Gear ratio

The Main Sand Box for bertram31.com

Moderators: CaptPatrick, mike ohlstein, Bruce

Post Reply
User avatar
STraenkle
Senior Member
Posts: 230
Joined: Jun 30th, '06, 07:18

Gear ratio

Post by STraenkle »

As some might know I am getting new (to me) gas engine, Question is I think the original gears are 1.5:1 is that right for 454's with BW gears? I tried to look at the gears, but no markings or plates. Too Much paint and years on them
Scott Traenkle
User avatar
John F.
Senior Member
Posts: 2102
Joined: Jun 29th, '06, 07:58

Post by John F. »

Scott-

Almost positive that's what mine are. I'll check this week when I can.

John
User avatar
Harv
Senior Member
Posts: 1184
Joined: Jun 30th, '06, 23:59
Location: Brooklyn,NY
Contact:

Post by Harv »

Mine were 1.56:1 to be exact.
Harv
User avatar
STraenkle
Senior Member
Posts: 230
Joined: Jun 30th, '06, 07:18

Post by STraenkle »

Thanks guys, I was pretty sure it was 1.5:1, however I just talked to Eddie Johnson and he wants to put 2:1 ZF gears and run a 22x20 prop on the 1 3/8 shafts. Bruce or anybody else have feelings about this set up?

I thought I would be running a 1.5:1 and keep the same 19x19 props I have, but he does not have 1.5 gears only the 2:1. I am sure he knows these set ups better than I, but if anyone has issues as to which might be better, or is it half dozen one way and 6 the other I would like to hear.
Scott Traenkle
User avatar
CaptPatrick
Founder/Admin
Posts: 4161
Joined: Jun 7th, '06, 14:25
Location: 834 Scott Dr., LLANO, TX 78643 - 325.248.0809 bertram31@bertram31.com

Post by CaptPatrick »

Scott,

With the added horse power & torque of the 496s 2:1 gears are probably right, (talking out of school here...), but there's no way that you'll swing a 22" diameter prop under a B31. Sure you didn't mean 20x22 ?
User avatar
Bruce
Site Admin
Posts: 3785
Joined: Jun 29th, '06, 12:04
Location: Palm Beach Gardens, Fl.

Post by Bruce »

For my tastes, running a 22x20 props on a 1 3/8 shaft is a no.

Okay for the 1.5:1 which would run a smaller prop.

But you'll never fit a 22" prop under standard length struts.
User avatar
John F.
Senior Member
Posts: 2102
Joined: Jun 29th, '06, 07:58

Post by John F. »

Scott-

My friend's '04 31 Tiara had 496s with 2/1 gears and turned pretty big wheels--but on 1 1/2" shafts. That boat also had the 385 hp 496s, was a little bigger and heavier than our 31s (although with slightly less v), and turned up to about 38 knots. You'll have a 40 knot plus B31 easy--careful.

John
Bill Mckinnon
Senior Member
Posts: 117
Joined: Jun 29th, '06, 13:17
Location: Charleston SC

Post by Bill Mckinnon »

Those are the right gears for the 454"s. Just toke the 454' out of the boat and now have four gears to spare. If anyone needs some let me know


Capt. Bill
User avatar
Capt Dick Dean
Senior Member
Posts: 336
Joined: Dec 17th, '06, 15:33
Location: Long Island, N.Y.
Contact:

Coming clean.

Post by Capt Dick Dean »

This is just about good as any time to unload the truth about the Irish Wake. You remember her, she went aground last yr in Shinnecock and has been on a lot of sand bars prior to that one. Dam near a sand bar a yr. I also have to own up to the speed of the boat that was always thought to be fast. That was what I led people to believe. WOT gives 28.5 kn. Even with the hi-tech air filters and profomance plugs, a clean and smooth bottom.

The reason for the download now is likened to the criminal that just has to tell some body. Like the cops. That he commited the crime 20 yrs ago. I can't go on any longer.

Let me say that when I was buying the boat in 1998, I asked the salesman how he knew that the boat had big blocks. ( Big blocks to me are 454's). He said he just knew. He could tell. It troubled me that a 325hp sticker was on both engines. Well, having a sail boat for 20 yrs, what do I know.
The truth came to me a couple of yrs ago and really hit hard. I am still suffering. It started with an oil leak in the bilge. I found the source at the oil filter on the engine. Yeah, it was the seal from the oil filter housing connecting to the block. At the Mercriuser store, the parts guy show me pictures of the 454's. But my set up didn't look like that. So it was recomened that I go and get the serial #'s off the block which I did. As I was reading the #'s over the phone, the parts guy stopped me cold. My # started with a 3. 454's start with a 4. I gasped for breath.

"What yr is the boat?", he asked.
"1972", I replied
"You got a 427. 454's started in 1973"

I got screwed. I had to tell somebody a month or so later. So I told Capt Harv. You know him from fishing in Jersey. I made him promise not to tell anyone especially the 31 group. He promised. The last summer he tells me that Capt Patrick knows. And for some time.

"How the hell does he know?"

"Wasn't he on your boat in Montauk helping with a starting problem four yrs ago."

"Yeah, he was."

"Well,do you thing he didn't notice with the 325 sictker on each engine? He never said a word, did he? And he never said a word when you were shootin' your mouth off all this time. Geez, you went on and on for yrs, So I didn't tell him!"

"Boy, do I have egg on the face."

"You got egg all over you!"

Boy, I feel better. A load is off my weakened old frame. I feel can live again ....

See ya at Montauk.
A/K/A El Gaupo
User avatar
ScottD
Senior Member
Posts: 145
Joined: Jun 29th, '06, 17:25
Location: Palmetto,FL

Post by ScottD »

Dick, I bet you find that the 427's have a lot better resale value than the 454's. It' may not be a bad thing after all.

ScottD
User avatar
Harry Babb
Senior Member
Posts: 2354
Joined: Jun 30th, '06, 21:45
Location: Fairhope Al
Contact:

Post by Harry Babb »

Dick
Just say 3 Hail Mary's and you'll feel better tomorrow....

Harry
hb
User avatar
In Memory Walter K
Senior Member
Posts: 2912
Joined: Jun 30th, '06, 21:25
Location: East Hampton LI, NY
Contact:

Post by In Memory Walter K »

Dick- We still love you...and you probably would have still run aground on your way to Montauk no matter what engines you had. Walter
User avatar
CaptPatrick
Founder/Admin
Posts: 4161
Joined: Jun 7th, '06, 14:25
Location: 834 Scott Dr., LLANO, TX 78643 - 325.248.0809 bertram31@bertram31.com

Post by CaptPatrick »

And see? I still ain't said a word.... Don't fret, Dick, I still tell people I have lewd thoughts about sexy women, when it's really just the memory that I have. And I think I may have just misplaced that. Opps, nope, there it is!
User avatar
scot
Senior Member
Posts: 1470
Joined: Oct 3rd, '06, 09:47
Location: Hurricane Alley, Texas
Contact:

Post by scot »

Depends if you want to spend more money. The 1:5's will work fine.

The 2:1's will swing larger dia props = more efficient. A bit slower, but the boat will have less % of slippage with the larger wheels. The boat will also be less effected by sea state with the 2:1....meaning the varing loads on the engine will not be as dramatic.

Now go do the right thing???
Scot
1969 Bertram 25 "Roly Poly"
she'll float one of these days.. no really it will :-0
Tony Meola
Senior Member
Posts: 6940
Joined: Jun 29th, '06, 21:24
Location: Hillsdale, New Jersey
Contact:

Post by Tony Meola »

Dick, look at it this way, they could have been the Chryslers. At least they ar GM's and at the time they were built, they were the big blocks.
User avatar
John F.
Senior Member
Posts: 2102
Joined: Jun 29th, '06, 07:58

Post by John F. »

I don't see any reason to apologize for 427s...that's why Irish Wake is so fast.
User avatar
Capt Dick Dean
Senior Member
Posts: 336
Joined: Dec 17th, '06, 15:33
Location: Long Island, N.Y.
Contact:

Post by Capt Dick Dean »

Scott,
I didn't mean to hi-jack your thread. Just had to get it out. And I thank everyone for the kind words. You really think 427 have better or just as good value. I thought I just lost 10 grand.

But to answer the question, I have Velvet drive series 72c w/ 1:1.5. Had 18x18 Michigan quads and just last yr took an inch of pitch out. Was turning 3500 rpm and now with the 18x17 wheels get 3950 rpm's. Boat feels like it's not lugging. Engines sound better @ 3000rpm. I may still be over proped.
A/K/A El Gaupo
jspiezio
Senior Member
Posts: 882
Joined: Nov 25th, '07, 07:21
Location: Long Island, NY

Post by jspiezio »

Capt Dick Dean wrote:Scott,
I didn't mean to hi-jack your thread. Just had to get it out. And I thank everyone for the kind words. You really think 427 have better or just as good value. I thought I just lost 10 grand.

But to answer the question, I have Velvet drive series 72c w/ 1:1.5. Had 18x18 Michigan quads and just last yr took an inch of pitch out. Was turning 3500 rpm and now with the 18x17 wheels get 3950 rpm's. Boat feels like it's not lugging. Engines sound better @ 3000rpm. I may still be over proped.
Plenty of Corvette guys would be willing to buy them if you wanted them out.
Kurt Weber
Posts: 8
Joined: Dec 6th, '08, 19:03
Location: Hondo Tx

Post by Kurt Weber »

454's are basically a 427 with a little more stroke. the 427 is internally balanced vs extrenally balanced for the 454.
pro and con for both...
biggest difference is displacment... like 327 vs 350 in small blocks...
both can make good power and a few cid has little effect.
IIRC, the engine blocks are same with the crank, flywheel and harmanic balancer individual to the 454. 468, 496 and 502 are all larger versions (bore and stroke) from the 454 layout.
User avatar
bob lico
Senior Member
Posts: 5276
Joined: Jun 29th, '06, 19:22
Location: sayville,long island

Post by bob lico »

ok dick because you are my friend i will clear this up:forget serial numbers i can punch in anything you want.the real deal is the engine casting numbers looking from the rear of the engine looking foward the casting numbers are on the left top of engine.here goes 3869942 you get free mercruser 454. 3904351 is winning the lottery you get yanmar.if the front right cylinder block is marked je follow by 7 numbers you get the yanmars and bruce to install them!any other numbers are no big deal how ever 427 has forged steel the 454 in the hp range that you find in a bertram is cast iron junk and so are the cylinder heads.
capt.bob lico
bero13010473
User avatar
bob lico
Senior Member
Posts: 5276
Joined: Jun 29th, '06, 19:22
Location: sayville,long island

Post by bob lico »

should read forge steel crankshaft.
capt.bob lico
bero13010473
Post Reply

Who is online

Users browsing this forum: Bing [Bot] and 299 guests