View Full Version : Refreshing a 351 Ford, PCM 240hp

old 86er
03-29-2009, 07:35 AM
I'm new to the forum. I have a 1986 MC, 351 Ford PCM/240 hp, holly 600cfm, with 1400 essentially bulletproof hours. I am diligent re oil and filter changes every 25 hrs (MOBIL 1). Its time (I think) to work around the edges to keep max performance as long as possible. I have an electronic ignition kit that I need to install. Other than that, I am open to suggestions. What do you recommend re plugs and wires? Other things?? thanks.

03-29-2009, 08:02 AM
Here's some links to get you started, http://www.tmcowners.com/teamtalk/showthread.php?t=3533&highlight=electronic+ignition and http://mastercraft.com/teamtalk/showpost.php?p=166941&postcount=33
Your MC dealer and http://www.skidim.com/ has tune-up items too.

03-29-2009, 08:30 AM

03-29-2009, 09:47 AM
"an oil change every 25 hrs is a waste of oil and money, not to mention the disposal of it but that is your biz. Point is that an oil change should be good for 75 - 100 hours, depending on factors of oil concerns. I change mine once a season and run the same 75 - 100 hours in a ski season. I just changed mine last weekend for de-winterization and it looked clean and unused after about 90 hours last season. Everyone has their own agenda."

25 hours is a waste unless the motor has blow-by or some other problem that causes the oil to become loaded faster but 50 hours isn't a bad number. Many don't put more thna that on ehtir motor in a season and since oil becomes more acidic after use, it's never a good idea to leave it in for a long time, unused. I would never recommend leaving it in over the winter and it can pit/etch all kinds of parts that can fail after years of this.

"The electronic conversion will be the best $150 you can spend on an upgrade. Be careful when you take it apart and watch for springs and weights in the bottom of the distributor."

I agree, mainly because it adds consistency to the motor's operation. The days are gone, of people knowing enough about points ignition systems to putz with them on a regular basis in order to keep them running properly. Some still do, but the vast majority of ski boat owners don't want to work on the boat before taking it out. Also, people with that kind of distributor need to make sure the weights and springs are still functional, especially if the boat hasn't been running well and it had recently sat for a long time.

"Keep your tranny clean and do clean the strainer seasonally. I find slivers and shavings every so often but find less and less as the tranny gets some age on it."

By 'strainer', I hope you mean the transmission fluid filter and not the oil cooler *which should be checked a lot more often than once per season). Seeing some shavings is normal, so people need to know this.

03-29-2009, 09:54 AM
In addition to all of the previous posts and suggestions, I updated my 79 351 with 1200hrs and pretty much found there was nothing more to do other than the timing chain was pretty much on its last leg. It cost around $25 and was worth it.

03-30-2009, 12:23 PM
Depends how involved you want to get. I did a cam swap, new intake manifold and had the worked on heads over the winter last year. Also put in new timing weights and springs. these engines respond really well to a few basic upgrades. I'd estimate my engine to be somewhere in the 325 hp ballpark.

Stock intakes were really restrictive. There's a clean-out plate underneath the stock intake manifold. On a 20 yr old boat, could def use a cleaning.

WFO MasterCraft
03-31-2009, 11:08 PM
I am rebuilding my PCM 351W right now. What will my 1.52:1 Velvet Drive handle as far as HP and TQ.

east tx skier
04-01-2009, 12:43 PM
I am rebuilding my PCM 351W right now. What will my 1.52:1 Velvet Drive handle as far as HP and TQ.

Quite a bit, I imagine. Start with a CNC'd prop, GT40/GT40p heads, and new intake will get you to a good place. New cam and work on the combustion chamers for a better compression ratio might not hurt either. But start with the prop.

04-01-2009, 02:06 PM
:rolleyes: just like eastie said :rolleyes:

04-01-2009, 10:47 PM
I am rebuilding my PCM 351W right now. What will my 1.52:1 Velvet Drive handle as far as HP and TQ.

You'll have a hard time and need some deep pockets to build up your 351 with more power than the transmission will handle. They are pretty tough.

04-07-2009, 11:53 PM
Don't forget to change the impeller. All these other upgrades will go up in smoke with a bad one and a distracted driver....