Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   540 n/a help (little long) (https://www.offshoreonly.com/forums/general-q/54802-540-n-help-little-long.html)

carreraboat 07-18-2003 04:12 PM

540 n/a help (little long)
 
here is the breakdown 540 with 6.385 rods 10.25 compression with canfeild,s 315cc runners, roller cam, lightning headers,ok i wanna make 800 hp is it possiable n/a? my questions are
(1) i have a dart intake and a rpm performer air gap that are 4150 base with a nickerson preped 980 cfm holley do i stay with that or go dominator?
(2) what cam? i have a simular cam to the 741 but is big enough it is a roller if not which one? i have wet exhaust so i think it has to be at least 112 center line
(3) do i use a vaccume pump and run low friction rings is it worth the cost?
iin advance i apprecitate your advise
i looked under numerous other threads i could not find what i was looking for? mike with the htm has a n/a motor but he gettin a little over 650hp ouuuta his is he maxed out is 800hp asking too much
thanks bo

DanB 07-18-2003 05:11 PM

Nope...not 800
Let me rephrase that....not with what you have

Dan

carreraboat 07-18-2003 09:01 PM

what would it take to get that out of a n/a set 540 kinda stuck on that part because already got all the hard parts

Back4More 07-18-2003 11:42 PM

A good start would be to pitch the nickerson carb for the 1050.
650HP would be more real world numbers

26scarab 07-19-2003 09:06 AM

For starters I would switch the carb and intake.
I'd go with a Brodix intake and 1050 carb.
I also don't think your going to accomplish 800 hp with a hydraulic roller cam. Look at the supercat motors. I believe they are 510 ci with high compression and are making in the 800's.
Now my N/A 540 (9:1)is making around 675hp and with the current solid roller I have it is brutal on lifters. With the help of Bobby Daniels hopefully I will be getting another cam that is going to be more reliable.
A friend of mines 565's with 8.25:1cr made 720 on the dyno. He's got D-ports , the carb and intake I mentioned and a big solid roller.
I think 700-750 is reachable, but not with some of the parts you have.
Even with a 112 c/l , if you go with a sizable cam you will recieve reversion. My first try with my N/A 502 (8.5:1cr 625hp) with a cam that had some duration numbers of 258/264 @050 with tailpipes that had the water entering 18" from the elbows still had reversion. I had to switch to dry CMI's
Now I'm no pro engine builder, these are things I've learned the past few years since building this 540.

carreraboat 07-19-2003 01:02 PM

so do you think 10.25 is too high of compresion

carreraboat 07-19-2003 01:13 PM

so scarab should i use a solid roller dont mind if that is the way to go what did bobby daniels do for you the cam dept to make up for the reliablebility issues

Tinkerer 07-19-2003 09:47 PM

Jim V. is getting 750 Dynoed HP out of his 540. He is running 10.5 to 1 compression to get that.
In order to get 800 HP out of your 540 you would have to run about 12 to 1 compression and other parts. Jim is running a tunnel ram intake.

26scarab 07-19-2003 10:59 PM

Good question on the solid roller thing. Lashing valves is not too big of a deal. expecially if you have Jesel rocker arms, they make things easier. Now the reliablity issue is yet to be decided. All my friends have solid rollers in thier boats and have had better luck than I. If you go that way make sure it is a cam with low ramp speeds . It will be easier on the valvetrain.
I really don't think you need to go over 10:1.
Your going to need just the right combo of cylinder heads, cam to make the power. Although the closer you get to 800 the less reliable it is going to be.

PatriYacht 07-21-2003 09:20 AM

Popular Hot Rodding magazine had an article about a Bill Mitchell n/a 800hp engine. Here's a partial parts list...

705 ci. Merlin block
Brodix-5 cylinder heads, sportsman porting
410cc intake ports.
.705 lift solid roller cams (duration not listed)
Hogan sheet metal tunnel ram with 2 1050 Dominators.

This engine made 778hp at 5000rpm. Using similar components a 540 would have to turn about 7000rpm to make the same hp. The valvetrain would be the limiting factor. Boats are not drag cars. They have to run for more than 10 seconds at a time You would be changing valvesprings and lifters twice a short Mich. season. Why not use a blower ?


All times are GMT -5. The time now is 02:49 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.