how much Horsepower?
 

Will this combo make or come close to 600 hp???
please respond


540 bowtie block tall deck
lunati crank 4.250 stroke
manley h beam rods
ross racing pistons flat top
merlin rectangular port cast iron heads
merlin single plane intake
crane hydraulic roller camshaft #hr-296 112 lobe sep 610/632
9.5 compression
comp cams roller rockers
holley 1050 dominator
msd ignition

Here is a link to a thread pertaining to 540's
http://www.offshoreonly.com/forums/s...ghlight=bowtie

Check it out

Rob

9.5 compression with flat top pistons? What is the combustion chamber volume of the heads?

caveman, I would say you'd be right in the ballpark---very close to 600hp with the parts you have listed. Are you going to do a pocket/bowl port on the heads? Have fun. :)

Bore 4.500
Stroke 4.250
head 119cc
gasket thick.038
deck height in hole .0017
valve pocket in piston intake only -.28
number of cyl 8

9.54:1

These motors are existing and running well approx 70 hrs
there are very minor porting done to the ports and some blending in the valve pockets.

never dynoed the engines and cannot get the boat to pull
past 5100 rpm at 89mph

The sad thing is this boat was featured in march 1985 powerboat magazine ( on cover) as a 103 mph Hustler 32 le

equipped as tested
630 hp eliminator 540.s @6000
1.33 to 1.00
Arnesons 1600 asd 8 with 16 inch drop boxes
spinning 17.5 x 28 4 blade rollas

Have the engines always stopped pulling at this 5,100 rpm? What is the max rpm? 6,000?

6,000 rpm would certainly put you at over 100 mph if you can get there without over trimming the drives.

If the engines are performing correctly, your primary problem here is the 17.5" diameter. Have you tried any other propellers? Smaller diameter? A new set of Mercury Lab Finished SSM#6 Propellers will get your rpms up significantly over a set of propellers that are at least 15 yrs old.

that cam could be doing it I'm not sure but I'd be very careful turning a hyd roller past 56 or57 hundred and I agree those props would be tough and another thought if the valve springs where not great when new they may be going away with those heavy rollers ,just some guesses :confused:


Also I think the comp is 9.10 not 9.54 but that quick figuring

The more I think this cam is the 741 I've used alot in 502's and its to small for your app. even on desk top dyno
I'll try and scan for you but never tried from work !!!

I just got back my props from my wheel guy he is well aware
of the rpm problem He cut back on the diamiter to 16.75
and said he added a little more rake and cup to the trailing edges
have not had oppurtunity to run yet do to horrid wet weather up here.

I have been chasing the 100mph mark on this boat for three years but never able to turn past 5100 Maybe the Big blocks are
not producing 600 hp

the 17. 5 diamiter rollas were used on the boat in 1985
with 600hp each engine and it achieved 103.

Weight was 7500 lbs in 1985
I will weigh this boat now to see where im at.
at speed the boat is stern high bow high attitude notice next picture this shot was taken at approx 75mph notice attitude.

Then when you read PB article on this hustler it had over 20 feet of wetted surface.

There is not much support lately on arneson equipped deep vees

:confused:

thanks alot for the replys I do alot of reading on this oso
and I beleave there are some knowlegable people here.

Thats why I am posting this dilema. any information or help
will gladly be appreciated.

Even at 550 hp each engine which even a sick 540 should produce
the numbers work @ 7500 lbs

The exact cam is Crane # hr-296-2s-12 ig
@.50 234int. 242exh. 112 lobe sep gross lift is .610/.632
with 1.7 comp cams roller rockers

checked plugs NGKUR4 after Speed run at 5000 rpm.
Plugs were white The dominators have 86 front 90 rear in jet size will fatten up to 90 front 94 rear and try again.
Fuel systems is as follows 2- 1/2 lines drawing from the main tank
# 8 running to fuel seperators then # 8 runs too mechanical holleys mounted on each engine. Then it is backed by Two Comp
140 gph electrics teeing with the output of the mechanicals.
Gas pressure on the Gaffrigs sits at 7psi at all speeds.

thats not where rpms are !!
its going away where it should with that cam !!
your chasing shadows until you listen to this stuff ,that cam is a common 502 cam and slighty small for it

fuel pressure is fine !!1mixture could be lean but really thats not it

I think this was the best run at 89mph notice how much lower the rooster is.

What cam would you use in this configuration?

http://cranecams.com/master/apps/chevy52.htm#3. Hydraulic Roller

this is the site where i got the info on the cam thats in it

I give up ,no roostertail no power ,it can't carry the boat no h.p.
you should have called this thread look at my boat run

AS I said I know that cam well WE'VE used alot of them it is most likly the most used cam on this board !!!!!!!

I would go to a solid roller and something in the 242/252*duration at .50 and 680 lift on a 112 lobe center then it will run also the heads need to really have a good port job ,and double check the compression it should fly

Caveman, check www.cranecams.com Crane says that cam is intended for 454-502 motors with a power range of 2500- 6000 rpms. bobbies daniels is right, that cam is too small.

THANK YOU 40 AT LEAST SOMEONE IS LISTENING !

These guys are right. Not enough cam to pull 6000 RPM. I would even go bigger than the one that Bobby recommended. Ultra Dyne has a low compression solid roller for 502-540 pleasure boat motors. The duration is 264/270 @.050 with .670" lift on a 110. That is only my opinion.

Do you have trim indicators and do they work? Do you know where the neutral trim position is?

Your rooster tail is a function of propeller rpms and trim angle, not speed.

The faster you go the lower (not shorter) the rooster tail should be.

You need to run the boat with the diameter cut down before you go messing with anything else. Otherwise you are chasing too many changes at once.

Who cut the propellers down? You should have used Hale Propellers in Ct. for this as they have experience with surface propellers.

You should be able to gain at least 500 rpm from chopping 1" diameter off the propellers. If there is no change, then you should start looking elsewhere for rpms and speed.

THis cam vette found is great for a 540 I'd go with it and I like ultadyne they make cams that are dead on !!!


Great Vette !!!!

bobby daniels, since you are on the line I was wondering if you could answer a jetting question. I bought a boat with 540's, dual 750's on a holley tunnel ram. The engines have solid lifter cams and dry pipes. At low speeds the mix is very rich. Haven't had a chance to check the plugs yet but the transom is covered with soot from one ride. (crummy Mich. weather). What do you think a baseline would be for jetting and power valves on these?

I like your combination. That combo should make pretty close to 600 horsepower. You better check the compression, it should be at least 160 in every cylinder. Is the ignition timing correct? You should have 34 degrees advance by 3500 rpm. You should be jetted fine with the stock jets (A carburetor that requires bigger jets than stock is on an engine that is overcarbed. An overcarbed engine has a low vacuum signal at the venturis requiring larger jets to maintain adequate fuel flow. A low vacuum signal can't pull as hard on the jets so they need to be bigger). Check the float levels and make sure the engine compartment is supplying enough air to the carbs. I would suggest checking the camshaft timing. While you are in there set it up without any camshaft advance. Set the intake lobe centerline at 112 degrees ATDC.
Good luck
Sincerely
Dennis Moore

I have the 741 crane cam in my 540
 

10:1 comp
Alum. Edelbrock RPM heads (ported and polished with 2.3's and 1.9's)
Straight up cam timing
Port matched Team G intake with a Barry Grant 850 flowing 930 cfm 78's & PV- 88's no PV.
HP was 683 @ 5684 and torque was 676 @ 4700
Wet CMI headers

The only thing I have done is went down in fuel 2 jet sizes all the way around.
250 hours on motor

second sheet
 

;)

Thanks for the reply Dennis, It looks like you read the topic.
We are planning another run this pm with the fatter jets
the fuel levels have been checked on the trailer. timing is locked at 32
degrees. The props have been cut back to 16.75 diamiter.
Cam timing has never been checked will check were its in at.
will check compression also. Back to the basics.

Cut and installed two scoops in the Engine hatch to aid
in the fresh air.

thanks again

Re: I have the 741 crane cam in my 540
 

Thank you for your response looks like you got quite a setup there
I see your combo pulls to 4700 rpm I think your heads and comp ratio is helping If my combo pushes 580 hp each this boat should
see close to 100

Glad to see that cam is working for you.:)

I can see your getting Frustated I can only Imagine some of the people you must deal with. I am just Trying to figure out if these
motors are producing 600 hp. I have read many of your posts
and people respect your opions I am sure youve earned it.
If the cam is not big enough and the power is being made to
low of a rpm where i need the power higher up on the rpm.
then Changing the cam is the answer It will be done. I guess
I am just trying the basics first before i start Pulling out cams.

Thanks Again For your Help.

PS. If We change the cam is there a Cam that I can put in
that will satisfy the application and take care of future Mods.
Such as a 10-71 Supercharger??? You cant stop at 100 :)

Let us know how it turns out. From where you are now your rig is going to need another 300 or so HP to gain 14 MPH. I personally doubt your motors are running that bad right now to be down that much. My honest opinion is that 10 MPH lie that is so common in magazine articles. Do the things Dennis Moore recommended and get everything right. I am sure there is some more there, but 14 MPH from some tuning is hard to buy. If you get there let me know. I have been chasing 100 for the past year and I am only looking for 2 or 3 MPH.:rolleyes:

Im reluctant to beleave that but your most likely
right on.....:(

Re: I have the 741 crane cam in my 540
 

Thanks caveman for seeing my post on your thread ,mike here has heads that really help him with airflow and more compression even WETVETTE saw this and we even saw on his dyno sheet ,,even with his great heads his torque starts dropping at 5 to 51 hundred so your motor would be worse
This is proof about your cam and Contary to Dennis you can't tune out this much speed unless something is very very off in the motor I doubt your guy could have done this ,,,but p.m. me if I can help :D :D

Was the test done in salt water? Are your speed in salt water? Just wondering if 10 mph can be seen with satl water and finding the right combo of prop,camshaft,etc?:rolleyes: :rolleyes: :rolleyes:

Yes It was a salt Water trial.
We will try to make a pm run today with the changes
(smaller diamiter) wheels.

Boat had a full tank last trial also. Will need to add more fuel to be fair on this run. 180 gallons when full.

8lbs per gallon =1440 lbs

Heck ill try it empty
:eek:

Run it empty!!!
 

I am sure Powerboat did!!

Those boats will run 100; I believe the first powerboat test was performed at Lake Mead of all places.

If you are so concerned with this 600 hp, have the engines dyno'd, if there was a lie in the article, it was that the engines probably were more only 600 hp.

Fuel is way closer to 6 lbs/gal than 8.

Be prepared for some serious chine walking at 100! The strakes are so low that they entire boat is out of the water and they all chine walk, regardless of who drives it, what power you have, or what outdrive you use.

If I read right, you have a 1985 boat. Is there any chance that your hull has developed a hook?

when we painted the boat we had it off trailer on jacks
while I was on the creeper D/A ing the bottom I checked the squareness where the trailer bunks support it and towards the
keel there were no noticeable arcs or hooks apparent.

Then again there was quite a bit of Black gel coat in my eyes.
and the fear of the V slipping off the jacks and cutting me inhalf.
:eek:

My old boat, a 26' Mirage was only a couple years older than yours. Spent all it's life on a bunk type trailer. I could check with the boat on the trailer and found a slight hook in the last foot. I used a 4' straight edge. Jacking the back of the boat off the trailer and sanding the hook out, really woke up my hull. There was a lot less wetted surface with out the hook pushing the bow down. In 4' I had about an 1/8" gap above the straight edge.

Good luck

you mentioned that you DA'd the bottom during repaint. Did you go back over with a board or block. If you just used the DA, you may have rippled the critical wetted area. For your goal, every little bit will make a difference. Also there was no mentioned as to what were water conditions on your run.

Finaly we were able to run another test run friday pm.
The test run produced 91 mph. @5300rpm
Sea conditions were calm. Slight chop

these changes were made

props cut back 1/2 inch diamiter
jet sizes increased 4 sizes
Timing at 32 degrees locked


Compression was even all cylinders 155 to 160.
High speed shut down then do a plug reading still reveals
a white plug.

A set of AFR's 335.s with a bigger cam sounds tempting.

Thanks to everyone who contributed to this thread.
Caveman

:) :)