Dean O' Banion

I have a 1964 oldsmobile 98 with the 330 HP 394 Sky Rocket, and it has an aftermarket edelbrock 4bbl. on it. I am looking to put "three deuces" on it, and I know offenhauser makes a tripower manifold for the 394. Before I start really planning or buying stuff for this, I just want to know what I'll be in for.
I'm new to this, so I want to know if I can just put the new intake and carbs (hopefully Stromberg 97's) on and tune them just right and be all set, or do I need a new cam and all kinds of other stuff? How much of a power increase would I be looking at with the three two-barreled set up? If anybody has any experience or advice or warnings here, please let me know.

Oldsmaniac

I guess it would be easy to get the carbs and manifold but the first thing I would be sure of is that the linkages can be gotten to hook everything up properly. You should be able to swap everything over without any engine mods because I think this setup too only operates off the center carb until the gas pedal is pushed way down.

Dean O' Banion

Thanks oldsmaniac! Now that I know it's within my capacities, I'll start finding out about linkage and slowly start piecing together the stuff I'm going to need.
They're making Stromberg 97's again but at $450.00 a pop I'm going to have to find used ones some place and fix them up. Apparently they are pretty simple carbs so hopefully this will be doable.

59-59-59

Heres your first warning. I forgot if I read or heard ( research this for yourself to find out for sure ) that hood clearance is a major issue, and the tri carb Offy intakes (where the carb mounts) sits higher than a 4bbl manifold. Check if anyone else has done this swap, what carbs they used, what year car its sitting in, how much of a pain it was to hook up the kickdown, and what proven performance increase ( if any ) they experienced. What carb do you have on there now that makes you want to change to a tri carb setup?

Olds64

I agree. One of the biggest obstacles will be modifying the linkage on the center Stromberg to correctly operate the throttle valve of your Slim Jim transmission. The throttle valve setting is CRITICAL. If it is done incorrectly you can destroy your transmission.

Dean O' Banion

I have a pretty new 4bbl. Edelbrock on right now...That's just it, I'm not an expert on carburetion, I'm asking if switching to tri carbs will be worth it.
I figured if I got a noticeable boost in horsepower and it looked cool and period correct, I'd definately do it. However, if it's going to be some huge hassle and I'm not going to notice a difference, I'll just leave it alone.
As far as linkages go, I've looked around and there seems to be quite an array of linkage parts available for Stromberg 97's, including linkage sets designed for a tri-carb setup.

-Mack

mugzilla

The reason everyone has 4 bbls' is that they produce more, reliable H.P. ...

Oldskeeper

I plan on wrestling one of these under the hood of my other convertiable,not to gain horse power but to lean out the gas and see if running on a 2bbl works.The 394 in this rag top has a starfire engine and likes to drink the gas,if it works out I plan on changing the base of the breather to fit all of the carbs and keep the top the same.
I allready have the GM carbs from an aftermarket edelbrock 371 manifold and found a company at Carlisle that carries the 394 manifold.
Its on my list of things to do now.

Oldsmobomb

(Disclaimer - I have never owned a tri-power set up)

Having said that, it's time for a reality check. One of the benchmarks for factory tri-powers was the '66 GTO. Quoting factory numbers, it made 360 vs 335 hp at 5000-5200 rpm. That is not an rpm that is often reached unless you are racing or at WOT. Plus, Pontiac used a much different cam in the tri-powers and that contributed mightily to the revised hp figures.

So ... If you are thinking that bolting on a tri-power is going to be the shizzz, you will not notice much if any difference at low and part throttle operation. Even at max hp output, up around the 4800-5000 rpm range, you will not get a whole lot more than 5-10 hp boost, unless you are going to change the cam, cam timing, and most likely do some porting and relieving on the heads.

What you will get for your trouble are some cool noises, and a substantial reduction in gas mileage if you keep your foot in all 6 throats. If this is what you are after, then go tri-power. But on a big barge like the full-size Oldsmobiles of the 60's ... tri-power is chasing your tail, IMHO.

Oldsmobomb

p.s. - as stated, the linkage adjustment for the slim-jim is a very real consideration/problem

Dean O' Banion

Thanks very much for the reality check, as a matter of fact that's exactly what I was looking for.
If I'm not getting any substantial performance increase, then I'll forget about the idea. I admit much of my inspiration came from stories of my old teacher's untouchable 394 hot rod, but that was a totally different transmission in a totally different car, and it was 45-some-odd years ago.
Some day when I have plenty of money and time and a nice garage (wishful thinking) maybe I'll build a real hot rod and maybe come back to the tripower idea.
For now, however, I'm glad you guys have saved me a headache and a lot of money for a project on this particular car.