stinger390

I'm wondering what combinations of power and prop sizes and pitch are working for the Stinger 390's out there, and performance figures to go along.

I'm still dialing in my 1985 model. Currently running 22P Bravo 1 props on about 420-450 hp engines, standard TRS / Borg Warner 72C drive system. I'm still setting up the engines and dialing in the carbs. I am wondering if I am overpropped for this boat as so far I can only get about 4400 - 4500 RPM and 55mph or so. I'm a long way from done with the engines but I'm wondering if I am asking too much of them with the 22p props on this boat. I know a new boat in 1985 ran 62 - 64 mph out of the box on stock 370 mercruiser cyclones. (maybe it was the 400 cyclones) I am hoping for better.

Any information about your setups is appreciated. (Maybe I should have left the twin 1000 HP blower motors the boat came with in there! This old girl hit over 100 MPH with them.)

Pictures of before and after engines......

Jons

If your 39 Stinger went over 100 M.P.H. with big motors it is most likely the fastest 39 Chris Craft Stinger ever built. Might want to put those motors back in. The props you have on the boat now slipping at 10 % would put you at 55 MPH. If you could spin current motors to 5,400 RPM would net around 68 - 70 MPH with same slip % Can you try smaller pitch prop. Your camshafts are they good for mid 5,000 RPM range ?? Good Luck

stinger390

I don't doubt that it was the fastest Stinger ever, however Chris Craft never dreamed that it would ever go that fast when they designed it I'm sure. If you throw enough power at anything you can get it to go fast. The doctor that owned it before me spent about $35,000 on engines and setup for this boat. It spun 28P 4 blades and cruised at 3800 RPM at 70 - 75 MPH. It was rev limited to 6000 RPM and would spin that easily. The acceleration was neck snapping for a big old boat like this. It had about 100 - 150 hours on the engines when I bought it and I thought they were just a couple of ticking time bombs. I found someone who wanted the big engines and he had factory 420's that I wanted that he had rebuilt and installed as part of our trade arrangement. The whole thing turned into a disaster and I am starting to wish I kept the other engines in there for a while. These are starting to come together now though.

I don't have other props right now to try, but I could get some for next year. I'm still trying to get the engines set up correctly and see what happens. The cams are low / mid-range, but the intake the guy installed is for upper range (single plane). I wish I was more proactive idurring the parts purchasing time, but what is done is done. I told him I wanted stock but that did not happen.

I was doing 55 the other day with one engine topped off at 4400 RPM and the other at 4100 RPM. I figure if I can get the rev's up to 5000 with these props I should see mid-60's or so. If the engines dont set up for that power than I'll have to try smaller props, perhaps mirage 21's or have these 22P 4 blades re-pitched for 20 to 21P if that is possible.

stinger390

I was reading a 1983 and 1984 report on this boat last night. It seems a 1985 model came from the factory with 15 X 19P cleavers. The boat did 62 with twin 400's. I'm thinking I over propped. I just bought a set of older 14 3/4" X 21P Mirage 3 blades to try. Should spin better and be easier on the drives. I guess I will see what happens.

Joyride

Your boat weighs 9750, my 375 weighs 9500 (dry weights). I''m running 4 blade Bravo 1 22p and getting about 60 mph (almost) at 4900 rpm WOT. I thought I could get some speed if I could get some more rpm by trying a 22p 3 blade. I ended up just spinning them. There wasn't enough blade surface area to get me out of the hole. So I've just decided to settle for 60mph.

Are those Sea Demon Carbs? I've got those, too. Our set up looks about the same. I have EMI Thunder exhaust. Supposed to be about 450hp.

I'm looking forward to see what you end up with.

stinger390

I'm surprised your 3 blades did not do anything. The boat came from the factory with 19P cleavers which I figure by todays standards were terrible for this boat with deep drives. I had another run today which gave me 4400 rt engine, 4100 leaft engine and 55 mph. If I can get the RPM's up a little more after I finish setting up the carbs I'm hoping for 60 plus. The boat went 60 with crummy props and 370 HP in 1985, I would think I could do better than 60 with nearly 420 - 450 HP and 23P 3 blades or 22P 4 blades.

Your engines look great. Very similar build to mine. I'm still tinkering though.( I guess we all are...right ) One of these days the setup will be finished. I'll just keep throwing money and wrenches at it until it is.

Todd

Mike's Stinger

Hey Stinger390 did you ever get it dialed in?

Stinger390X

Hi Mike.
That post was from many years ago from Todd the former owner of the boat. I own the Stinger now and it has twin 420's with stainless Mercury Revolution 4 blade 14/1/2” x 19P. The engines crank at around 4600 or so and the boat cruises along at about 59mph.
I can cruise easily at 3000rpm all day and move along quite nice at 40-45mph and not use alot of fuel. Anything over 3600rpm the four barrels open up in the carbs and she starts to drink fuel!

sting87222

Hey Stinger390x you got those rev 4 props i see!!!!! Tell me that boat moves better out of the hole now>>>> and i see your top speed is better to...... all and all for the engines you have i think that is the best prop for all around performance

kgz3

iTrader: (1)

i have a 1987 with new interior & exterior less motors that i would like to sell on tri axel trailer .it hasnt been in water since 1988 if interested call 309-925-4620 boat is in il.