TeamTalk

TeamTalk (http://www.mastercraft.com/teamtalk/index.php)
-   General Discussion (http://www.mastercraft.com/teamtalk/forumdisplay.php?f=6)
-   -   New engine, new prop? (http://www.mastercraft.com/teamtalk/showthread.php?t=55340)

svxwilson 06-21-2013 02:41 AM

New engine, new prop?
 
I just got my new engine installed and used it for the first time today. I went from a stock 351w with 210-240hp to a 300hp 351. The engine builders said do not take it above 4600rpm and should cruise under 4200rpm. At 4000rpm I am just barely getting to 30 mph. The old engine had similar results. It gets there in one hell of a rush. I have a acme 543 on it now. I have way more than enough bottom end so I can sacrifice in that area to get faster top ends. It has a 25/1 PCM gearbox.

ProStar Slalom 06-21-2013 08:11 AM

Quote:

Originally Posted by svxwilson (Post 949266)
I just got my new engine installed and used it for the first time today. I went from a stock 351w with 210-240hp to a 300hp 351. The engine builders said do not take it above 4600rpm and should cruise under 4200rpm. At 4000rpm I am just barely getting to 30 mph. The old engine had similar results. It gets there in one hell of a rush. I have a acme 543 on it now. I have way more than enough bottom end so I can sacrifice in that area to get faster top ends. It has a 25/1 PCM gearbox.

Something isn't right...either tach, speedo, or prop. No reason to be turning 4000 at 30mph, should be around 3000-3100.

jk13 06-21-2013 09:49 AM

Quote:

Originally Posted by svxwilson (Post 949266)
It has a 25/1 PCM gearbox.

You mean 1.25:1? That's a powerslot transmission and you have a prop for a 1:1 on there--and a low pitch one at that. My brother also has a modded 351 but he has a 1:1 transmission and runs the 541 (one pitch higher) with no problems at all regarding holeshot and top end. You are geared lower and pitched lower than he is.

Call Acme and they will get you set up with what you need.

Table Rocker 06-21-2013 09:53 AM

I am confused by the setup. Your engine is reverse rotation, but your prop is LH? Adding to the confusion, I found this on ski-dim:

3BLD LH PROPELLER 1" BORE
14 X 16 LH, SKI BRENDELLA WITH RH ENGINE RUNNING PCM 1.23:1 TRANSMISSION. THIS ONE'S FOR YOU!!!

I think I can safely say you need a steeper prop.

Okay, further reading shows that the PCM Model 40A transmission reverses rotation. I would guess you need that prop listed above. Most gear reduction props are going to have something other than a 1" shaft.

TRBenj 06-21-2013 10:09 AM

You are going to get better advice if you post somewhere where people are familiar with PCM powertrains. Try correctcraftfan.com.

svxwilson 06-21-2013 11:53 AM

I was running from memory and that was a bad idea. It is a 1.23/1 ratio. I just got off the phone with acme he recommended a 1793 which is a 13.5 /14.25 4 blade .105 cup. I think I am going to roll with that. The acme guy said if it doesn't work well he will let me return it for a full refund on exchange for another different prop.

svxwilson 06-21-2013 11:59 AM

It is looking like I will have a like new acme 543 for sale. I think I am going to pull the trigger on the new prop that is actually for my boats set up. The acme guy wasn't sure why they sold the previous owner the 543 as it wouldn't work that well even on my factory set up. My only thought was the old engine was so tired and wore out it needed that 543 to pull people up.

Spork 06-21-2013 05:31 PM

2 Attachment(s)
Quote:

Originally Posted by TRBenj (Post 949324)
You are going to get better advice if you post somewhere where people are familiar with PCM powertrains. Try correctcraftfan.com.

Plenty of PCM's in Mastercraft's

Sure looks like a LH to me and not RH

His LH Prop
Attachment 97260
My LH Prop
Attachment 97259

Table Rocker 06-21-2013 05:58 PM

It's his PCM transmission that is odd. Right hand rotation engine reversed to a LH prop.

svxwilson 06-21-2013 07:42 PM

Quote:

Originally Posted by [email protected] (Post 949520)
Plenty of PCM's in Mastercraft's

Sure looks like a LH to me and not RH

His LH Prop
Attachment 97260
My LH Prop
Attachment 97259

The correctcraft forum doesn't have nearly the amount of helpful people either. I have tried both.


All times are GMT -4. The time now is 11:27 PM.