Cylinder wash down is common on the 575 with stock mapping...after running mine with a custom map I would NEVER go back! For anyone with even a stock 575 it is recommended.

I'd like to see the dyno proof of that! Stock flat tappet cam, heads, 7.5 cr and programming? :bsflag:

I been running NGK 5673-8 in my engines for years. Mine are supercharged, and carbureted. I do not have plug fouling issues, but, I do have Crane CD ignition boxes, good plug wires, and coil. So that may help.

As far as "heat" generated by blowers, yes, it is true the harder you spin them, the more heat they make. However, if you take a 8-71 and turn it say 1:1, then change pulleys and go 6% over, you wont likely see a huge change in manifold temps.

Icdedppl installed air intake temp gauges under his non intercooled 10-71's, spinning at 3% underdriven. While watching his air temp gauge at 5000+RPM, never saw it go higher than 130*. I'd say on that particular run, we were about 5000RPM for 30 seconds or so doing some carb tuning on the river. Actually the manifold temps were hotter at idle and slow speed, around 140ish. I am not sure how much an intercooler would help on his setup that day. Water temp in the river was probably around 80* and outside air temp was around 83*. It be great if the intercooler could get the intake temp down to ambient, or whatever the lake temp is, but i dont believe the typical superchiller style core is that efficient. or is it?

I personally would love to see some data on manifolds temperatures, on these style blowers, with intercoolers. You would think with Teague, Blower shop, the old LEE intercoolers, someone would have been able to provide some data on temperature change before and after the installation of their product. And not just talking about a quick pull on the dyno. I'd like to see the temps after a long hard run when the outside of the core gets some heat put to it.

Ugh.......Where do you find your "knowledge" ???

So the 256 not much more than an N/A motor huh, you claim you are making 700 HP (you're not BTW), andyou think that power is coming from your 7:5-1 502 iron head engine with a flat tappet cam that is slightly more aggressive than a lawnmower? Take the supercharger off a stock 575sci and you will make about 400 hp, if that.

A larger blower brings in more CFM, therefore you can run lower boost with a larger blower to make the same power as a smaller blower with more boost. Boost is compressed air, more air. Compressing air causes heat, the more it is compressed the hotter it will get. So yes a 8/71 blower will make more power at 3 psi than a 256 at 5 psi, plus the charge will be cooler because the 871 is feeding more CFM. A 256 blower makes 256 cfm per rev, a 6/71 is about 400, and an 8/71 is about 445. if you spin a 256 at twice the rpm of the 8/71 it will make the same or close to the same power. The charge on the 8/71 will however remain cooler, which is worth a few ponies

The 8/71 conversion from dyer is a great set up for a 575sci. I can see that set up making 800 hp with a cam and a little more boost. However, how much can the lower end and a bravo drive handle?

You seem to be butt hurt about something, and I am not sure what it is. Kinda fun to watch.

Any more bad advice you want to throw out there?

I agree 100 percent. Funny how that testing data doesn't exist, it could be damning to the sales of chiller if a significant improvement wasn't shown. I would really like to see a speed, rpm comparison before and after chillers. I have access to 2 super chillers, I haven't convinced myself they are worth the effort to install to see.

I know chillers work at idle! My old boat with a sea pump chiller set up used to get so cold in the spring and fall idiling it would pool the fuel and kill my engines, I used to bypass them in all but the hot summer months :D

Okay, Spark Plug 'heat' range is all about transfering heat to the cylinder head.

It's very simple: A hotter plug retains more heat and a cooler plug transfers heat faster to the head.

Combustion chamber heat is what the spark plug sees.

Air temp somewhat contributes to it, but not a bunch unless it gets high enough it causes detonation and such.

More air and more fuel per event causes more BTU's. So, this is a huge factor to spark plug heat range chosen.

RPM is also a factor. More rpm = less time the plug has to transfer it's heat to the cylinder head.

A cylinder head that transfers heat faster to the cooling system will also effect plug heat range> Not a bunch, but some.

All spark plugs must reach a certain actual F* temp or they will foul easily/quickly.

All spark plugs when reaching a certain actual temp will start to turn red hot and thus become an ignition source without spark. That causes pre-ignition and eats motors obviously.

So.....how do we get a plug that runs near hot enough at idle (low rpm/not much BTU's/lot's of time between combustion event to cool off, etc,etc) but doesn't glow hot at high rpms and load ?

Tough.

But, if you have to chose one issue, you choose the colder plug that may foul.

And if you do have to chose this way, meaning foul more often then you want, this is the real reason for big powerful multi strike ignition systems.

Food for thought.

BTW: You can read the ground strap to see if you have the right temp plugs.

Here is one article: http://www.dragstuff.com/techarticle...ead-plugs.html

From NGK: http://www.ngksparkplugs.com/tech_su...k_plugs/p2.asp

I love my Dyers setup........

I would love to see it myself! But is was done aprox 8 years ago and he said it's hard to pull up that data from a boat that was done about three owners ago!

Check out this


http://teaguecustommarine.com/em0011...-kit-2391.html

How much speed did you gain again on your 40 outlaw when switching the blowers out to the 8-71's???

I am going to stop reading your hatefull posts. If you have a problem with the way I learn , it is your problem. Not mine. If you add 125 hp to a 525-540 hp motor you have about 650 or so per side. That is what I have always claimed. If I had 700 hp I would be at about 104 mph . Where you should be

Hmm. As much as I repect Teague I question an additional 50 hp by changing the fuel pump to an Aeromotive, that is a bold claim! The 575 never had a fuel delivery problem stock, in fact it has always had too much fuel :D Maybe the claim comes from turning the regulator down from stock vs programming the BPW in the ECU (the proper way).

Where is the 678- 700 claim coming from? I would assume the 3.25, 3 inch pulley, and adding fuel volume with the aero stuff to feed that boost?

3.5 = 650
3.25 = 678
3 = 700

What pulley do you have?

The 575sci is 550 at the prop, 575 at the crank....stock.

I don't have a prop shaft dyno, most don't......so most aftermarket mods are referred to as crank shaft power so the world can relate, without doing the merc math.

The way you learn is to put out bad advice? You started up my shorts, questioning my set up, recommending plugs 4 full heat ranges hotter to the OP, and making out-landish claims and comparing my boat to yours (there is no comparison, we have different bottoms)

Why should I be at 104 mph? I could be at 110 mph if I wanted. I want a boat that works every day, and is rare to break. Sure there is speed to be found with short lowers, 5-6 blade props, bottom work, things to lower my slip and put even more stress to my XR drives that are already being fed too much HP.

I'll take my 98 mph every day, and 101 mph on the 5850 limiters when the conditions are right. 15 percent slip is not the best, but drives are in the water, and 15 takes a little bit of the stress away.

There is one thing I agree, you are making HP if you are running he speed you claim, and turning the RPMs you claim with a side by side small step lightning. Where your HP came from will remain a mystery I guess? Because an MSD box, with 3.5 pulley and chiller won't get you turning 5800 rpm at 100 mph in a 38.

What props are you spinning to 5800 ?

I agree, after the first 60 hrs on my engines from new, the builder described what he saw as "dangerous piston wash" I was getting AFRs under boost stock tune that would dip into the 9s! This was after the cam change, and increased boost!

SB !!!!!!! you are a Gentleman and a scolar!~! I thank you so much. The stock plug heat range too cold I am pretty sure See pic. And maybe I have some of the problem Rob described going on? This motor uses less fuel than my other one i beleive though

Cooerlman, Jason and his dad have a lot time with blowers and coolers plus sell a cooler.- of course they are at Lotto doing the shootout and the rest of us are stuck up here. I know for a fact they have done a lot of tuning on the dyno plus have a lot info from their testing. Maybe he will chime in after his vacation. Had to bust on Jason, he is a cool dude, no pun intended coolerman.

I'll give them a little plug again no pun intended.

www.pfintercoolers.com

I picked up a solid 8MPH...hit 81 a few times but 77-78 even this time of year. I'm actually getting ready to take her out and some data logging with MEFI Burn.

Do yourself a favor and start by zeroing out the bpw vs ect cold start (choke). It is not needed and give terrible readings until the engine reaches 140 degrees. I don't know who at merc thought the engine needed to be at 8 afr until it was warmed up. I fiddled for a while then just took it out, even on the coldest of spring days I still have readings on the rich side at start up, but now I can actually move the sticks from dead cold and rev them up clean.

Good luck with your tune. I tuned mine to 11-11.4 full boost. 12.5 cruise, and 12.5-13 idle. Some say go leaner, but I am happy with that set up. Clean but on the safe side.

If you are seeing a big difference in readings from one engine to the next take a close look at map senson, and ect sensor (different than the gauge on dash) also you can peak at the injector spray patter with the spark arrestor off. Use timing light triggered off cyl 1 and point it at the spray for a clear reading.

Here's a thought. Start by leaving temps out of the equation.

Boost is a result of backpressure from pistons, valves, etc.
5PSI is 5PSI is 5PSI
Doesn't matter if it's a 256, 14:71, turbo or hair dryer.
A 575 w/256 @ 4PSI @ 5K RPM makes X HP and a 575 w/8:71 @ 4PSI @ 5K RPM makes the same X HP
A 256 makes more heat so you may loose power. On the other hand, spinning more mass(8:71) takes more power. It's probably a wash at these boost and RPM levels.

I would think that the 256 would create better low end power but run out at the top, or at least become less efficient because of heat, not to mention the bearing issues. Whereas the 8:71 would have a harder time building boost at lower RPM's because of leakage but could keep up with the demand of higher RPMS, all the while creating less heat, but demanding more HP to turn.

Now, we're at say 4500RPM and goose it to 5K. I'd think the 8:71 would be more responsive to that demand(by milliseconds) than the 256 but ultimately they would end up at the same HP at 5K RPM.

If you could keep the air temp down and bearings alive, put a 1" pulley on front of the 256 and it'd keep up with the 8:71

Then we go to Whipples. I think they can create the same boost as any Roots style blower without the low RPM pressure loss, hence more bottom end, and take less HP to turn because of their smaller mass.

Enter the world of turbo's. Same deal as small Roots to larger roots without the parasitic HP loss, just backpressure issues to deal with.

Don't mind me, just thinking out loud, rambling....and bored.

Have a great weekend, I'm gonna go clean my plugs.
Rob

Use timing light triggered off cyl 1 and point it at the spray for a clear reading.[/QUOTE]

Cool idea!

Stock 575 sci motors with yR5's for Years and no burn on the pistons plugs or anything,. How is this possible. That is the question. Maybe the blower shop makes just that much better 250 blowers. I am at about 6-7 psi boost. I would really love to know .

I'm actually confused as in this thread you say they have been running great, but in This One Here you state one had a hole in the piston.

Gear ratio 1.5 prop 32 p rpm 5600 speed 98.0. I know I say 100 and it will go 100. Just not where I tested. I tested at 1300 feet of elevation on a flat calm lake . SO I "assume" it will go 100 in the right conditions , plus I have a new motor (it always ran kinda weird before). My star motor was carrying the old motor a bit. You can tell when you accelerate. So maybe even 102 when it's all said and done. But I am confident of 100 @ 5700 rpms give or take. I never told anyone what to run in their motor.

Well this is off topic, but If you run your boat hard testing props all day, be careful backing the boat back in the water.Cold water can go in the exhaust pipe and get into the cyl. The heads are hot and some cold water splashed in the exhaust and shrunk the valve seat enough to dislodge it. It has to be a perfect storm. The motor has to be hot. The water has to be cold and the valve has to be open so the seat can fall out. Happens with alimun heads and cast iron heads. And It happend to me. Just sucks, but i will deal with it. Also bad exhaust manifold gaskets can cause water to get in there too. It happens to bone stock marine engine now and then . ask anyone. The solution.. Change the friggin props out while the boat is in the water.

Well your 32 bravos are actually 31.5 (or less) and that makes for 11-12% slip...........must be doing something right.

thank you! And they are not Bravos though, they are Herings ;)

So you are saying the compressed air that comes out of the blower shop blower is of higher quality than the stock 575 blower? lol

The BS blower is still a roots style 250 blower, which means it makes the same cfm as the stock blower. Where it is different is the fact that it is beefier construction, so less prone to failure. It is a nice upgrade for strength, but it ends there. In fact, being that it is billet construction, and heavy duty, it may actually retain more heat.

If the plug is working for you, who cares I guess. But you didn't build your set up, so we may not know all the details of what was done. We also do not know your driving habits. 2 weeks ago I did a 125 mile poker run and never went below 4500 rpm, and was WOT half the run. That is why I was harping on you for making such a bold statement about what plug the OP should run.

Are you running the stock E-tops with the split routing that Fountain runs factory? My tails split half to the bull horn bottom exit, and half to the thru hull.

4 bus, I am pretty sure my set up is all stock as Sanborn and the guys set it up in 2005.I have nothing to compare it to to be sure. I know the engines are stock cause i just had one apart.. The chillers are part of my water exit. I don't think I will ever go by what you say. Uahua ha ha ha

Is there any legitimate reason for having R5673-9 plugs in a stock 575? Engines have been fully rebuilt, I'm told to stock specs, but they do make 590 hp at crank. I have terrible soot in spring and fall. While I have the greatest of confidence in anything Eddie recommends, I'm nervous about dropping all the way to 7's because I don't know what I don't know. I'm thinking maybe just going to 8's. Thoughts?

Nope.