictors, oil restrictive cam bearings, oil restrictive push rods, hydralic lifters, roller rockers, log thru transon manifolds, A imp in an E pump, turns 4400 @ 65 MPH. This is in a deep Vee hull. Everyone is suprised by its power in that hull. Get the manual and check out the other site too. You might be suprised by who posts there.

CV-23
12-19-2001, 01:54 PM
Something to remember is the Olds 455 weights less than the BB Chevy or Ford motor. It also has a longer stroke that produces more torque to pump water at lower rpms.....Mike.

old rigger
12-19-2001, 03:44 PM
Klattu,
I wouldn't be so quick to give up on the Olds. They are tourque monsters and great boat motors. Plenty of good parts for them, as a matter of fact, Edelbrock makes new alum. heads for them. Hot Rod did a cover story of building an Olds using the new heads, roller rockers, new intake and so on, in Oct 2000. 470hp at 4800 rpm and 565 lbs of tourque at almost 5100 rpm. Sounds like a good jet drive motor to me.
Obviously, a chevy would lend itself to countless after market high performance parts, but you already got the Olds, and if the block is good, you also got a great start.
Of course, I like different types of engines anyway. I'm the dope that's building a 500 inch Caddy for my boat.

froggystyle
12-19-2001, 03:51 PM
Klattu... Hmmmmm. any reference to "Army of Darkness"? Wasn't that one of the three words he had to say before grabbing the Necronomicon?

1quickjet
12-19-2001, 08:54 PM
Klattu, Tahitijet has a built Olds for a very reasonable price. Don't remember his e-mail, and haven't seen a post of his in a while. Try a search of Tahitijet and you should be able to find it.

cph1964nh
01-05-2002, 05:24 PM
i have an olds in my 17 ft Tahiti and have NEVER lost the lower end yet! but without the restrictors you will be cleaning the engine compartment after every use! the oil gets pushed out every opening it can find!

greg shoemaker
01-05-2002, 08:03 PM
Why did they use Olds in the boats.Did any of you ever hear of Hardin Marine. Back in the late 70's Hardin Olds decide to get in the boat business guess what ? They also sold Olds. cars thus we have an Olds in the boating industry. When I was a young man back in the early 70 's I had the opportunity to work for Joe Mondello when he was in Gardena Ca. The Olds will work fine if properly built.Everybody always goes half way and wants to run full throttle nad wella we have a bottom end failure. If you get with a good shop and are sold the right parts tha Olds will wor fine.Kieths zellmers boat Risky Business is an Olds but it's a Steve Schmits Pro Stock olds that doesn't even come close to the the early model 455 olds. Greg

Flat Screwd
01-05-2002, 08:53 PM
BB cut, B cut ,are you guys out of you minds? A Cut minimun!!! Heck this isnt Indy racing.A piss pore running Olds with 5 dead cylinders would float the valves running a B cut. Listen ,a good running Olds is a torque monster, but its all over by 5400. So use the pump to pin the motor to a reasonable RPM. Go with a AA and a good pump. Make the motor work the pump not RPM's work the motor

Aduner2
01-05-2002, 09:49 PM
I agree with FS
I would run aa impeller first. You can always trim in down if you want to spin the motor more rpm.
Unless you're up-grading the motor, I would keep it in the 4800-5000 rpm range and build as much torque up to that point.
If you can get a deal on ss impeller, I would install it. They're around $1200 and not required for your application.
A hydraulic diverter with up/down switch mounted on the steering wheel may solve you're seating idea.
Good luck

Harlem
01-05-2002, 10:45 PM
From experience, I would dump the 455! I have owned two boats with 455 Olds. They are notorious for throwing rods! Oil goes to the top of the motor fine, but is slow going back down to the bottom end, wich in return spin rod bearings. Unless you have machine work done to the block making the oil ports larger. The motors are strong though! If you were to take an easy on it and were happy with an honest 55mph, than that motor will last you fpr a long time.
harlem

Old Guy
01-06-2002, 03:38 PM
[QUOTE]Originally posted by Aduner2:
[B]I agree with FS
I would run aa impeller first. You can always trim in down if you want to spin the motor more rpm.
Unless you're up-grading the motor, I would keep it in the 4800-5000 rpm range and build as much torque up to that point.
I also agree. I'm turning a AA impeller 4800 rpm with a 455 olds. I got a lot of help and parts from Mondello. This gets almost 80 mph out of my 1972 - 18ft Sidewinder. I'm running an 8 qt oil pan (space prob w/3pt mount)and a cooler. Really should have 10 qt pan. A few years ago an old friend (80 yr old mech. engineer who built his first race boat in 1935 said "all that high rpm stuff is going to cost you a lot of money....forever". After reading and listening for a while, I think he was right.
Old Guy
[This message has been edited by Old Guy (edited January 07, 2002).]

klattu
01-09-2002, 05:26 PM
Thanks,
All this info is great!
The AA impeller idea really helps understand the reasons for chosing...and after getting in the range I need...then spring for a S/S imp.
Tahiti will be keeping the Olds...it is set up with all the special aluminum plates and exhaust.
Thanks everyone...keep up the tips...I am sure you are helping more than just me.

OneBadScorpion
01-10-2002, 08:34 PM
Originally posted by greg shoemaker:
Why did they use Olds in the boats.Did any of you ever hear of Hardin Marine. Back in the late 70's Hardin Olds decide to get in the boat business guess what ? They also sold Olds. cars thus we have an Olds in the boating industry. When I was a young man back in the early 70 's I had the opportunity to work for Joe Mondello when he was in Gardena Ca. The Olds will work fine if properly built.Everybody always goes half way and wants to run full throttle nad wella we have a bottom end failure. If you get with a good shop and are sold the right parts tha Olds will wor fine.Kieths zellmers boat Risky Business is an Olds but it's a Steve Schmits Pro Stock olds that doesn't even come close to the the early model 455 olds. Greg
Be smart, spend 27.00 and buy the oil restrictor kit for all mains and the oilpump spring. Mondello just updated his tech book and spend the extra cash for a good pan. I've eaten bottom ends for not taking greg's advise myself.

SeaSlut
01-11-2002, 06:40 PM
Klat Verratta Niktu
Froggy is still the man