Max rpm 2800

rossjo · Post by **rossjo** » Thu Mar 03, 2011 7:13 am

Per our conversation last night Larry, lets hook up a small tank to the fuel pump and try it. This will eliminate the tanks and "old" gas.

You're distributor sounds good, as you're getting 35deg Advance centrifugal timing, so it sounds like fuel.
Chrysler BB Firing Order:

per http://boxwrench.net/specs/bchrys_B.htm

BB Chrysler distributors turn CCW, which is Opposite GM motor' CW, so don't let me near the distributor! I think all your experience with race cars was probably Chevy - so we've got to remember that!

I have a Strobe Tach we can use (stick a piece of reflective tape on balancer) to check RPM, as well as temp guns, etc.

Let's get it running 4,000 RPM in neutral before we worry about props, tanks, etc.

The tank issue is another nightmare.

I didn't get your pix - maybe the email was > 20MB?

I can help you tomorrow or over the weekend, but going to help keep Titleist stay in business today with a round at Wild Dunes Links course.

plansea · Post by **plansea** » Thu Mar 03, 2011 11:08 am

Thanx for all the suggestions. I had to help a buddy all day yesterday, will be back on the boat today. The mallory spec sheet says it will give me 24 degrees of advance at 3000 rpm, therefore i have my timing set at 10 degrees btdc. I read somewhere that i needed 35 degrees total. With this setup i get 35 at about 24 to 2500 rpm. I am very anxious to get my new test tach, my old ones could be ,as suggested, way off. Pls note prop size is 20X20. I can only make about 17 to 18 MPH (15-16 nots). I will check firing orders, (again). Thanx so much for all this interest. Larry

captainmaniac · Post by **captainmaniac** » Thu Mar 03, 2011 12:35 pm

I think base timing for my 383's is 2 1/2 degrees before... will see if I can find any specs at home for a 280HP 400 (I have a couple of shop manuals). One other thought - are you checking timing by the water pump, or at the flywheel? If something has ever slipped or been installed offset, timing might be nowhere near where you think it is.

Big D · Post by **Big D** » Thu Mar 03, 2011 5:33 pm

Something doesn't sound right to me. You need to get a hold of the proper advance spec for the engine, Chrysler spec not Mallory. That much advance at only 2500 RPM doesn't sit well with me. I would expect to see that well over 3000. Be carefull here, you don't want detonation. Anybody else not comfortable with these numbers?

Geoff R · Post by **Geoff R** » Thu Mar 03, 2011 5:46 pm

M400 is 5 inital +21 @ 2200 26 total 35 won,t do 2800 in neutral
Chrysler mixes up the engine and prop rotations cw is a left hand engine depends on what manual you check

Geoff R · Post by **Geoff R** » Thu Mar 03, 2011 6:18 pm

[quote="prowlersfish"]Are sure a 280 hp will turn a 20x21 ? thats the prop often used with a 330 hp I believe

These are what I believe came factory the spares are the same 2 to 1 reduction i think
Chrysler Marine/Industrial was always very conservative with HP #s I can turn 20 x 21s at 3800 aprox 25 kts pretty much stock to get to 4000 open up the water passages in the risers Hi volt coils and re jet secondaries But OH Baby you dont want the fuel bill

Aaron was kind enough to post this earlier
http://dl.dropbox.com/u/10877359/1975%2 ... 0Sheet.pdf

Big D · Post by **Big D** » Thu Mar 03, 2011 6:41 pm

Geoff, I'm a little more comfortable with your timing/advance/RPM spec.

captainmaniac · Post by **captainmaniac** » Thu Mar 03, 2011 6:53 pm

My shop manual agrees with the 5deg initial setting. I only have progressive settings though for the 340... not the 400 ... so can't confirm the curve Geoff is describing, but if not right its probably pretty close.

plansea · Post by **plansea** » Thu Mar 03, 2011 10:30 pm

Thanx again all. My manual also says 5 degrees at 550 rpm, it does not however give me any spces for higher rpm. I will try retarding to 5 and see if that works. Can 5 degrees at idle make that much difference?
I knew my boat had issues when i bought the thing, it came with no log books and very few records. It runs so dawg-gone good at lower rpm Iam just amazed that it wont make horsepower at higher rpm. I new I had a can of worms, but didnt know i had a whole bucket! But as someone here likes to say "all things can be fixed!"
Today I checked the firing order on both engines and found them all to be correct EXCEPT . My starbord engine is a M400BWR19/596,which means it is a right hand engine and looking at the front it turns c w and firing order is 184346572. Port is M400BWL19/595 and again looking at the front it turns ccw and firing order is 12756348! Is this correct? Or am I even more confused? Is it possible that these things have been reversed? Would they run like that? I have a 1.91 velvet drive with a reverse gear. the props do turn the opposite direction of the engine.
On a little different note, I still cannot get the spare plug removed from the tank top, but when I do (and I will) I'll simply plug the old one and make a new pick-up tube for the spare opening. Larry
.

Big D · Post by **Big D** » Thu Mar 03, 2011 10:41 pm

Larry, unlike an automotive application, in marine, engine rotation is determined by looking at the engine from the back (at the flywheel) So your strb engine is righthand (R in serial #) rotation (CW) firing order 1-2-7-5-6-3-4-8. Your port engine is lefthand (L in serial #) rotation (CCW) firing order 1-8-4-3-6-5-7-2. Both distributors rotate CCW.

rossjo · Post by **rossjo** » Fri Mar 04, 2011 10:58 am

Larry,

Did you try the small tank of new gas? Get over 2800RPM?

I'm open today if you need someone to think through this with.

Yesterday was a brutal day of golf with steady 20-40 knot winds off the ocean ... 4 iron to go 140 yards into the wind - and a Pitching wedge would float and almost come back to you!

plansea · Post by **plansea** » Fri Mar 04, 2011 7:43 pm

Big D , you are of course exactly correct. For whatever reason I did discover ,after more closely reading my manuel , that my particular engines L 19 and R 19 ,because of the reverse gear,do turn as you said, But the firing order is the opposite.
Capt Ross,I had to make an appearance at the ole salt mine for a short time today so I did not get to try out the gas can idea. I was sucessful in gettig the "extra" plug out of the gas tank though. Tomorrow afternoon I'll assemble a new fitting with a new pick-up tube and get that installed. After that I'll get back to the original problem. 1st I'll reset the timing at 5 degrees and see if that works. I did receive my new test equipment today so I will be able to determine the accuracy of my tach. After that I will try the small gas tank. Once again many thanx to all of you guys, it just proves you can teach an old dog (guy) new stuff! Larry

jimbo36 · Post by **jimbo36** » Sat Mar 05, 2011 7:41 am

Plansea, How did you plug the original fitting on the gas tank? First thing I will be doing when I get to my boat is checking for this "extra" fitting you guys speak of.

jimbo36

rossjo · Post by **rossjo** » Sat Mar 05, 2011 8:18 am

"my new test equipment" is a strobe tach? Let me know if you need mine ...

Out of pocket today again though - golf @ 10 ...

Big D · Post by **Big D** » Sat Mar 05, 2011 10:47 am

Eureka! Ok Larry, did some digging. The firing orders weren't making sense to me. I knew there was an exception but couldn't remember which model. I confirmed as you described the exception to the firing order per Chrysler info is the L19 and R19 models. The firing order is opposite to accomodate the design of the Warner 1.91:1 reduction gear which turns opposite to engine rotation.