Author Topic: cvx-18 exhaust (Read 65447 times)

Shrom CVX-18 · « **Reply #100 on:** April 02, 2011, 08:35:50 AM »

Quote from: wexrocks on April 01, 2011, 10:10:11 PM

poor Shrom, we keep finding different agendas to step all over his thread with! ahh, such is life on forums I suppose. sorry Shrom! we'll talk about your boat, I promise!

just playin'... I'll get ahold of ya tomorrow and see how it's goin.

Thats ok guys lol.

I was actually going to get on the subject of props anyway. I ran a 19 pitch last year and topped out at 55mph with ideal rpms. I was wondering if anyone knew what I could probably get away with now with my new additions to the engine? I have a 21 3blade to try and a composite 22 4 blade. but I because it is composite and 4 blade i don't think it will give me full advantage.

GT150 JEFF · « **Reply #101 on:** April 02, 2011, 09:00:44 AM »

Craig

Running a stock mercrusier 260 would run out at 59.6 with a 23pitch Mirage at4600rpm

After mods to my engine new RHS vortec heads,cam and intake approx 350hp with a 23 mirage 61 mph at 4600rpm
23 laser II 67 mph at 5000rpm

Going to try a 25 laser II this spring hoping to bring my rpm down and speed up a couple mph

So it takes a lot of hp to make em go fast, by adding 100hp only gained 8mph on the same pitch prop but gain a little in rpm.

Torque plays a big roll in getting them to move, the cam I used is a high torque (kind of like a RVcam) but kept it mild for idle purposes.

I know I rambeled alot but hope this helps in your prop selection.

wexrocks · « **Reply #102 on:** April 02, 2011, 09:42:59 AM »

I definately believe prop pitch and brand have alot to do with it. The California edition CVX18's were running low 60's off the showroom floor with 260hp. Like GT-150 Jeff said, he gained 5mph with the same pitch, just different brand. I have a 21p bravo you can throw on there for a run also if you want to try it.

CVX Fever · « **Reply #103 on:** April 02, 2011, 09:50:45 AM »

Shrom I've ran a 21P SS Laser, 22P SS Enertia, and 23P SS Laser.

The 22P & 23P props were too much pitch for my boat and gave pretty much the same top speed(57 MPH GPS) as the 21P but were a lot a slower out of the hole. My WOT RPM's w/22 & 23P props were 4000- 4100 RPMS lightly loaded. Too low. The 21P put me right at 4300-4400 RPM.

I would start with a 21P and 23P SS 3 blade prop. The Lasers seem to work pretty good on these boats. You definitely want a prop that will give you some bow lift.

Shrom CVX-18 · « **Reply #104 on:** April 02, 2011, 06:20:25 PM »

Thanks guys. That helps me out, I have heard that the Laser props was a good choice. I will have to do some testing before I break down and buy a new prop. Wex that would be great if I could use that prop to test out.

I was able to get my boat in the garage. I got the engine aligned and outdrive on!! Boat looks so much more complete.

I think before I take it out on the water I am going to put a new impeller in. Just to be safe. The new coil is on and when I went to hook up the electronic destributor kit. I realized it already had it....I felt like an idiot.

Why didn't I check that before I ordered it..Owell. So if anyone is looking to do the convertion let me know I have one for sale.

dorelse · « **Reply #105 on:** April 02, 2011, 08:53:58 PM »

I'm going to assume that the CVZ-18 can use the same props as the CVX's...

Shrom - who makes the composite prop you have? I've been extremely happy with Piranha props and do actually plan to run them on whatever boat I end up keeping. (Which looks to be both!)

Rosscoe · « **Reply #106 on:** April 03, 2011, 08:15:24 AM »

Quote from: GT150 JEFF on April 02, 2011, 09:00:44 AM

Craig

Running a stock mercrusier 260 would run out at 59.6 with a 23pitch Mirage at4600rpm

After mods to my engine new RHS vortec heads,cam and intake approx 350hp with a 23 mirage 61 mph at 4600rpm
23 laser II 67 mph at 5000rpm

What is the supposed red line on Marine 350's anyways?

Rosscoe · « **Reply #107 on:** April 03, 2011, 08:20:03 AM »

[I was able to get my boat in the garage. I got the engine aligned and outdrive on!! Boat looks so much more complete.

I think before I take it out on the water I am going to put a new impeller in. Just to be safe. The new coil is on and when I went to hook up the electronic destributor kit. I realized it already had it....I felt like an idiot.

Why didn't I check that before I ordered it..Owell. So if anyone is looking to do the convertion let me know I have one for sale.
[/quote]

I would be interested in your kit. I have to look at my funds however. I'm already over what I was going to spend this spring.
This is for a Mallory, correct? Which coil did you end up going with?

Shrom CVX-18 · « **Reply #108 on:** April 03, 2011, 09:02:26 AM »

I would be interesting in your kit. I have to look at my funds however. I'm already over what I was going to spend this spring.
This is for a Mallory, correct? Which coil did you end up going with?
[/quote]

Yes That is correct it is for a Mallory, 8cyl here are links to the exact coil and Electronic ignition I got. I read the instructions and seems to be vary simple to do. I will bee sending you a PM.

http://www.cpperformance.com/p-14217-electronic-conversion-for-most-mallory-v-8-distributors.aspx

http://www.cpperformance.com/p-14072-black-40000-volt-coil.aspx

Rosscoe · « **Reply #109 on:** April 03, 2011, 09:12:29 AM »

What worries me is that is says "fits most" and mine being so old....well, you know. Its considered a "flat top" from what I've seen.

Shrom CVX-18 · « **Reply #110 on:** April 03, 2011, 09:20:39 AM »

Quote from: Rosscoe on April 03, 2011, 09:12:29 AM

What worries me is that is says "fits most" and mine being so old....well, you know. Its considered a "flat top" from what I've seen.

I know what you mean. I agree with you on that. I kinda took a chance on it myself. Ended up not having to so anything anyway

Didn't know whether to be glad that It was done already or upset that I just spend the money on something I didn't need...Lesson learned.

wexrocks · « **Reply #111 on:** April 03, 2011, 10:36:49 AM »

Hey Shrom,
was hoping to make it over there this weekend, just didn't have time! Busy, busy. Sounds like things came together for you pretty well. I've got my carbs back on and just about ready to fire for the year, so I should be all systems go when you're ready for a river test. Gotta go take the kids fishing... guess I'll work on my stuff later!

Shrom CVX-18 · « **Reply #112 on:** April 03, 2011, 06:57:13 PM »

Wex, or anyone else. I am almost confident it is pre alpha but not 100% I looked it up for the outdrive gasket but the one I ordered worked for many diff models and it worked fine for mine.

But i don't think the impeller kits are as universal as a gasket are. Could you tell me what out drive I have? I need to know for ordering a new impeller kit. and maybe where you order your parts from. Wex do you just go to Conestoga marine for these parts?

wexrocks · « **Reply #113 on:** April 03, 2011, 08:18:57 PM »

Yup, I did, I just gave them the year and that it was the 898 combo. It is a pre alpha, but not to worry, just tell Dennis (don't bother with anyone else in there) and he'll fix you up, that guy is a walking boat encyclopedia! The kit is like most where you will have left over parts, so it is very possible that the same kit works with the alphas (I'm sure someone here knows) but they can look it up and get the right thing. I did replace the impeller and housing last year on that, but I'm like you and like to be safe. I will tell you I had a heck of a time getting it all lined up with the shift rod in the right location. Things are beginning to get a little loose and sloppy in there, must have had it off 3 or 4 times trying to get it lined up the way it originally was. I usually get it the first time, not so lucky with that one. If I remember correctly, I had to keep it trimmed down as far as possible just before I slid it the rest of the way in (and cranked the nose of the trailer all the way down). If you want to do it some evening or next weekend, I'd be glad to help, hard to wrestle that thing up in and keep it all lined up.

Shrom CVX-18 · « **Reply #114 on:** April 05, 2011, 05:28:13 PM »

Thanks Wex,

I do remember you saying that you had replaced it when you got it last year. But The way I look at it is. Sense I have done all this work to it over the winter, why not be sure and replace it. That way If I do have any over heating. I can rule that out as being the problem. I am going to pick one up this week hopefully and get it in this weekend. I'll keep you posted. I want to have it water tested before May!

Of coarse that is only if the weather permits it.

Shrom CVX-18 · « **Reply #115 on:** April 17, 2011, 05:31:57 PM »

Was able to get the hatch back on today. It's official, The Name is on the boat

Rosscoe · « **Reply #116 on:** April 17, 2011, 07:56:50 PM »

Looks sweet! All done, now what are you going to do?

Grinder · « **Reply #117 on:** April 17, 2011, 08:54:19 PM »

Have you had it out on the water yet?

wexrocks · « **Reply #118 on:** April 17, 2011, 08:56:56 PM »

Quote from: Rosscoe on April 17, 2011, 07:56:50 PM

Looks sweet! All done, now what are you going to do?

he's gonna take it out on the Susquehanna River and smoke my sorry a$$, that's what!

lookin' good Shrom! Now, if it ever stops raining and the river goes down, maybe we can get these babies out for a shakedown run.

Shrom CVX-18 · « **Reply #119 on:** April 18, 2011, 11:15:01 AM »

Quote from: Rosscoe on April 17, 2011, 07:56:50 PM

Looks sweet! All done, now what are you going to do?

thanks. It is not all done yet. But close to it. However it is ready for a test run once the weather warms up and stops raining. And like Steve said when the river stops flooding...all little stuff from now on. I think will need to adjust the carb a little seems like it is running rich. Anyone have any pointers? I did not get it out on the water yet. I have off work Friday and hoping the weather will be clear so I. An possibly test her out.