Logo
FULL SITE MENU

454 cid new owner need help

T

teedles

New member
I just bought a 1987 Blackwatc

I just bought a 1987 Blackwatch 30 with twin crusader 454 cid engines. The model numbers are RH350 & LH350 with 615 hours each. The boat did not come with props and I need to get some help finding out what the wot rpm's might be and any help on other details before making the right choice on props. Any thoughts?
 
"I bet I can answer every ques

"I bet I can answer every question you come up with over the next year...

You should have the 1.5:1 gears. The OEM configuration delivered them with 18x17 3 blade wheels with the 240 gallon tank. They are fine if its still in the factory configuration.....

If there's a hard top or a half tower, I'd suggest going lower.

The WOT range should be 4000-4400.

I'd suggest going to a "PropScan" shop. Their products are superior when delivered and service is superb."
 
"Wow, that's good info! T

"Wow, that's good info! The boat does have an aluminum tower and 4' bow sprit. What do you mean by going lower?"
 
"I spoke to the previous owner

"I spoke to the previous owner, who said he had 17x15 props that did 27 knots at 4100 wot. Is it better to go with a larger dimension and more pitch than he had? like 18x16?"
 
"did he tell you what the load

"did he tell you what the load was and how much fuel to get the 27 knots?

I took 1.5" of pitch out of mine after the tower was added. Depending upon how you plan to load it up, the 18x16's would be fine (if you're on the light side).

Do you know which core material is in the hull?"
 
"Is it better to go with a lar

"Is it better to go with a larger dimension and more pitch than he had? like 18x16?

Everything else being equal, the larger diameter wheel is better as long as you keep 15% or so of diameter as tip clearance to the hull. You are at 4100WOT, light? You want to target 4400 WOT light. A bit less pitch. If 4100 rpm at heavy load, then OK."
 
"There's plenty of room wi

"There's plenty of room witht 18" wheels.

The 15.5" pitch on our setup would yield 4000 RPM (WOT) with full fuel, water, 8 men, and two full mongo coolers - in mid-August, too."
 
"Thanks diver dave. I always

"Thanks diver dave. I always wondered whether to measure my WOT at light load or heavy load. Now I know. I get 4400 at full tanks so I will go up in pitch to 19 x 17. 17 being the pitch.
proud.gif
"
 
"A couple of Blackwatch guys,

"A couple of Blackwatch guys, who knew??
I never get questions from Cary 32 owners, so few left..."
 
"I don't think the BWs out

"I don't think the BWs outnumber the Cary's by much, if any. How many Cary's were built, DD?"
 
"They built a 28' and a 32

"They built a 28' and a 32' in the old days. I heard that the original owner sold in '73, the year my hull was born. Now, apparently still alive, they make the 50', not sure about the 70'. Much different clientel. Still in Miami. A great hull for what I do, with its aggresive V hull, for blasting across the gulf stream. Not so great for last w/e drifing for swords."
 
"I found a thread on another b

"I found a thread on another board where Cary's son had posted and added some other history about the line. I fished on an older 50' version down in teh keys one winter - very wet while drifting or anchoring. apparently there were a few in-between versions, too, at least per that thread.

Al - are you referring to the "rare" attribute because the 34C's are not "cooked" in an autoclave?"
 
"Being "relatively: inexpe

"Being "relatively: inexpensive for a sedan style cruiser in the 1980's , there are probably more Silverton 34C's around the area here than any other boat... really not that rare...."
 
Back
Top