how to get a NR 5port to RPM

[anthony_marquart]

4lb clean running rigger

50% GR fuel

SPP carbon pipe at 7.5

1450, 3.3 x 46.5

head room 8-10

Just not turning the RPM I would like...

Have you guys had much luck putting the 7 port P/L in this engine? Did it make a real difference?

I also have a AB parobolic,.. do you think will turn better RPM? The spp is the old muffled kind... might it be getting soft?

I have gallon of Odonnel 65%, just picked it up as old stock, it has just a little bit of color in it.. not much though,.. still good?

 

[RodneyPierce]

how are you measuring RPM??? If its muffled, are you sure its not turning RPM, just doesnt sound as mean and loud as a non muffled version?? 7.5 on the pipe, should be screaming for mercy. You can raise the exhaust port timing, thats going to let you get more on the top end, but your going to lose some of your low end torque. Also can squeeze the head space down abit more to pick up some compression and help regain a little lost torque. BUT, YOU BETTER HAVE A WAY TO ACCURATELY MEASURE YOUR SLEEVE AND TIMING BEFORE CUTTING!!! Or, just send that little motor to Steve Wood, and not worry about it anymore.

 

[Terry Keeley]

4lb clean running rigger

50% GR fuel

SPP carbon pipe at 7.5

1450, 3.3 x 46.5

head room 8-10

Just not turning the RPM I would like...

Have you guys had much luck putting the 7 port P/L in this engine? Did it make a real difference?

I also have a AB parobolic,.. do you think will turn better RPM? The spp is the old muffled kind... might it be getting soft?

I have gallon of Odonnel 65%, just picked it up as old stock, it has just a little bit of color in it.. not much though,.. still good?

Over propped in the heat?

 

[Blackout]

Are your head temps getting hot enough? I run little to no cooling on my 5-port Novarossi.

 

[Ron Zaker Jr]

4lb clean running rigger

50% GR fuel

SPP carbon pipe at 7.5

1450, 3.3 x 46.5

head room 8-10

Just not turning the RPM I would like...

Have you guys had much luck putting the 7 port P/L in this engine? Did it make a real difference?

I also have a AB parobolic,.. do you think will turn better RPM? The spp is the old muffled kind... might it be getting soft?

I have gallon of Odonnel 65%, just picked it up as old stock, it has just a little bit of color in it.. not much though,.. still good?

I would look at your MPH first,then rpm.

 

[anthony_marquart]

Well,.. I'm say noting saying it's not fast. It's actually running better than ever.. I have run .12 riggers most of my boat life,.. and yes,.. everything sounds slow compared a modded .12 at full song!

I am going to go run with some other people early tomorrow morning. I was running alone with no radar to even have any idea what speed I'm at.

I have blocked the water outlet and drilled a 0.050 hole in the head to flow water. I think I'm up to temp.. Going to add prop tomorrow,.. I've heard that this engine is not a big RPM turner,.. has some decent torque.

One other thing guys.. it seems to come un-hooked pretty easily, The tail comes loose over waves a bit more than I would like.. .. what would be an idea to solve that,.. It's a new boat,.. running fantastic except for coming unhooked a bit... No hppping at all!!!!!!!

Would a bit of negative on the prop make that wave hop worse?

 

[Glenn Quarles]

Tony, the ideas posted above are all good. First, the speed will tell if you are turning good RPM because the sound of a muffled pipe makes it hard to tell sometimes. Second, the temp is VERY important...the size of the hole in the water jacket doesn't mean you are getting up to temp...after a run it should be hot enough that you can hold your fingers on the head for only 2 or 3 seconds. If you can keep your fingers on it longer that that it is too cool.

Another thing is what you are comparing it to as you determine it is not turning enough RPM? I have a stock 5 port that turns (what I consider) very good RPM...not the kind of RPM my 190 degree SAW motor turns in my 2 lb boat, but that is not what I am comparing it to. Again, I think the speed and maybe the sound of another pipe will give you a better idea of what you are actually getting. If the motor is pulling your prop OK try a shorter pipe.

I think you may be better off than you think you are right now. When you get around other .21 boats you will get a better idea of how yours is doing and if you need to be looking for improvements.

Glenn

 

[SayMikey]

I dont think you will pull a full size 1450 and get big rpm. Id start with a smaller prop and get all I can out of it then add more prop. h-7 or 1445 make sure they are sharp as a razor,when you get your motor,pipe and prop right the 5 port will sing just fine...

 

[tmunn]

For what it's worth I have a jae with 5 port and it does not sound peaky and sharp as others i have seen but it has a 3280 with the brass mod in the stinger like terry keeley told me about and it runs real well and pulls a 1450 that i just B&S myself no idea on prop numbers but it wins heats.

I will be trying a 7 port in a few weeks when i get to it.

 

[Tim_Duggan]

Are you running a 3rd channel for mixture? Some of the early SPP's like a rich launch, but once they get some heat on them they can be leaned down quite a lot and they really come on strong. Launching at the final needle setting results in a stalled launch, so it's safer to go back to the rich setting for the launch and lean down again.

As for the prop blow-out, how much weight at the strut? you could be a bit too light at the strut.

 

[Mike Larson]

Anthony... pull the pipe out an 1/8th till it hits.... and it will.....i've a pair of the muffled, and have ran the TD, MS, and other bellied ones also.... they have all shown measurement to be critical on length..... your variables into account.... I always epoxied/RTV, mine to the header coupler also, as they'll oil up and slip....... made for a little twinge if you were short for a test session with it locked down........ Tim's words ring true as sometimes just finding the launch needle, to click it down during a mill pass makes things interesting...... they love the heat and almost seemingly feed on it..... it should be crack and popping when you finish a test...... Hummingbird rigger, Bulifant worked engine, SPP muffled, Byron's 45/16, ABC 50X69 @ 3.4 reduced to 46..... high passes @ 72. Keep at it and hang on when it hits.... Mike

 

[moparbarn]

anthony, .050" cooling outlet sounds a little too large to me. all of my .21's seem to end up liking .030" to .035" for good heat.

 

[anthony_marquart]

I got some good testing in today,.. I found a decent set up and ran solid 66mph laps. Jim Allen was a huge help,.. I need to change a few things and get back at some testing.. The engine was plenty hot..

 

[Terry Keeley]

I got some good testing in today,.. I found a decent set up and ran solid 66mph laps. Jim Allen was a huge help,.. I need to change a few things and get back at some testing.. The engine was plenty hot..

Don't beleive all the "keyboard" speeds out there, if you are running 66 mph and have a good handling, throttleable setup you'll be able to win anywhere.

 

[SayMikey]

I got some good testing in today,.. I found a decent set up and ran solid 66mph laps. Jim Allen was a huge help,.. I need to change a few things and get back at some testing.. The engine was plenty hot..

Don't beleive all the "keyboard" speeds out there, if you are running 66 mph and have a good handling, throttleable setup you'll be able to win anywhere.

 

[RodneyPierce]

Don't beleive all the "keyboard" speeds out there, if you are running 66 mph and have a good handling, throttleable setup you'll be able to win anywhere.

This is awesome!! And oh so truthful!!

 

[Ted buckley]

Don't beleive all the "keyboard" speeds out there, if you are running 66 mph and have a good handling, throttleable setup you'll be able to win anywhere.

This is awesome!! And oh so truthful!!

Don't see any reason to flip to a 7 port with speeds like that :huh: :huh:

 

[dwilfong]

If you have good throttle and can run 66 put it away till race time.

David

 

[Glenn Quarles]

Tony, you are good to go with 66mph laps...no changes necessary!

Great job.

GQ

 

[moparbarn]

anthony, glad you & jim got together to run, he's a super nice man & very knowledgeable. did you run at their club pond? any chance that you'll make it up to the last d-12 race in centreville, va. at the end of august?