Powerboat Forums at SpeedWake banner
Cancel
Create thread New Forums

need input from the "smart" guys

4 reading
Jump to Latest
21 - 38 of 38 Posts
#21 ·
I agree if he has the $$ and wants to pull the motor and disassemble it to have someone check everything in his combo out he will be able to optimize his combo. Not knowing his budget and willingness to tear it all apart some tuning tips and ideas are the best place to start. Wouldn't it be cool to find that he is running 30 degrees of timing and his motor really loves 38!! He may find his RPM without spending a penny. If he just built this motor and is on a budget I am sure he is willing to try some things before just throwing in the towel in my .02.
 
Discussion starter · #22 ·
You are all exactly right, and this is what I've told him since he first asked me the quesrion. It's unfortunate that guys that put this kind of $$ and energy into a project inveriably find themselves disappointed in the outcome. They either think they can't afford to have the heads flowed, or can't afford a custon cam, (or get told it's a waste of time) yet, like CFM said, then they spend how much trying to bandaid the combination "throwing" things like TR's and props and gears, then some guy says it's the wtrong cam "I ran this X brand and it worked great!" (how many times have we heard this) Thanks to all for all the useful input, and the re-enforcement.
 
Discussion starter · #23 ·
WETTE VETTE said:
I agree if he has the $$ and wants to pull the motor and disassemble it to have someone check everything in his combo out he will be able to optimize his combo. Not knowing his budget and willingness to tear it all apart some tuning tips and ideas are the best place to start. Wouldn't it be cool to find that he is running 30 degrees of timing and his motor really loves 38!! He may find his RPM without spending a penny. If he just built this motor and is on a budget I am sure he is willing to try some things before just throwing in the towel in my .02.
Click to expand...

He's done the tune up process, trying to use a GPS to show results. He's a fairly sharp guy, adn was able top get a couple MPH gain out of tune up changes, going from 35 to 38 deg, and doing a little jetting. He even stated he wasn't comfortable going any leaner (after looking at plugs, and rolling the motor over and looking at valves) with the GPS since it's too slow to respond to changes. He's running 101 mph right now, and says it's an improvement over his previous combo, just not happy with the fact that his "program" says it should turn 7400. He's going to try a gear change next year, but he's done for the season. Frankly, I think he's got a good running combo for what it is.

Thanks again.
 
#26 ·
Yea, the home port job raises some concern. There is some "safe" bowl clean-up porting that will help and doesn't necessarily require a flow bench. Pretty big unknown at this point with this particular motor. Is the boat a drag boat? It is pretty common for drag racers to experiment with props / gears even with professionally built and dynoed motors. Anything to get the best ET!!
 
#27 ·
No baseline info:

My most used analogy I use on customers doing the same thing - God i have a ton of them - is:

Ask Holley for a box of jets with no stampings on them. Do not look at the orifice size of the jets.

Go tuning ! :bigsmile:
 
#28 ·
The individual PM'd me from another board. He is caught in class racing. He is to fast for his old bracket and not fast enough for the bracket he would have to race in. Now knowing this I feel the combo is probly pretty good for what he has, Steel is correct, the fella is sharp and has been around drag boats for some years. To run the class competitively he needs another 6 tenths off of his time. He feels another 100 or so HP will get him there so he is going to explore his options.
 
#30 ·
Craig,
The way I understand it is you can run what you brung as long as you don't break out of the index. We talked heads and camshaft and some other stuff but he is like the rest of us and has to do what's in the budget. Heads are going to be at the top of the list though.
 
#31 ·
Well, he still doesn't know what he has now. Talking heads and camshaft for different heads doesn't help until he plunks down the money for that.

I still say pull the heads and check'm out. 1 of 2 things will happen. One will involve heads okay and need different cam or find out boat set up needs some work or 2 has to go new heads and cam.

Because of budget I'd find out what I really have and see if I can wring some more ET out of it first. :bigsmile:
 
#32 ·
Scott,
This engine has a few years on it and has evolved to what it is. He wants to run a 10 sec. class and the best he can do is mid 10's. He needs power to run 9.8's or 9.7's so he can feather the run.

I agree I would dyno the old girl and see where your at but I think his competition is all running some serious heat and this old girl in her day would hunt in the 12 second index but she is a little out classed in this lower bracket.
 
Discussion starter · #34 ·
Thanks again, guys.
I finally got a chance to talk to the guy today at length about his dilemma. Chris is right...he's stuck in limbo. He's picked up enough with his latest improvements, (which include a LOT of bottom work on a non-race hull) that he's half way between brackets. He thinks if he can literally strip the boat to bare minimums, he can get down to 10.20's, but that's just close enough to get the pants whipped off ya in the 10.0 bracket. He's talking about aluminum heads next year, more for weight savings, but I told him, bottom line is, that without flowing his heads, he's just guessing, and although he's doing pretty damn well for a small, flat tappet, single four motor, he's still probably leaving power on the table, especially where he wants it. I told him to stop, right now, don't waste any more time, money or frustration, and get the heads flowed, and then get the cam that's right. At least from there, he'll KNOW where he's going, and what to expect if he decides to change anything. He didn't sound real happy when we got off the phone. His comment was that even if the cam was wrong for the alum. heads, the weight savings would get him where he needed to be, and ther "should" be a power increase with the heads, just by their improved flow. At that point I had said all I could.

Chris, I think we raised the bar pretty high for these guys for a home built NA 467. :D

On somewhat the same note, I had a guy call me today asking about a blown 555 BB Chev. He wanted to know if his 871 that he's running on his 468 (467) would be big enough for 1K hp. on the 555. I said sure, long as you run an intercooler. He said he was. He said he was basically taking the top end off the 468, and using it on the 555. I asked what heads he had, and he said the engine builder was switching to Brodix BB2X's, adn I said, great, you'll just need to re cam, and you'll be there!
He said, "I'll need a new cam????" :eek: :(

Ay yai yai!!! :confused:

Chris...Infomaniac is building his motor, and when he asked me about him, I just told him "don't worry. He knows what he's doing". :winker:
 
#36 ·
WETTE VETTE said:
For the drag boat guy can you say 150 NOS shot! :D Cheap, easy and it will get him the power he is needing for a drag racing application.
Click to expand...
Craig that is an option also.

Steel,
I spoke with him 30 minutes or so and we disscussed his options. Should be able to get him in the right track.

Your bullet is an exceptional piece. I can't wait till you mate it to something and see how she acts when putting that power to the water.

I talked to Info the other day. He said he had some projects to work on over the winter.

Chris
 
#37 ·
steelcomp said:
OK...here's a little more info. He says he thinks it may be over propped...he's running an 11-16 with 16 gears.
Click to expand...
Casale does not make a 16% gear set.

But engine aside most v drive guys have their boats over geared. Find out what gear it really has. In that range it's 15 or 18%. Prolly would wake right up with some 12's.
 
21 - 38 of 38 Posts
About this Discussion
37 Replies
8 Participants
Last post:
cfm
Powerboat Forums at SpeedWake
posts
921K
members
19K
Since
2002
A forum community dedicated to Powerboat owners and enthusiasts. Come join the discussion about performance, modifications, classifieds, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
General Boating Discussions Powerquest News Articles