olds 455 advice

[dekmaster]

Hi All,
i've been reading this forum for a couple of weeks and I have searched and read all of the articles on the olds 455 and jets in general. I am new to boating and I recently bought a 1973 Rogers jet boat with an olds 455 and berkely pump. This boat is old it has stock everything. I don't need super performance out of it but i do want it to run like new.
This is how it behaves:
It planes out at 3800 RPM and I haven't pushed it above 4600 RPMs and at these revolutions it goes 50 miles an hour (GPS). I know these boats should do at least 60~65 MPH. I looked at the carburator at WOT and noticed that the secondary butterfly valve never opens so its starving two jets from air. The engine runs great no misfiring smooth like there is nothing wrong. But there is this lack of power! I think I want to change the carburator and intake manifold. Carburator for the reason mention above and intake manifold because it rusty since it was sitting for 5 years.
Can you guys please let me know how to get designed power from this engine and maybe carburator and manifold recommendations. Also maybe some pointers about the impeller. i don't understand what loose means (in terms of impellers anyways).
Thank You Very Much!

[HotDogz]

For a carb, I run a Holley Marine 750 w/mechanical secondaries. With a jetboat, you'll want mechanicals as opposed to vacuum. As long as your cam is stock or mild, a 750 should suffice. As for an intake, again, with a mild cam, you could getaway with an Edelbrock Performer. I think they are good from 1500-5500 rpm. If you bump up the cam at all, I would go with a Torker Manifold (single plane)

[Wally_Gator]

Dekmaster,
Loose pump?
Probably so with the RPm's you mention. The impeller fits into a wear rin in the body of the pump. If the wear is excessive due to misuse of the pump or just alot of use, the suction of the impeller and thrust are lost through gaps between the impeller and the wear ring.
If you look up through the intake grate of the pump you may notice the edges of the impeller are slightly rounded. These and more things to do with the bowl can cause the boat to plane out at higher rpms. It may be a good bet to have a pump shop look at your pump.
Hotdogz has good advice regarding the motor. Just make sure you pay attention to the oiling system. These motors are notorious for pumping oil into the valve covers and starving the pan.
Walter

[Old Guy]

The Q-Jet carb has a little link on one side that is tied in to the automatic choke. It won't allow the secondaries to open before the choke is full open.
Just a thought

[Back Forty]

If you can turn 4600 rpms @ 50 mph, your carb and engine are fine. Your problem is the pump. Q Jets don't have vac secondaries and will do more than fine for your needs it sounds like. The holley isn't needed. Put your money into pump work and you'll be as happy as ever. Either turn the pump over to a shop or re-do it yourself, miles ahead.:)
Another good place to dig up any Olds info is
www.realoldspower.com
good luck.

[seho]

Don't forget that losing the stock, cast iron intake and going with aluminum will drop about 50 lbs. off of the boat! Ok maybe not quite that much but those things are heavy. I have good results with my quadrajet but when I find a decent deal on a Holley I'm going to try it. :)

[396_WAYS_TO_SPIT]

Welcome to the boards;) I had a stock 455 olds at one point in time and she was acting like that with a quadrajet carb. i bolted a holley 750cfm vac secondaries right out of the box from autozone for only $200 and she woke right up. Another good thing is to loose the stock"boat anchor" intake and add a place diverter and you will notice a difference. I am with the other guys about checking the jet. BUT, if it runs well then leave it for the summer! TRUST ME, once you start disassembling your boat sometimes it takes alot longer than you think to puit it back together;) Run it for the season then do your mods in the winter!
Just my lil' ole' 2 pennies though;)
396

[Back Forty]

seho, it'll probably cut more than 50 lbs!!!
My boat had a marine holley on it when I got it. I tossed it in the round file. I replaced it with a Q jet from a '78 Caddy 425. This is an awesome carb. The 800cfm variety with factory 74 jets and enlarged air bleeds. The non Olds part which who cares is the side entrance fuel inlet. I spliced an aeroquip fitting on to the Q-jet inlet fitting so I could run aeroquip lines from the mechanical pump to the carb. We built a spacer to be able to use an aftermarket tall style flame arrestor and incorporated a tube through the side to be able to pipe in the vent from the fuel pump housing. Keepin' it legal I guess...:rolleyes: :wink:
And to agree with what old guy said, make sure the lock out from the choke isn't your problem which it probably is. You can test it by backing off the choke all of the way which should keep the lock out from occurring. Very easy to do. The lock out linkage or arm is obvious and very visible. Take a look. and get a pic if you can.

[dekmaster]

I actually had the boat checked out before i put ti in the water and the mechanic said the impeller had a couple of nicks and scratches, but that's from normal wear. How can I adjust the choke to open up the secondaries and if this indeed is the problem how would it affect the engine if the secondaries don't open up?
Thanks Again!
Dennis

[dekmaster]

What is the stock horsepower of the olds 455. What kind of impeller should i use. Also what should I be looking for in a jet pump tuneup.
Thanks

[GlastronGuy]

Personally, I run the QJet and it is just fine. BUT, I had it done by a pro. My pump is tight and I run 4200 - 4400 RPM at 61.7 gps in a deep V. 32 total timing and Pack A Jet logs.
You can buy pump rebuild kits from places like CP Performance. If you are mechanically inclined, you can do it yourself. Be sure to pay close attention to the tolerances between the impeller and wear ring.
If you are not mechanically inclined, have a pro do it.

[Back Forty]

On the lock out, there are two basic setups as far as I have seen. One locks out the air valve blades which is the upper set that you see in the secondary bores. This lock is located just behind the choke blade area or just aft of the primarys. The older style locks the secondarys out by keeping the actual secondary blades shut down in the throttle plate. The linkage is a stop that locks a dow pin located wher the secondary shaft exits the throttle plate on the side.
To adjust the choke off observe the round housing hanging off the side of the carb. You should notice three screws around the outer circumfrence of the housing. Loosen the screws and use a large flat blade screwdriver in the obvious slot designed into the cover to make adjustments. Before you adjust it, take notice of the index marks on the lid and housing. Mark where they line up so you can go back to it. Turn the lid counter clock wise until you notice the choke blade is fully relaxed. Regardless of what lock out design your carb is using you should see that the lock is not set anymore. From the factory, the carb uses vaccum from the air cleaner housing or flame arrestor to pull air from the choke stove through the choke housing which should release the choke once it's warm. If yours is not hooked up or you are using a non restrictive flame arrestor then your choke may never release. I am running an electric choke on mine. My advise is to remove the lock out mechanism. Sometimes these thing will lock out regardless of the choke.
As far as factory HP, the different companies advertised different numbers but I see people talking about up to 390 hp setups (W30 Cam..?). Mine was a 330 HP package as is stated on the title.
I'll get some pics of my carb setup tonight.
If you doing 50mph at 4600 and your pump is let's say "healthy," you may have a B impellor or something..?

[dekmaster]

Should I get an A impeller?

[Back Forty]

With all else being correct, I would say based on what I have read and seen around here yes an "A" or trimmed up AA would be the proper setup for a more or less stocker 455 Olds.
Mine is running a trimmed up AA done by a pump builder here in Oh.
Did you check out the choke thing?
I took a few pics of mine for reference. My setup has the choke lock out that locks the secondarys out from the throttle plate.
Mine is an old stocker more or less. I'm trying to keep it simply maintained for a while which sounds like what your looking for.

[Back Forty]

Flame arrestor spacer

[Back Forty]

Secondary shaft end with the pin that is used for the choke lock out. If you look closely you can see the arm that locks the pin.

[GlastronGuy]

Damn image center
:(

[GlastronGuy]

I removed the choke from our QJet. I never boat when it's cold anyway.

[lilrick]

455's.....make a great anchor.

[GlastronGuy]

Originally posted by lilrick
455's.....make a great anchor.
Maybe we can tie one around your neck?

[lilrick]

Originally posted by GlastronGuy
Maybe we can tie one around your neck? hehehe

[lilrick]

I had SMOKED 455 OLDS for lunch 3 times last week and it was sooo good ...

[dekmaster]

Re: lil(d)ick
I paid 2k for my boat how much money do you have in yours? If I wanted to blow lots of money I would get a new engine every time instead of an oil change.
DEK

[396_WAYS_TO_SPIT]

Originally posted by lilrick
I had SMOKED 455 OLDS for lunch 3 times last week and it was sooo good ...
I'll run titles for the huges tail against yours:D with my little olds and my "non flowing" jaccuzi pump. :D :D
Oh yeah and by the way I paid $1000 for my boat:D :D :D
ASSCLOWN:yuk:
396

[lilrick]

Originally posted by 396_WAYS_TO_SPIT
I'll run titles for the huges tail against yours:D with my little olds and my "non flowing" jaccuzi pump. :D :D
Oh yeah and by the way I paid $1000 for my boat:D :D :D
ASSCLOWN:yuk:
396 you got ripped off, you could try asking a knowledgable boater friend to go with you the next time you decide to throw away a grand ! I spent that much on my SS impellor

[lilrick]

Originally posted by 396_WAYS_TO_SPIT
I'll run titles for the huges tail against yours:D with my little olds and my "non flowing" jaccuzi pump. :D :D
Oh yeah and by the way I paid $1000 for my boat:D :D :D
ASSCLOWN:yuk:
396 what is "huges tail"?

[396_WAYS_TO_SPIT]

Originally posted by lilrick
what is "huges tail"?
ROOSTERTAIL You damn YoYo:eek: :eek:
You need to learn a little respect before you come on here bashing someone about thier motors or boats! If your going to post here, respect here,If not get out of here! I am sick and tired of assclown people like you talking smack about someone thats trying to ask for help. This is a place for learning and sharing great experiences about the best lifestyle in the the world-----"Boating"!
COMPRENDE-Dumbass
396

[GlastronGuy]

lilrick (http://community.webshots.com/photo/1468692/1470708JfMsATTpzI)
http://www.***boat.com/image_center/data/520/3951470708JfMsATTpzI_ph-med.jpg

[396_WAYS_TO_SPIT]

Originally posted by lilrick
you got ripped off, you could try asking a knowledgable boater friend to go with you the next time you decide to throw away a grand ! I spent that much on my SS impellor
Oh and one more thing! I have 2 boats for your info! When your ready to get it on just let me know. Better yet I'll even dust your ass in my friends boat with the BBF I just built.

[lilrick]

I can't believe how upset you are. Are you a little sensitive today ?I'm sorry if I hurt your feelings

[GlastronGuy]

People are just tired of the bashing.
If the Mod had any guts he'd ban you but we don't have to worry about that.
:D

[v-drive]

Originally posted by 396_WAYS_TO_SPIT
ROOSTERTAIL You damn YoYo:eek: :eek:
You need to learn a little respect before you come on here bashing someone about thier motors or boats! If your going to post here, respect here,If not get out of here! I am sick and tired of assclown people like you talking smack about someone thats trying to ask for help. This is a place for learning and sharing great experiences about the best lifestyle in the the world-----"Boating"!
COMPRENDE-Dumbass
396
Yeah! what 396 said. I have gotten more help from these guys than anywhere else..............v-drive

[Back Forty]

dekmaster did you get anywhere..? Did you figure out the lock out problem?

[dekmaster]

I was away on buisiness so I haven't had time to fiddle with it yet, but I appreciate all of the advice.
thanks.

[Back Forty]

Let us know when you get it!