More MPH.....

[78bahner]

I have a 78 Bahner with a semi stock 454 with a tunnel ram, 850 double pumper, r/v cam and mallory ignition. I have freshly rebuilt berkeley pump A impeller. I am hitting 55 mph at 4200 rpms at its best run? What can I do to squeeze more mph out of this boat without dumping tons of $$ into it? I'd like to run in the mid to high 60's:confused:

[squirt]

1st, What size Bahner is it?
2nd, At 4200 rpm that tunnel ram is not your friend.
3rd What exhaust are you running.
If the motor is healthy at all then you should be spinning 4,700- 4800 range with around 350 hp turnning a stock A imp. What is your timing set at......all these things need to be known before any real advise can be offered. I own a Bahner also, I'll help all I can with info.
Good luck, Don:cool:

[Duane HTP]

Check your PM

[GlastronGuy]

Originally posted by squirt
1st, What size Bahner is it?
2nd, At 4200 rpm that tunnel ram is not your friend.
3rd What exhaust are you running.
If the motor is healthy at all then you should be spinning 4,700- 4800 range with around 350 hp turnning a stock A imp. What is your timing set at......all these things need to be known before any real advise can be offered. I own a Bahner also, I'll help all I can with info.
Good luck, Don:cool:
Ya, something is not right. I have 7 more MPH in a tuna boat and relatively stock 455.

[78bahner]

Initial timing set at 10 degrees and im in the process of figuring out the total timing. The bahner is 18 ft and the motor is fresh ist year on it. I am running Basset water injected headers

[cheyenne tunnel]

I would change the impeller,or at least cut the A down to a B

[78bahner]

why is that?

[Jordy]

Originally posted by 78bahner
why is that?
Smaller impeller = more rpm's = the range where the engine makes the most power utilizing the tunnel ram.

[squirt]

Originally posted by 78bahner
Initial timing set at 10 degrees and im in the process of figuring out the total timing. The bahner is 18 ft and the motor is fresh ist year on it. I am running Basset water injected headers
I have an 18' Bahner with an almost stock 454 also (just headers and intake) 330 hp hardin so I'm thinking very simlar to yours. I ran at 4700rpm on a stock A imp. at 68 mph without the Jetovator. With a jetovator and 4deg of up wedge the boat ran best of 71.6mph on gps and would do a normal 70 most days.
I'd check your dist to see how much advance is built in, Check to see if your getting WOT on the carb (this happens). Look at your pump to see if you can spot any signs of rubbing or uncouple it and see if it spins freely. Alot of guy like tunnel rams I'm just not a big fan of them especially at the lower rpms you are turnning. Are you getting enough fuel pressure? This is where I'd start!
As for the speed how does the boat ride? is it nose down? Where does the water break on the sides? Is the bottom streight?
lets get that Bahner rockin!
get to it..........Don:D

[78bahner]

I think it all might lie in the timing? I have been messing with that distributor, weights and springs trying to find the right combo. I opted for a MSD ignition with rev limit etc, but just redid the interior so i held off on it. the most rpms I have squeezed out of this motor was 5000 on a wore out pump. I rebuilt the pump and messed with the timing and got 4500... but since installing the bassett tee valve it dropped the R's to 4200 which I have valves on the headers and will be closing them to solve that problem. I think it all lies in the distributor and total timing. I have a electric holley fuel pump that is pumping a constant 6psi at WOT and I am getting WOT. I have a jetovator already installed and am ready get this thing movin. I havent had a chance to see how it rides (wet or dry) but judging from the nose being pointed up its seems to be good water breaks off the sides a little less tha midway in the boat?

[HavasuDreamin']

If you are running a single tunnel ram, your best bet is to ditch it like Squirt said and get a high rise manifold (non tunnel ram).

[78bahner]

Yah but with a few mods like a cam and ignition wont the tunnel do me good? Id hate to take it off if im gonna do those improvements to the motor and then have to put it back on?

[HavasuDreamin']

You never see single tunnel rams on any kind real performance engine............... dual tunnel rams yes, single no. If your going for looks and aren't too much into the performance, I believe a single tunnel ram can perform decently. Once you get to a certain point with the cam, heads, etc. a victor jr. or victor type intake is the way to go with a single four set up.
My $.02

[squirt]

Originally posted by HavasuDreamin'
You never see single tunnel rams on any kind real performance engine............... dual tunnel rams yes, single no. If your going for looks and aren't too much into the performance, I believe a single tunnel ram can perform decently. Once you get to a certain point with the cam, heads, etc. a victor jr. or victor type intake is the way to go with a single four set up.
My $.02
Humm a victor Jr. HuH
http://www.hotboatpics.com/pics/data/500/3664gauge2-med.JPG
:p
Don:cool:

[78bahner]

I see, but do you think that the tunnel ram is where my problems are at? A Vic Jr might be a little better performance wise but by that much? I dunno just curious what everyone thinks I should do judging by what im running.

[squirt]

Originally posted by 78bahner
I see, but do you think that the tunnel ram is where my problems are at? A Vic Jr might be a little better performance wise but by that much? I dunno just curious what everyone thinks I should do judging by what im running.
Yes but only partly. Like I said you should be turnning more rpm with your motor. I don't know your cam specs but I was turning higher with a stock cam. I would think your tach is pretty close judging by your speed numbers (4200rpm @55 mph) so I would go over the list of things that would hold you back. If your getting WOT than check your timming total advance. Like Chris said up top something ain't right
Don :cool:

[454h20]

Go with the Victor Jr.
the single tunnel ram is weak bro...

[BigBoyToys]

Oh, I don't know about the single TR stuff. Everyone says that they don't perform well but I ran consistent 75 mph with a single 830 on a Tunnel Ram with a stock berkeley 12JI pump, "A" Impeller. I think that it's all in the setup:cool: And that 75 mph was consistent in the 1/4 mile through the lights at NJBA races....not GPS or Radar

[78bahner]

What RPM's should I be turning with the setup I have...I was figuring around 5000? Im gonna look into the timing and maybe yank the cam?

[BrendellaJet]

Get your tune up right before you start cutting that impeller. Id bump it up so 14* std and see how it responds. Make sure your carb is adjusted and go run it hard. Get out of it quick and check your plugs. There is a chart where you can look at the coloring and compare yours to it-should give you a good idea of how the motor is running. Personally Id lose the tunnelram. Ill sell you a torker for cheap if you want to give it a try, it will probably give you better throttle response and mroe rpm too. I dont think you've got enough motor to benefit from the TR. Sounds like your ignition is up to snuff, but make sure you have a good gap, and a fresh cap and rotor... You should be able to get 4800 rpm out of that thing.

[78bahner]

Yah I think my ignition is the problem? I could try and bump the timing up a little but the plugs look perfect now. Total timing is what is killing me I think? What should the total timing on that motor be 32-34 degrees?

[BrendellaJet]

that sounds like a good range, but you will have to try it out . With 10* initial, your probably getting somewhere in the neighborhood of 28-30* total-not enough. Try more, see how it runs, check the plugs.

[Cas]

my $.02
kind of forget your initial and set your total at 34º to 35º so it comes in completely by about 2800 rpms.
I'd also swap out the single carbed TR but I'm gonna go against the norm a bit. I'd go with an Edelbrock Air Gap. I gained about 300 rpms switching to that from a torker on about a 375 hp engine.
The other thing is, you mentioned an "rv cam". Most rv cams have a good sized torque curve but it peaks around 3500 rpms and the hp isn't real optimum either. I'd suggest really looking into exactly what you have so you can find out some real numbers. If it turns out the numbers are what is expected for an rv cam, you will be better served to put in something more for a jet boat.

[HotRod Sprint]

I would seriously consider losing the TR, and go with an Edlebrock Performer RPM. The air gap will probably not do anything on a boat because the air gap is designed to keep the runners cooler under the hood of a car. You would probably not see a half a mile an hour difference in the Air gap and standard Performer RPM. Also as others have said, throw initial out the window, set total to 32 to 34 and you may even want to go up a little from that.
Rod

[78bahner]

Thanks for the info I will try losing the tunnel and set the initial timing to 34. I think i'll start with the timing and go from there? wish me luck

[Cas]

what heads are you running? If you don't know, pull a valve cover and post the number, last 3 digits will be fine.
When and where are you going out next? Berryessa today or tomorrow maybe?

[squirt]

Originally posted by 78bahner
Thanks for the info I will set the initial timing to 34. I think i'll start with the timing and go from there? wish me luck
:eek: :eek: :eek: :eek: :eek: Do Not set the inital to 34 deg!!!!!
That would be a good TOTAL number!!!!!!! If this is a typo then forget this post. If it's not a typo I think you need to seek some help setting up your boat so you don't hurt it. A bunch of us here in nor cal would be willing and able to help you if needed.
Good luck Don

[78bahner]

:D Yah stupid me that was a typo I mean set the TOTAL timing at 34 degrees. Yah I was gonna go to the lake today but my co-pilot got sick so I will prolly go tomorrow, I need to get a timing light that will show me total timing

[Cas]

I'm heading to Berryessa in a couple of hours, we'll be spending the night at Steele Park. I'll bring my timing light just in case we meet up. I have a 84 Bahner 18' open bow, black with red, orange and yellow. It'll be the only one out there like it so you probably won't miss us.
btw, if you want to read about what's going on as far as local get togethers go, check here LBBA Nor Cal Get Togethers (http://p210.ezboard.com/bclassic***boats)
no need to be a member to join us

[78bahner]

Sorry i didnt make it out to the lake this weekend, but I appreciate you bringing the timing light. I am trying to get a hold of on, I have one just not with the total timing on it. I dunno much about the heads as for numbers I do know were just redone and are off a 427, they do say Hi-Perf on them but I know that doesnt mean much. I have 3/8 pushrods, guide plates and some comp cam valve springs. Im still convinced its in the timing but the tunnel could be part of the problem

[Cas]

no biggie about not making it to Berryessa, it got pretty windy today around 1ish.
One other little piece of advice, do 1 thing at a time and record your results. Doing so will allow you to see what works and what doesn't. Having the ignition as your starting point is a good idea.

[QuickJet]

Originally posted by 78bahner
Sorry i didnt make it out to the lake this weekend, but I appreciate you bringing the timing light. I am trying to get a hold of on, I have one just not with the total timing on it. I dunno much about the heads as for numbers I do know were just redone and are off a 427, they do say Hi-Perf on them but I know that doesnt mean much. I have 3/8 pushrods, guide plates and some comp cam valve springs. Im still convinced its in the timing but the tunnel could be part of the problem
If they say "Hi Perf" more than likely you have a set of square ports. RV cam plus square port heads = no power or MPH. Both are designed for two completely different RPM ranges. Find out what impeller you have then change it to a C. Either go dual carb T-Ram or a good single plane with a 2 inch spacer. On my drag cars with sqaure ports I've found that they like the timing to be in the 38-40 range. I'll be out @ Putah Creek this Sat in my Black and gold/yellow Bahner with my timing light and 2 Holley jet kits.

[78bahner]

I just checked the timing 8* initial and 34 total at 3000rpm. I had the initial set at 10 it must have moved.

[78bahner]

Set the initial timing to 10* and total at 35* we'll try that I guess. The heads say Hi-Perf, numbers 4092359 I think they are round port

[squirt]

There listed as 366 tall deck and 427 tall deck. Open chamber, oval port

[78bahner]

So pretty much they are junk??

[QuickJet]

Originally posted by 78bahner
So pretty much they are junk??
I'd look for another set if I was you. If it's not in the cards right now tune what you have. If you go to Berryessa this weekend look for us out at Putah.

[78bahner]

Yah i need a new set, I have another pair of oval port that need TLC but they have bigger valves than these. I think i'll just wait and get what I got going good before I swap heads out. I'll more than likley be there this weekend, but Im usually around markley cove...smoother water and less police there! Where is putah creek resort I cant think of where thats at?

[QuickJet]

Originally posted by 78bahner
Yah i need a new set, I have another pair of oval port that need TLC but they have bigger valves than these. I think i'll just wait and get what I got going good before I swap heads out. I'll more than likley be there this weekend, but Im usually around markley cove...smoother water and less police there! Where is putah creek resort I cant think of where thats at?
I usually launch at Markley but since I started running 100 octane @ 4.29 a gallon I found it more economical to launch @ Putah Creek since that's where I always end up anyways.
Putah Creek is twords the upper west side of the lake. As you head north past the open water it's the 1st bridge you see on the left past Spanish Flat. Durring a busy weekend it can be hell getting there with all the rough water.
What color is your boat?

[78bahner]

Oh ok your talking about the "Bridge" where everyone partys? Yah I go there all the time but usually it beats the shit outta my boat and all the passegers, thats why I usually stick to markley. My boat is mainly white with some blue and yellow trim.

[QuickJet]

I'll keep an eye out for yah.

[Taylorman]

Maybe a tunnel ram is not the best option for your rpm range but i would not get rid of it. I had a single tunnel ram running at 4600 rpms. Sold the single top and 750 carb and bought a dual top and two 600 carbs. That gave me 250 more rpm's and it runs so much smoother. If you like the tunnel ram, id do that. Best change i ever made to my boat. I surely would not cut my impeller down. Your not running enough hp to run a B impeller.

[Cas]

another thing about the tunnel ram, I don't think there is one made for the small oval port heads. More than likely you have a TR for rectangular port heads or possibly the large oval ports. In any case, neither of them are going to match up to your heads.
I could be wrong though.

[78bahner]

Yah you might be right, Im gonna replace the heads, cam and intake after this season. I already replaced the interior and am having the thing painted...costly, So i am going for the cheap mods or obvious problems i might have.