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Discussion Starter #1
OK...I know nothing about 454's, this is my first....
I have a 21' Rochell Craft OB, Berkley JE, 454 Just rebuilt this thang, bottom end is stock as well as the oval port heads.
Mod's / upgrades during rebuild.
SLR Cam 218/228 .523/.532
Edelbrock RPM Air Gap Intake (already had a Edelbrock 750) / ditched the stock cast iron intake.
HEI 50K distributor / ditched the points / coil dist.
10qt Hamburgers Oil Pan

Timing set at 8 deg BTDC (don't quite know what the Advanced Vacuum is set at on HEI), plugs gapped to .045"...only getting 3k RPM's at 54MPH...is this all this slug will put out...?
Open to any and all comments suggestions and help...thanks in advance...!
I was doing better before the rebuild.

Diamond Dave
 

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First - get your timing squared away:

1. Put water to it.
2. UNPLUG the vacuum advance pot and plug the port (on the carb).
3. Loosen the distributor clamp a few turns.
4. Fire it up.
5. Use a timing light with advance dial - set it at 36*
6. Rev the motor and watch the balancer with the timing light. When it stops advancing, note the RPM. Probably 3000 or so.
7. If you let it back down - rev the motor to that rpm and twist the distributor until your balancer / pointer are at 0 (ZERO).

This will have you set at 36 TOTAL degrees of timing. Don't even worry about idle setting. Probably 38 or 40 is gonna be your end result, but start at 36 and make sure you are not pinging under a load. If not, go up a degree or two at a time until it pings. 38-39 is usually the magic number.

You can hook the vacuum advance back up after each setting. Just make sure you don't go to set it with it hooked up. You'll be WAY off. Also make sure the vac source is timed and not straight manifold vacuum. On an Edelbrock, it would be the port on the left front face of the carb. Left side being the side that has the throttle arm. You can also look into ditching the Edelbrock and put a Holley or Demon on it. If you want economy, you go Edelbrock - if you want power, you go Holley or Demon, or......

Make sure to tighten the distributor at least to where it will not rotate when running. You can also do it on the lake and just keep advancing a bit here and there until you hear it ping. This is a bit more dangerous, but being a low-per setup, you shouldn't hurt anything.

After you have your timing set, if it's not running well by then, move on to other things.
 

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Discussion Starter #3
Thx Beer 30
Running out today to get a new timing light....I had the Vacuum hooked up on the Right side of the Carb after setting the timing with my old school timing light. Again I can only get MAX 3K RPM....so after having done your recommendation with the new timing light should I be getting more RPM's...?

thx again....!

Diamond Dave
 

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Thx Beer 30
Running out today to get a new timing light....I had the Vacuum hooked up on the Right side of the Carb after setting the timing with my old school timing light. Again I can only get MAX 3K RPM....so after having done your recommendation with the new timing light should I be getting more RPM's...?

thx again....!

Diamond Dave
Wow, your timing is WAY WAY off, then. With the vac hooked to full-time source, your idle setting of 8 would be very retarded.

I would HOPE you would pull more than you had before - get the timing done first and then move on from there.

I am assuming the cam was installed straight-up? Not advanced or retarded?

Were the valves adjusted properly?
 

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only getting 3k RPM's at 54MPH...is this all this slug will put out...?
Your tach is crazy, 100% loco. Check to make sure its is on the right cylinder selection. When we were seling Beede's they would come preset on the 12cyl selection, we used to get this call a lot. A true 3000rpm is probably your plane speed. At a glance with no other info that bbc should turn around 4800 with an A or 4500 with a AA.
 

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Your tach is crazy, 100% loco. Check to make sure its is on the right cylinder selection. When we were seling Beede's they would come preset on the , we used to get this call a lot. A true 3000rpm is probably your plane speed. At a glance with no other info that bbc should turn around 4800 with an A or 4500 with a AA.
:))eek:)) At first I thought 12 cyl! Then the 6 cyl 2 stroke out board hit me:)sphss

You think 54 is a little much for 3000;)



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:))eek:)) At first I thought 12 cyl! Then the 6 cyl 2 stroke out board hit me:)sphss

You think 54 is a little much for 3000;)
Just pulled a nos tach off the shelf and it actually says "12palt", not 12cyl.....still wrong:)grn....if thats the case

Quite honestly 21' open bow with fairly stock BBC and a E pump, i'd say your sneekn up on your top speed at 54, ditchn the AFB for a Holley type carb should be worth some rpms and mph. But first thing is first, you need to get your tach workn.
 

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Good point(s) - no pun intended.

Get'erWet - if you haven't bought your timing light yet, make sure you get one with a tach built into it. This will help in all areas.
 

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Discussion Starter #9
Hay Beer :30,
Done got the Timing Light....Harbor Freight. Tach could be off...it's a 31 yr old boat. Before the rebuild of pump and motor top speed was about 57/58, don't recall RPM's B4 hand. "A" impellar put in but it was cut smaller AB...? I would think that I would get more RPM's with it...?
Set out for the Lake tomorrow for more testing...think I had a vacuum leak with carb gasket...removed the Spacer plate and installed new gasket. We'll see..........

Diamond Dave
 

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Hay Beer :30,
Done got the Timing Light....Harbor Freight. Tach could be off...it's a 31 yr old boat. Before the rebuild of pump and motor top speed was about 57/58, don't recall RPM's B4 hand. "A" impellar put in but it was cut smaller AB...? I would think that I would get more RPM's with it...?
Set out for the Lake tomorrow for more testing...think I had a vacuum leak with carb gasket...removed the Spacer plate and installed new gasket. We'll see..........

Diamond Dave
If its a two wire tach (ground and signal) it may not be compatible with the hei....thats about all i got on tachs:)hand
 

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Timing was definitely off and so is the tach. 3000 in that boat is no where near 54 mph. :)
 

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and plug the vac. advance completely! you don't need it, jetboat is always under load-you would never see any benefit from it!:D
 

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Discussion Starter #14
OK...so I've surely come to the conclusion that my Tach is Wacked...thx all for opening my eyes. New gauges on order. So I went and got a Dial timing Light....to make sure I do this right.
Plug Vac on both Carb & Distributor....Set dial to 36 deg run engine up to ???? RPM's and make sure balancer mark comes on zero deg.
Did a little adjustment on the water yesterday and then drove it like I stole it and got 60 mph out of her...I think she has a bit more in her...The guy that freshend up my pump changed out my "A" impeller and said the one he put in is a B minus...? Again, I know a lot of things but not a lot about all this....so having said that, once again N E advice is welcome..

Diamond Dave
 

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Set dial to 36 deg run engine up to ???? RPM's and make sure balancer mark comes on zero deg.
Did a little adjustment on the water yesterday and then drove it like I stole it and got 60 mph out of her...I think she has a bit more in her...The guy that freshend up my pump changed out my "A" impeller and said the one he put in is a B minus...? Again, I know a lot of things but not a lot about all this....so having said that, once again N E advice is welcome..

Diamond Dave
About the impeller - I have not one shred of info. Not a jet guy. Never had one.

So did you actually set the timing to 36? or do you have that to do still?

As far as the RPM to set it at - the point to keep in mind is - you are setting TOTAL timing. So, you have to set it AFTER the advance weights have swung out completely inside the distributor. This is usually anywhere between 2600 and 3500. Regardless of the dial on the end of the timing light, you can watch the balancer advance as you speed the motor up. So, to tell where YOUR distributor throws the weights out completely and provides TOTAL advance, you need to watch the balancer with the light and accelerate the motor find what RPM it stops advancing at. Then you can hold it at that RPM or HIGHER (won't matter after that) when you set the timing. NOW is when the dial on the light comes into play. If you had a fully-indexed balancer with timing marks etched into the surface, you don't need an advance light. You can just hit the light, dial the distributor until the "36" mark lines up with "0" or the sharp end of the pointer (if it doesn't have numbers).

Now, unless you spent some more coin for a fully-indexed balancer, you just have a "line" on the balancer and a pointer with a zero and some numbers fore and aft of it. The advance dial on the gun becomes your indexed balancer. Dial the number you are looking for, rev to the RPM (or more) that will give you FULL advance, and move the distributor until the line on the balance lines up with the "0".

All of this has to be done with the vac advance disconnected and preferrably, plug the port on the carb. Feel free to hook it back up afterwards. It probably won't be used much, but it doesn't HURT at all to have it along for the ride. Even if there is only 5" of vac, it will advance some more and only make the motor more efficient. At less vac than that, it is just leaving the distributor at your TOTAL setting. So again, it can't hurt anything to have it hooked up. Your choice.
 

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Max setting/ initial setting....

OK, setting the timing..... You need to understand that you have two settings... "initial", which is where you set the distributor, and "all in" (max) which is how much more the distributor advances as centrifugal force makes the weights move out against the springs..... So, if your initial is set at 12*,(vac un hooked) and you have 20* of advance "in" the distributor, your max would be 32*... Not enough according to the above posts...So, you will need to add heavier/different weights, and/or lighter springs to allow more advance "in" the distributor. Trying to run 18-20 degrees initial can, and will, tear up your starter, so you try to make the distributor advance from 12* initial, to the desired max of 36-38*, meaning you'll need to make the weights/vac pot advance the timing 24-26* above your initial..... Also, the springs hold back the timing, and the centrifugal force overcomes the spring tension as the Rs come up... The strength of the springs, and the weights determine WHEN the timing advances to max. Lighter springs, the timing is "all in" sooner, heavier springs, the "all in" comes at a higher RPM.... Are you getting any of this?? Or am I just rambling on and confusing you??>... "Curving" a distributor is an art, and a correct "timing curve" will make a world of difference in performance.... I strongly suggest you learn as much as possible about "curving", and do it yourself. Test your boat, and write down the results, try something a little different, ("all in" earlier/later) etc etc. I have a Mallory, Halls effect pick up distributor that allows me to set advance with micro switches. 1) When the timing advance starts, 2) how many degrees per 1000 RPM, and 3) maximum advance.. I can change these settings with the flips of switches.... You need to be able to do something very much the same, but with weights and springs, and maybe an adjustable vac pot...... It truly is a science, learn all you can, you'll thank me every time you nail the gas.......Your results, will be in RPMs, GPS speed, and most important, the "seat of your pants" feeling of acceleration... Unless you have a "G" meter, the seat of your pants is about the best way to determine if the ONE change you made helped, or hurt performance...OH yeah, change ONE thing at a time, test, write it down, make ONE other change, test, write it down.......(In other words, change one thing at a time and evaluate that change before you change anything else)....This relates to timing, jetting, impellers, loaders, valve settings, spark plugs, etc etc....Did I suggest you only change ONE thing at a time??

Ray
 

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Really??

E=MC2/5 carry the 2 X96+PI times the speed of light constant :)sphss

Its a jet! Kill the weights and lock it up at 36*
Won't that play hell with hot starts??? That's a lot of initial for the starter to over come...He'll tear up the ring gear, and bust the starter nose.... That would be the simplest, of course, but I have seen dismal failures without all sorts of retard boxes and "spin it and flip this switch" procedures.... I doubt he has enough cam overlap to bleed off compression while cranking....And it'll ping like crazy trying to get a heavy skier up.....

Ray
 

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OK...so I've surely come to the conclusion that my Tach is Wacked...
Did a little adjustment on the water yesterday and then drove it like I stole it and got 60 mph out of her...I think she has a bit more in her...The guy that freshend up my pump changed out my "A" impeller and said the one he put in is a B minus...?
A "B" impeller will allow your pump to spin higher rpm's, theoritically having more speed. A "B" minus could be a "B/C" cut impeller. if you pull skiers or tubers, then an "A" impeller is usually prefered. if speed is what your going for, then the "B" is fine. your doing good at 60mph, so if its not broken, then keep it the way it is. if you want alittle more speed, then you'll have to do some more motor and pump work to be safe.

with jet boats, you can either do one or the other. such as having your pump to run hard or to take a cruise. not many jet boats can do both, but there are a few.

i'd be happy with an open bow cruiser with speeds of 60mph.
 

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OK, setting the timing..... You need to understand that you have two settings... "initial", which is where you set the distributor, and "all in" (max) which is how much more the distributor advances as centrifugal force makes the weights move out against the springs..... So, if your initial is set at 12*,(vac un hooked) and you have 20* of advance "in" the distributor, your max would be 32*... Not enough according to the above posts...So, you will need to add heavier/different weights, and/or lighter springs to allow more advance "in" the distributor. Trying to run 18-20 degrees initial can, and will, tear up your starter, so you try to make the distributor advance from 12* initial, to the desired max of 36-38*, meaning you'll need to make the weights/vac pot advance the timing 24-26* above your initial..... Also, the springs hold back the timing, and the centrifugal force overcomes the spring tension as the Rs come up... The strength of the springs, and the weights determine WHEN the timing advances to max. Lighter springs, the timing is "all in" sooner, heavier springs, the "all in" comes at a higher RPM.... Are you getting any of this?? Or am I just rambling on and confusing you??>... "Curving" a distributor is an art, and a correct "timing curve" will make a world of difference in performance.... I strongly suggest you learn as much as possible about "curving", and do it yourself. Test your boat, and write down the results, try something a little different, ("all in" earlier/later) etc etc. I have a Mallory, Halls effect pick up distributor that allows me to set advance with micro switches. 1) When the timing advance starts, 2) how many degrees per 1000 RPM, and 3) maximum advance.. I can change these settings with the flips of switches.... You need to be able to do something very much the same, but with weights and springs, and maybe an adjustable vac pot...... It truly is a science, learn all you can, you'll thank me every time you nail the gas.......Your results, will be in RPMs, GPS speed, and most important, the "seat of your pants" feeling of acceleration... Unless you have a "G" meter, the seat of your pants is about the best way to determine if the ONE change you made helped, or hurt performance...OH yeah, change ONE thing at a time, test, write it down, make ONE other change, test, write it down.......(In other words, change one thing at a time and evaluate that change before you change anything else)....This relates to timing, jetting, impellers, loaders, valve settings, spark plugs, etc etc....Did I suggest you only change ONE thing at a time??

Ray
He's not ready for this yet. Let's get him through initial settings first. He can tweak all he wants once the motor is safe and timed decently.

Playing with springs and timing curves will likely come naturally as he plays with his total settings.

Good info, though.
 
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