327 performance

i have a 1967 tahiti jet boat with a 1967 327 hypo out of a corvette....came in the boat that year. right now it has edelbrock intake manifold and carbuerator from the 80's, im lookin to get a new carbuerator and manifold. i also plan to rebuild in the next few years....not enough money now. the engine never gets above about 4200 rpm because its limited by the jet. im lookin to get the most hp and torque possible out of a new intake manifold and carb......anybody have any ideas of what would be best for this engine....keep in mind its in a jet boat so being streat legal doesnt matter and it never gets above 4000 rpm so any power addes in the 5 6 7 grand rpm wont help, thanks a ton -scott

Seeing as you're limited to 4200 rpm, build for torque, torque anad more torque. Your hp numbers will follow.

The victor Jr. Manifold is pretty sweet, not sure however what the rpm range is, but it should work good at 4000, I'd imagine. Oh , and stay away from the edlebrock performer carbs, I know a lot of people that have had a lot of problems with them after a while. One guy I knew had a mustang and the thing screwed up from the inside and caught on fire....... didn't do much damage other than the carb, however.

im thinkin of a holley 650 double pumper and a victor junior manifold.....that sound like the best set up to anyone else out there???

Vette If your looking for a Victor Jr. Manifold I have a brand new one Part#2975 in the Summit magazine that I want to sell. I don't know if you would want this though since it makes its power from 3500-8000RPM.

I have a 1970 Glastron jet boat with a 327 in it it responded really well when I installed a Edelbrock Performer and a Holley 600 C.F.M. carb the carb has vacuam secondaries and center bowls also vent baffles . Next I am going to address the ignition . Write back please,good luck.

thanks, how fast can you get your boat up to ?? this one use to hit 60 mph...now 54 if im lucky, i really think its time for a rebuild but i just dont have the money.

If the motor needs a rebuild, I doubt if a new manifold and carb are going to do any good. If it were me, I would just run what I got and find another motor and start rebuilding it as money permits.

Tech and Dave have the right idea. Especially because the boating season is just staring. If you pull the engine now you'll miss most of the summer fun.

My little jet does around 60 with 93 octane, but with the price of gas it gets expensive to dump the four barrels.I,m installing trim tabs this year to try and keep the nose down.Does your Tahitti run high in front also?

yeah it used to, we got a diverter so we can control the angle of the boat more now....and it puts out a nice rooster tail:D

I think you should put a holley marine carb 650 CFM and a victor jr on it

There are a lot of people telling this guy to run single plane manifolds. I have NEVER heard of a single plane making more torque than a dual plane down low. I am not saying that they don't, but if some of you out therethink that they do I woud like to hear why. By down low I mean about 3500rpm wich is just about 500 under this guys limit.

whats a good dual plane manifold?

Ok, how about Holly street avenger builds from idle-7200 ( satin finish ) $125.99 Jegs price, Wieand Stealth idle-6800 ( satin finish ) 145.99 Jegs price, Edelbrock Performer off idle- 5500 ( satin finish ) 114.99 Jegs price. These are just a few well known manifolds and/or brands. Hope this helps ya out.

monte man shows his rear again not knowing what he is talkin about fire from the carb is in tha timing and btw eldelbrock holleys predaters etc all good carbs and your not really gonna see a whole lot of diff in a intake carb swap try the cam and heads then the carb and intake

Hey vette Edelbrock RPM Air Gap is the hot new ticket for low end torque it creates power in the 1500-6500 range and is supposed to run cooler which means more power.Also a good tune up might bring things back up to speed . check wires,plugs,ignition and fuel supply .It won't be long now boating season is just around the corner.

the engine is taken care of very well, new plugs and wires at the beggining of every season, timing is perfect, it still screams....i just want it to hit 60 again. i saw a hot rod show where they took a late 60's el camino with a big block and replaced the orginal holley and intake manifold with a new edelbrock intake and carb and it added 100 hp at the wheels. and the boat hit 60 with the holley double pumper we used to have, but when it went out we got a edelbrock 4 barrel and its never been teh same.

thats kinda out there vette adding 100 hp with a carb swap no way

they showed it on the dyno before and after.......now the old intake manifold and carb could have been waaaay out of tune or in need of a serious rebuild. but the el camino put out 190 hp at the rear wheels before and 300 after with a 454 i believe, maybe another size big block. i was pretty freakin suprised myself.

carb and manifold still that much i dont believe would have to see i would believe 50 or 60 not 100 what did you see this on..?

VETTE 1967 What make of jet unit do you have? but chances are you have worn tips on the impellors and /or a worn lining on the jet , a few thou clearance past nominal specs on the impellor tips
will reduce the available thrust and increase the rpm and of course reduce your top speed . so ask yourself just how much sand and other -rap has been dragged through it ,how many hours has it run ie maybe you are in the zone for a rebuild??????

i built a motor for my mastercraft , it was a 351 , i put 9.5 compression , use a cam that comp cams sold me , cant remember the specs. had the heads gasket matched , and a little bowl work . ballanced the whole thing . used roller rocker . a edelbrock intake and a 600 holley carb . and a msd ign .
the problem it was still a boat , the exhaust was too restricted.
but i went from 42 mph to 48 mph . then i changed the prop and went 52 . only help i can tell is talk to the cam company , dont pick it out of you head or someone else unless they work at a cam company !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
and listen to tech insp. and dave they know there shi$.

haha i dont exactly have exhaust restrictions, its not quite straight pipes...it goes through headers then these rubber tubes, but i dont think exhaust restrictions are and trouble for me. i know when i finally rebuild it im gonna build it for absolute power. bored it out, most extreme cam possible, ported valves new pistons, crank shaft, the works....anything possible to get hp out of it. the boats only used about 30 hours a year so i dont have to worry about longevity of the engine.

the jet was rebuilt 3 years ago. rebuilt berkley jet, diverter, gas tank, fuel pump....thats pretty much all hte boat has lol. i think the speedometer may be off......it is 37 years old. because a raced our waverunner that is a 1100 cc triple carb that freakin hauls ass, and i stayed right with it, top end it was a liiiitle bit faster. but the waverunner suposedly goes 62 so maybe my boat still does go 60 :confused:

i saw the carb/manifold that added 110 hp on horsepower tv, on spike tv....the first network for men haha

funny thats my fav channel specialy when trucks is on neways dont have to make me a believer could care less lol have fun with your boat and dont forget the tow straps

haha tow straps, after forgetting the plug last time:CRY: i wont ever forget anything again.

I still think a holley carb is the way to go , get one with jets in both bowls.This way you won't have to deal with metering plates. It sounds like your boat run's great,if you really want more speed consider a super-powershot from NOS. you can start out with 50 H.P. and move up if you need to . Also i've heard that a loader grate from Rex Marine will pick up around 5 M.P.H. on the water. JET ON !!!!!!!!

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Originally posted by vette1967
i saw the carb/manifold that added 110 hp on horsepower tv, on spike tv....the first network for men haha

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110 hp, right..........wonder were they hid the N2O :whacked:

ive always had nos in the back of my head, wont it be harmful to an old engine like this one? it is 37 years old without a rebuild.

Hey vette how's it going .If your motor is in top shape running N.O.S. should be no problem. If you have good fuel delivery and an excellent ignition , running a super-powershot from N.O.S. should be O.K. Start out with the 50H.P. flare jets and move up from there . All the guy's I know have had problem's with N.O.S. only when they got carried away with it .I am also considering it so let me know how it work's out .JET ON !!!!!!