Engine is in, successful run?

[Nextelbuddy]

All right engine is in.

Removed blown non vortec 350 and replaced with fresh full rebuild 350 5.7 vortec.

We use the timing lights at the thunderbolt 5 ignition and base timing mode and set it to 10° initially and my engine builder said he felt comfortable with 13° BTC so that's what we set it at.

Then we took it out of base timing mode and put the revs at 3,500 RPMs we're seeing about 25 degrees of total advance.

They said we could go up to 30 but I said let's be comfortable and safe so we left it at 25° total advance.


Boat:
- 1996 Sea Ray 210 bow rider
Engine:
- 1409 Edelbrock carb 600 CFM
- summit racing vortec intake manifold
- Comp cam Marine cam
- vortec heads
- alpha 1 Gen 2 1.62 gear ratio
- quick silver stainless 14.25x19p 3 blade prop (a few dings)

Max RPMs of 4700-4800 RPMs and gps verified 50mph. Boat definitely got out of the hole quick and got on plane easily. Reached max RPM with ease almost too easily

Since this is a vortec engine, do I still have to abide by the 4400-4600 rpm range of the older non vortec engines? Or can I go up to 5000 RPMs?

Asking because I want to change my prop out just want to figure out which prop to go to and how it will affect my max RPMs

Was really hoping to hit 55mph in this boat with this new engine.

 

[achris]

The maximum rpm are to do with where the engine is making maximum power. And that's usually based on, mostly, the camshaft. And all you said in your description was 'Comp Cam marine cam'. Comp Cam make 3 different cams for that engine. Which one do you have?

 

[Nextelbuddy]

The maximum rpm are to do with where the engine is making maximum power. And that's usually based on, mostly, the camshaft. And all you said in your description was 'Comp Cam marine cam'. Comp Cam make 3 different cams for that engine. Which one do you have?

thanks for the reply, here are the specs from summitt racing website'

Brand:
COMP Cams
Manufacturer's Part Number:
08-416-8
Part Type:
Camshafts
Product Line:
COMP Cams Xtreme Marine Camshafts
Summit Racing Part Number:
CCA-08-416-8
UPC:
036584038382
Cam Style:
Hydraulic roller tappet
Basic Operating RPM Range:
1,000-5,000
Intake Duration at 050 inch Lift:
212
Exhaust Duration at 050 inch Lift:
218
Duration at 050 inch Lift:
212 int./218 exh.
Advertised Intake Duration:
264
Advertised Exhaust Duration:
270
Advertised Duration:
264 int./270 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:
0.488 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:
0.495 in.
Valve Lift with Factory Rocker Arm Ratio:
0.488 int./0.495 exh.
Lobe Separation (degrees):
112
Computer-Controlled Compatible:
No
Grind Number:
CS XM 264HR-12

 

[Rick Stephens]

Good cam for that. I would run it at 5000 if the prop allows good hole shot. Might have to vent the prop for low end lugging prevention. Should be doable.

Be careful adding timing advance. A little pinging on a motor that runs under 100% load will eat pistons.

 

[Nextelbuddy]

Good cam for that. I would run it at 5000 if the prop allows good hole shot. Might have to vent the prop for low end lugging prevention. Should be doable.

Be careful adding timing advance. A little pinging on a motor that runs under 100% load will eat pistons.

im currently running a 14x19p prop quicksilver stainless. noting fancy and definitely not perfect.

if i'm running 4800 rpms with a 14x19p, what would going to a 14x21p stainless do, go up to 5000 rpms or go down to 4600 rpms?

 

[Rick Stephens]

if i'm running 4800 rpms with a 14x19p, what would going to a 14x21p stainless do, go up to 5000 rpms or go down to 4600 rpms?

It will go down several hundred RPMs. Play around with the Mercruiser Prop Slip Calculator and you can get an idea of where to take things.

 

[Rick Stephens]

BTW, when I run your numbers I get 6% slip, which is as good as it can get.

 

[kenny nunez]

Is the fuel pump being controlled through a oil pressure safety switch?
If not should the carburetor “flood over” and the engine stops then the fuel pump will keep pumping and a fire could result.

 

[achris]

I've also run your numbers through my own prop calculator, and something looks slightly off. The angle of attack is too low, especially for a boat of that size. And I would expect the slip to be between 10% and 15%.

This suggest a few possiblities. Were the engine revs being monitored with a shop/digital tacho, or just the dash tacho? (Dash tachos are notoriously inaccurate, especially in the upper range). I did see you have GPS speed, so that rules out an incorrect speed reading. Are you sure of the gear ratio? Most V8s are 1.5:1, and when I plug that in, the slip is 13%. If I 'correct' the RPM (with a drive ratio of 1.62), it looks like it might be closer to 5,200rpm....

What prop pitch changes mean is about a 200rpm/1" of pitch. So going from 19" to 21" will DROP the max rpm around 400rpm. To increase rpm, DROP the pitch. Going to 17" will raise the rpm to around 5200. But when you're close to the maximum rpm changing pitch won't change your top speed by much, maybe 1 or 2 knots at best.

 

[Nextelbuddy]

Is the fuel pump being controlled through a oil pressure safety switch?
If not should the carburetor “flood over” and the engine stops then the fuel pump will keep pumping and a fire could result.

Yes yes lol you guys love looking for anything that's possibly not marine and pointing it out.

I have many many other thread on here I made over the last 2 weeks and one of them was about wiring for fuel pump relay and oil pressure safety switch.

I have oil pressure safety switch wired up with a 30amp relay to the starter as well and inline fuse on fuel pump power line

An yes i did use marine rated 3/8 fuel like from west marine.

 

[Nextelbuddy]

I've also run your numbers through my own prop calculator, and something looks slightly off. The angle of attack is too low, especially for a boat of that size. And I would expect the slip to be between 10% and 15%.

This suggest a few possiblities. Were the engine revs being monitored with a shop/digital tacho, or just the dash tacho? (Dash tachos are notoriously inaccurate, especially in the upper range). I did see you have GPS speed, so that rules out an incorrect speed reading. Are you sure of the gear ratio? Most V8s are 1.5:1, and when I plug that in, the slip is 13%. If I 'correct' the RPM (with a drive ratio of 1.62), it looks like it might be closer to 5,200rpm....

What prop pitch changes mean is about a 200rpm/1" of pitch. So going from 19" to 21" will DROP the max rpm around 400rpm. To increase rpm, DROP the pitch. Going to 17" will raise the rpm to around 5200. But when you're close to the maximum rpm changing pitch won't change your top speed by much, maybe 1 or 2 knots at best.

What makes you doubt the results? Do you think Should speed be higher? Rpm be higher? Lower?

i know I have a 1.62 as it says that on the actual outdrive and the outdrive serial also pulls up a 1.62 ratio. I Madea profile on sea ray website and plugged in my serial numbers and it says this

ENG: 0F760044 457B100JS MERCRUISER 5.7L ALPHA
DRV: 0F693018 5010162JS MERCRUISER ALPHA 1.62:1
TRN: 0F650239 6010000JS MERCRUISER ALPHA TRANSOM


currently it feels like the boat wants to go higher than 4800 but something is holding it back. It gets up to 47 real quick and then hits 50 @4700-4800 using the boat tach.

not sure many people Carry around shop tachs these days for testing.

 

[achris]

What makes you doubt the results? Do you think Should speed be higher? Rpm be higher? Lower?

I doubt the result for a couple of reasons. VERY unusual to see such low slip on a boat that size. Normally a 6% slip would be seen on a VERY light, flat bottom boat, not a vee-hull twenty something footer. And I have a prop calculator I wrote and use... It's saying the same thing. (screenshots below)
As I already said, I think either the tacho is reading low, or you have a 1.5:1 drive ratio.

i know I have a 1.62 as it says that on the actual outdrive and the outdrive serial also pulls up a 1.62 ratio. I Madea profile on sea ray website and plugged in my serial numbers and it says this

ENG: 0F760044 457B100JS MERCRUISER 5.7L ALPHA
DRV: 0F693018 5010162JS MERCRUISER ALPHA 1.62:1
TRN: 0F650239 6010000JS MERCRUISER ALPHA TRANSOM

Still not convinced. That's a 15+ year old drive, which was originally delivered with a V6 in front of it. It's quite possible someone has pulled the V6 and dropped the V8 in, and changed the gears inside the drive to suit the V8. Until you either lift the top cap and count the teeth, or pull the drive and count turns, you only THINK it's 1.62:1.

currently it feels like the boat wants to go higher than 4800 but something is holding it back. It gets up to 47 real quick and then hits 50 @4700-4800 using the boat tach.

How the boat 'feels' isn't a good indicator. I was testing props a few months ago, and a 19" 4 blade felt really good, pulled strong (didn't bog down), but only got me to 4550rpm, so it was too tall (too much pitch). Without a tacho, I'd have thought that prop was the right size...

not sure many people Carry around shop tachs these days for testing.

Doesn't need to be a shop tacho. The digital readout on any half decent advance timing light is plenty good enough...

Chris.......

My prop calculator screenshots.
Data as supplied..


Adjusting drive ratio to 1.5:1

 

[Nextelbuddy]

I doubt the result for a couple of reasons. VERY unusual to see such low slip on a boat that size. Normally a 6% slip would be seen on a VERY light, flat bottom boat, not a vee-hull twenty something footer. And I have a prop calculator I wrote and use... It's saying the same thing. (screenshots below)
As I already said, I think either the tacho is reading low, or you have a 1.5:1 drive ratio.

Still not convinced. That's a 15+ year old drive, which was originally delivered with a V6 in front of it. It's quite possible someone has pulled the V6 and dropped the V8 in, and changed the gears inside the drive to suit the V8. Until you either lift the top cap and count the teeth, or pull the drive and count turns, you only THINK it's 1.62:1.

How the boat 'feels' isn't a good indicator. I was testing props a few months ago, and a 19" 4 blade felt really good, pulled strong (didn't bog down), but only got me to 4550rpm, so it was too tall (too much pitch). Without a tacho, I'd have thought that prop was the right size...

Doesn't need to be a shop tacho. The digital readout on any half decent advance timing light is plenty good enough...

Chris.......

My prop calculator screenshots.
Data as supplied..
View attachment 346495

Adjusting drive ratio to 1.5:1
View attachment 346497

interesting theory you have there sir.

I highly highly doubt anyone went through the trouble of changing out gear ratios and leaving the original gear casing in tact with stickers. not with the backyard people i bought mine front.

most likely its the tach reading being off thats throwing your app in a whirl wind.

when ever i get some time ill go out and purchase an aftermarket tachometer and hook it up to #1 plug wire and compare it to the in dash tach on the boat. most likely its off and i'm siting at a higher RPM than i thought.

if that the case then that means i can drop down to a 14x21p (my boat originally came with a 13.75x21p anyways according to sea ray) and that would drop my RPMs down to 4800ish or maybe still maintain the same RPM but higher top speed which is what i want.

 

[Rick Stephens]

Something ain't right.

 

[Scott Danforth]

boat could have been setup for high altitude with a 1.62 drive

or it could have originally had a 5.0 as SeaRay often paired the 1.62 with a 5.0

easy to determine, pull plug wire, crank engine 10 revolutions, how many turns does the prop make?

the 210 for 96-2002 and its smaller 190 sister were tanks with the 190 weighing 3000 dry (about 3600 wet with gear and the 210 weighing 3300 dry about 4000 wet with gear). however my 190 often saw 49.5mph on the GPS with a 1.62 running a 15 x 19p stainless while turning 4800 RPM

if you have the 1.62 drive, you should be running a 21p prop or greater

with vortec heads, I would not be concerned about detonation at the low base timing, however something is not right, you should be all-in on timing advance at 3500 RPM, so assuming a 22 degree advance curve, you should be showing 35 degrees, and not 25 degrees. that would indicate that the TB-V is pulling back on timing. do you have the knock sensors?

 

[Nextelbuddy]

boat could have been setup for high altitude with a 1.62 drive

or it could have originally had a 5.0 as SeaRay often paired the 1.62 with a 5.0

easy to determine, pull plug wire, crank engine 10 revolutions, how many turns does the prop make?

the 210 for 96-2002 and its smaller 190 sister were tanks with the 190 weighing 3000 dry (about 3600 wet with gear and the 210 weighing 3300 dry about 4000 wet with gear). however my 190 often saw 49.5mph on the GPS with a 1.62 running a 15 x 19p stainless while turning 4800 RPM

if you have the 1.62 drive, you should be running a 21p prop or greater

with vortec heads, I would not be concerned about detonation at the low base timing, however something is not right, you should be all-in on timing advance at 3500 RPM, so assuming a 22 degree advance curve, you should be showing 35 degrees, and not 25 degrees. that would indicate that the TB-V is pulling back on timing. do you have the knock sensors?

I wasnt using a shop tachometer. We were just using an older analog snap on adjustable timing light and the tach on the dash.

to be honest i'm pretty sure the tach on the dash was closer to 3200 rpms and given that those are most likely inaccurate it was probably really closer to 2800-3000 rpms


i can make plans to use the same timing light and get a shop tach and get a more 100% accurate read out but for now the engine seems to be running very well. no hesitation, starts every time, holds nice idle at 850 when warmed up and netting a 47-50 mph per gps which for now is plenty to just enjoy. im sure i will be cruising more at around 25-30 mph with the family in the boat

after this weekend ill pull a few plugs and check the color of them as well.

 

[Nextelbuddy]

Finally got an engine cover that I was happy with.. I was really hoping that it would have the right spark plug spec on it for MR43LTS because it says 350 Magnum on it.. but unfortunately it still says MR43T.

I wanted it to be as correct as possible so that if I decide to sell this boat in the future the next owner who may not be as privy to information like people like us will be able to just look and get the right information off the engine cover.

But she sure does look much prettier with the right engine cover and I also put a proper flame arrestor on it a much taller one for the 350.