View Full Version : High Perf Studies

09-07-2005, 05:04 PM
I know all you hi-perf Stude nuts are racing your cars but I have a question for you. I have 3/4 ton Studebaker 4x4 that I use for towing HEAVY loads. I didn't realize it but I had about 12,000 lbs behind it last weekend. I'm sure a Stude V8 can handle it. What do you think? Here's what its got: 289 bored .030 over, aluminium intake w/ carter AFB, ported & polished heads, stock valves, supposed R2 cam but it seems too wild, advanced timing and a Rajay Turbocharger. When I'm towing a load uphill I can't seem to get more than 3 or 4 lbs of boost. It also acts like its missing and I think maybe I have it too far advanced. It will also detonate when under a load. It used to ping until I put water injection on it, but know it detonates. I'm running premium 91 octane fuel. I don't know what to think. This is a 4x4 with about 18 inches of lift from a stock 2x4 height and 37 inch tires, but I think the performance should be better. If anyone has suggestions or can help me I would appreciate it. Thanks.


09-07-2005, 05:13 PM
Oh my God....[:0]:D:D:D:D

Lotsa Larks!
K.I.S.S. Keep It Simple Studebaker!
Ron Smith

09-07-2005, 05:25 PM
I dunno about your exact question, but you are probably closer to the limits of the Stude engine than anyone else on the planet according to your post! Now Ted has a lot more boost going through his motor, but he only uses it 1/4 mile at a time...


55 Commander Starlight
62 Daytona hardtop

Mike Van Veghten
09-07-2005, 05:46 PM
What's your gear ratio in the rear? With that big a tire and a high ratio...you're asking for trouble.
Not that you have....but "many" forget to put a lower gear ratio in when installing large tires. That'll kill everything.

You can always retard the timing a degree or two. What compression does the engine have? Somethings wrong somewhere if you can only get 3 or 4 lbs. of boost!

I watched a Pantera at Bonneville years ago... The car would only go 125 (or so) mph. It was noticed that a small vacuum line came off the carbuter. That fixed....he went out and came back with a 202mph timing slip!

09-07-2005, 07:19 PM
There are to many variables to diagnose what's wrong without seeing the truck but, Rajay is an old turbo have you rebuilt it or at least put a new cartridge assembly in it? What model is it a 300 D, E or F? Who sized it or did you just buy it used and bolt it on? I just retired from Garrett Air Research after 25 years in Research and Development at the Torrance plant. The most often problem I have seen is people using the wrong turbo for the application. On the cam you should use a cam that is the same on both intake and exhaust cycles and short in duration for heavy loads, Studes just don't like big cams. I could have more to say but I don't want to get long winded till I have more information.

09-07-2005, 08:04 PM
Thanks for quick response. My gear ratio is fine, I'm running 5.38 gears with the NP 540 OD. My compression ratio is about 9:1. The turbo is 301 E with a .7 a/r ratio. My dad bought it 30 years ago and set it up on the truck as an experiment. I put a new turbine blade assembly in it a few years ago and its tight. Its waste gated and the exhaust pipe from the turbine section is 3 inch running out to the rear axle with no muffler. It also has R3 headers if that makes a difference. I have obtained 10 lbs of boost in the past and the truck ran great when I put 100 octane leaded AV gas from the local airport. I'm also wondering if the water injection is coming on too soon. I think it kicks in before I'm getting boost. This is also trial and error on my part. I pulled about 10,000 lbs. over Donner Pass when I first put the water injection on.

09-07-2005, 08:24 PM
Your .7 a/r ratio is fine, the few things that would cause you to lose boost are gasket leaks or holes in the exhaust system, worn valves or rings, the butterflys on the carb does not open completely, a restriction in the exhaust system ( muffler or dented pipes), or a dirty air cleaner.

09-07-2005, 08:56 PM
My dad rebuilt the engine and it has low miles on it so I think valves and rings are ok. I don't see any exhaust leaks, its a straight through pipe and the air cleaner is fine. The carb is also working fine. My dad has a 63 Avanti R2. The carb works perfect and the cam is great on that car. I put his carb on my truck and it still ran the same as it did before. I'm wondering if the source of my problem is the cam.

09-07-2005, 09:44 PM
The only other thing is damage to the insides of the turbo $$$

Mike Van Veghten
09-08-2005, 10:26 AM
Well, if everything is perfect............you shouldn't have a problem.

What would be wrong with the cam? Stude cams are mechanical in nature. All you have to do is listen. If there is a ticking sound, there is a "possible" problem. If no loud ticking is heard...and the valves are adjusted correctly, no problem. If it needs adjustment and you haven't yet, it will run rough, idle slightly rough. Maybe give that a try.
Some may disagree, but with what you are doing (the turbo), unless you have installed hard exhaust seats, your exhaust valves will need adjusting more often than your intake valves. Even if you did install hard seats....when was the last time you checked the valve adjustment?

If the cam is going flat, the valves/rockers will make noise, if a lifter is abnormally wearing, it'll make noise, if a pushrod is bent, it'll make noise.