28SS prop questions
 

Hello all. I'm posting for my computer challenged friend. I've searched through the prop forum but don't seem to find the answer and I've found some posts here that create more questions (I know, don't they all?)

1976 28SS twin 5.7, trs. with cabin. It was running 23" pitch Mirage Plus BEFORE stroking engines. Now it's running at 5200 rpms, 69mph, and it's looking like a 25" Mirage should drop him another 400rpm.

We've heard a lot of talk about 3 vs 4 blade and are looking for advice. His interest is top speed more than stability. Our local prop expert seems to prefer the Mirage vs Bravo and doesn't seem interested in any other brands. His advice is to try a 25" and then a 27" and tweek the 27" to a 26" if needed.


He's a poor man with a rich man's boat and doesn't really want to buy an extra set of props if someone can help advise him. I appreciate any and all help and thank you in advance.

hydromotive or cleavers

24" bravo I

I Have 27 mirage's on mine. but i have 454 mpi engines if i remember it runs 74 mph at 4600 rpms

Years ago I had a 1974 28 SS. The best props were 23 pitch Hydromotive (3 blades) turning out. I had built two small blocks 355ci (425hp). The boat ran a solid 75mph on GPS around 5700-5800rpm.

The drives were TRS, but were factory mounted a little higher than most 28's I've seen. The top of the transom assembly was right up to the SS rub rail. The boat was originally rigged with the "Tempest Engine" package, thus the higher drive height.

He got to try the BravoI 24 and prefered his Mirage23. He hadn't heard of hydromotive and is checking them out and may have a chance to borrow some 25" Mirage. Thanks for the replies, he really appreciates it.

Call Tom at Hydomotive. He did mine 3 blade 24's.

His outdrive assemblies are also right against the rub rail. What was the "tempest Engine" package? Something he'll regret doing away with? Any additional information you could pass on would be appreciated. Maybe some insight as to what this boat does or doesn't like? Is there a manual or factory information available on his model?

Thanks,
Jim

As I recall, the Tempest package in the 28 Cig was factory rated at 395HP. It had Edelbrock Cross Ram intake manifolds with two 600 Holleys on a 10:1 compression 350ci. The engine manual stated 100/110 aviation fuel (leaded) required with the steel heads. The engines probably made more like 420HP with the Thunderbolt ignition.