Hello to all, great forum here

[bighead]

Hello, I purchaced a 1987 Commander open bow with a bbc and Berkeley jet with a place diverter 3 months ago and just love it. I found this site yesterday and have learned quite a lot of very good info from all the posts, thank you to everyone. My boat is a 21' open bow with a BBC that was built by Harmon Marine ? and has 325hp stickers on it, a cast iron intake and a 850 Holley carb, All I have done is a tune-up, new points cap wires etc, I set the points with a feeler gauge and set the timing so that it has 12 deg at idle and about 32-34 deg at 3200 rpm. With a full load of fuel and 2 adults and 2 kids with a loaded cooler I GPS'd at 54.7mph at 4300rpm, from what I have read this sounds OK? I am running 30wt valvoline racing oil but am considering going to synthetic mobil 1. This boat is super clean and I paid 6 grand for it which I think was a good deal and I am happy. Of course I want to go faster and realize this is one heavy big boat but would a few well selected mods like ignition and intake make a bit of difference or should I just leave it be and get a smaller boat to go fast in??

[BrendellaJet]

Welcome to the boards.
As far as going faster, you will want to make sure the pump is in good shape. Personally I would ditch the points, and upgrade to a pertronix set up or even an HEI. A new intake would be a good idea too, youll save weight and even pick up a few hp because of design differences. Headers would be next, but for the money, I dont think the purchase would be worth it for a covered engine(needs water jacketed headers $$$$). If you want to go really fast70 plus? your gonna need to open up that motor and change cam/heads and maybe more depending on the condition of your motor...

[bighead]

Ditching the points is on the list for sure and as far as the intake lets assume that those are the only things I will do for this season what would be the best choice. As for the pump it has a aluminum impeller and what little I know by reading the Berkeley info it appears to be i n top shape, no dings or gouges and no cavitation at all.

[mud duck]

Just have fun with it!!! 54 mph is plenty good, especially with kids and gear. At that rpm range you should be rock solid for many years to come. You can spend plenty of money on mods, but only get 10 hp here, and 15 hp there, and still go 54 mph. Put you money into gas and have fun on the water!! Your family will be much happier with you on the water rather than you stuck in the garage working on more mods.
I want to get back on the water damn it!!! :mad: Enough engine building, how about building memories. :D

[bighead]

Mudduck funny you should say that as the majority of the people I have talked to on the water have said the same thing!! I just want to go faster especially after riding in a Hondo

[napabob]

Originally posted by bighead
Hello, I purchaced a 1987 Commander open bow with a bbc and Berkeley jet with a place diverter 3 months ago and just love it. I found this site yesterday and have learned quite a lot of very good info from all the posts, thank you to everyone. My boat is a 21' open bow with a BBC that was built by Harmon Marine ? and has 325hp stickers on it, a cast iron intake and a 850 Holley carb, All I have done is a tune-up, new points cap wires etc, I set the points with a feeler gauge and set the timing so that it has 12 deg at idle and about 32-34 deg at 3200 rpm. With a full load of fuel and 2 adults and 2 kids with a loaded cooler I GPS'd at 54.7mph at 4300rpm, from what I have read this sounds OK? I am running 30wt valvoline racing oil but am considering going to synthetic mobil 1. This boat is super clean and I paid 6 grand for it which I think was a good deal and I am happy. Of course I want to go faster and realize this is one heavy big boat but would a few well selected mods like ignition and intake make a bit of difference or should I just leave it be and get a smaller boat to go fast in??
I also have a Harman marine Chevrolet 454 CID, 325 HP engine circa 1978 (8.25:1).
http://www.harmanmarine.com/newsite/Library/pp/01.pdf
http://www.harmanmarine.com/newsite/pp/index.html
When I purchased it in January 04 from my in-law it was a replacement engine for the original Hardin Olds 455.
I converted the dual breaker Mallory distributor, YL624AV2, with a Unilite conversion kit MAL-558 (photo optic trigger).
Replaced the cast iron intake manifold with an aluminum cast Edelbrock Performer 2 - O (oval ports). Idle - 5500 RPM range.
Removed the automotive carburetor and installed a marine Holley model 4150 750 CFM four barrel, mech. secondary, and electric choke.
All mild bolt on improvements were done while waiting on upholstery work.
Now I will enjoy it the rest of the summer.

[AngryJosh]

Welcome, looks as though you are getting plenty of good advice.

[napabob]

Originally posted by AngryJosh
Welcome, looks as though you are getting plenty of good advice.
VFW, Life member Post 9472, Danang '69-'70
U. S. M. C. (always)
Volunteer firefighter/EMT/Engineer,'88-'04.

[327,jet]

Sound's like you have a real descent running jetboat.A Edelbrock Performer is a real good choice for a add on. Light-weight and maybe even a little more torque. If your ignition is running good , leave it alone. I try to upgrade at least one thing a year on my jet. This way I can still make the house payment's and put gas in the boat . Welcome to the forum ,good luck with your jet.