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Hey guys,

I've been running the delta with the sst 60 again this year. It is a great combo! Im using a 12.5"×24 pitch ron hill cleaver. It runs a solid 70-71.5mph most passes, and ive had multiple passes at 72.1mph. I would like to get it up into the 75mph ball park as it handles extremely well at just over 70mph. I have not played with engine height at all other then day 1 with the sst60.

For those of you with 75mph+ race hulls, What would my best course of attack to get more speed out of it? Ive been wanting to get the prop worked but havent gotten to it yet. Im currently running about 9%-10% slip, id like to see that drop to roughly 5% if possible.

Should i be doing work to the motor? Get my prop worked? Try to find a taller prop?

That is good speed for a boat that was designed for to do mid 60s. My Delta with a mod 56 does 68 with a Ron Hill cleaver. I know there's more in mine but needs a bore job and 3 pistons. If you're happy with Ron's cleaver, why not buy another one from him and send out the slowest one to get worked on.
Just a warning, the Delta can pack a lot of air over 60, I know, I stood mine on it's transom last year probably doing only 60- 62, it reminded me to be extra careful.

Where are you height wise now? Any set back?

What kinda rpm turning? How is the compression?

Ill have to double check what height im at right now. Im running one of Hevi Kev's setback brackets.

Yesterday it was swinging about 6400-6500 as it was hot and humid. When its a bit cooler and drier, it usually spins 6600-6800 depending on trim. Compression last year when i got it was 160lbs across all 3

All of the plus 75 mph T850 boats are race prep production block or oval port fishing motors running nitro gear cases and very costly multi time reworked props.
Pure SST60 motors with the normal 180 compression run 72 to 74 on a T boat. Mike Hooper has a Critch and a VooDoo running in that range. Craig Fraser and Dave Whittington both ran 160 compression SST60's and they were running in the 68 to 70 range. So you are running well for the combo you have. The problem with the SST60 on a V hull is the load on the prop. SST60's were designed for a tunnel and like to turn 7500 to 8400 rpm. The power curve horsepower really drops in the high RPM range. The porting allows the motor to rev higher. On a tunnel there is less drag on the prop and less prop in the water at top speed. There is much more load on the prop on the V hull so the motor does not rev as high compared to the tunnel. Some will run 11 3/4 x 21 with the SST60 on the V hull to get the RPMs up. There is a big difference in the life span of a motor turning 7000 compared to 8400.

Here's an SST60 on a tunnel.. At 77-78 mph it is turning over 8000.
https://www.youtube.com/watch?v=LHsrilzxVBM&t=197s

Here's an oval port on a T850......Jake is only turning low 7000.s
https://www.youtube.com/watch?v=wU2zON-6xsE&t=44s

Now listen to the sound of your motor compared to the tunnel...much lower RPM
https://www.youtube.com/watch?v=WhzzmiAT7ZQ

At 8200 plus RPM...the SST60 is much quieter compared to running 6800 to 7900 where they have a noticeable bark.

Now this is Sam's SST60 which has the SPECIAL only for a few Mike W. sleeves. These sleeves changed the powerhead from being spiky to having a flat power curve that produced the same hp from 6800 to 7900. They turned a little less top end RPM compared to some of the high rev motors, but they had much better punch off the dock and better mid range.
https://www.youtube.com/watch?v=TziQtCLtoTw

That was my dad running it for the first or second time, I think he only had it up to like 6000ish rpm on the video. I've taken this motor to 7500 or 8000rpm I can't remember which. I was turning an 11×23 cleaver but it didn't push me anywhere fast.

If I need to start porting it to go faster I will probably hold off. I've got no time to put into tearing it down and when I'm free of rather drive it haha. I've got a Valero that needs to be finished, so the delta at 70-72 mph may have to do for now

I wouldnt go chasing any more speed on a delta. That's a phenomenal speed! Congrats

Do you require lots of trim? I hope not - and consider mods that keep it that way if you do try and get more speed yet

Jetting? timing? Fuel?

Just my 2 cents.

I bet there is a couple more mph in that prop. I would have it checked. You should be able to run 72 jets and that should get the motor running 72 on warm days and 73 in the fall. SST60 gear cases have a larger skeg and you can run the top of the prop shaft parallel to the bottom. As Jake mentioned avoid positive trim....you are well over the safe limit for a Delta...we saw a big change in T850 with the boats FLYING off waves when running over 73-74. Kevi's flip at Gravenhurst is a good example of the boat taking off....ALL of the plus 75 mph T boat drivers say their boats are much more touchy at top speed and they need to have the boat balance PERFECT!

I run very little trim, it appears to be right around neutral trim. Havent played with jetting or timing yet. Im running 91 or better octane super mixed at 32:1.

I do think there is more in the prop as well, but id hate to lose speed by getting it worked and being down if i wanted it worked right now. Id love to grab an omc 12×23 cleaver as it was .5 mph faster then my ron hill 24 cleaver and the omc cleaver was well used (had a few small marks in it).

I had eye'd up the engine height last night. The tip of the bullet is right about even with the bottom of the pad. I will have to put the level on it next time

take it to top gun.....