Performance Boats Forum banner
1 - 19 of 19 Posts

·
What the Hell is That?
Joined
·
1,633 Posts
Discussion Starter · #1 ·
So I found out my timing is locked out. What are the pro's and cons of having locked out timing? Also I read in another thread a guy has his locked out at 37* or 38* (SBC) mine is locked out at 27* for right now (SBC) maybe that's why its running like crap. It will run all day on the trailer idle, rev etc. but as soon as you dump it in the water and put a load on it it wont idle worth a crap. Could timing effect this? Why does it run fine on the trailer but when put a load on it, wont? What kind of load does a Jet pump put on a motor (the impeller is a "B" if that matters)

my thinking is its a slight load to the crank so the pistons/crank might move a hair slower but timing remains unchanged hence the no idleing. Hell I dont know im just brain storming.
 

·
Some guy
Joined
·
3,669 Posts
Idle speed will decrease in the water due to the load on the pump. To the best of my knowledge, you shouldn't really be running the engine with the pump dry.

Depending on your engine, I would probably consider 36 degrees max. I build a high compression small block that runs on race gas in a dirt car and we run it at 36.

Get the timing set where you want it before you bother to change the idle speed with carb adjustment, since it will increase when the timing is advanced.
 

·
Premium Member
Joined
·
992 Posts
If you are trying to set idle speed and mixture on the trailer, and expecting that to be correct when you drop it in the water, you are wasting your time. The pump does put enough load on the motor that those adjustments need to be finalized in the water.

Why are you only running the timing at 27* ?
 

·
What the Hell is That?
Joined
·
1,633 Posts
Discussion Starter · #5 ·
Idle speed will decrease in the water due to the load on the pump. To the best of my knowledge, you shouldn't really be running the engine with the pump dry.

Depending on your engine, I would probably consider 36 degrees max. I build a high compression small block that runs on race gas in a dirt car and we run it at 36.

Get the timing set where you want it before you bother to change the idle speed with carb adjustment, since it will increase when the timing is advanced.
Here is another question,

so the higher the compression the more advanced the timing? Say I'm running a blown 6.1 deal with 6lbs of boost. the lower the comp the more advance you can get in?
 

·
What the Hell is That?
Joined
·
1,633 Posts
Discussion Starter · #6 ·
I wasn't really playing with the carbs air/fuel i was more playing with the timing. I'm afraid of going to far on the timing to where I start melting shit. I guess sometimes i play it too safe. that day it ran really lean according to the plugs and the POP so i trailed it and decided to enjoy the rest of the weekend.

For what its worth i always set the idle high on the trailer and do the final adjustments on the water
 

·
Registered
Joined
·
63 Posts
set the timing at 32 if its running lean put some fuel in it and set the idle on the water and forget what it idles at on the trailer :D
 

·
Some guy
Joined
·
3,669 Posts
Here is another question,

so the higher the compression the more advanced the timing? Say I'm running a blown 6.1 deal with 6lbs of boost. the lower the comp the more advance you can get in?
I didn't see any mention of blower in the first post, forget what I said about 36 degrees.
Your avatar shows a carbureted engine.

You will want to make sure your carburetion and fuel delivery is all correct, and I tend to agree with your "safe" method, and also agree with 32 max for a blown application,, but maybe 30 is safer and able to make adequate power for your application.
 

·
Registered
Joined
·
46 Posts
Most conventional blown BBC stuff loves around 32 degrees. SBC's will usually take more. Remember too little timing will hurt as much as to much.

As to locked out timing I have only seen 1 motor benefit from NOT having it locked. It was on a ~900+HP NA 598" with tunnel ram and 2X1050 Dominators...he could not get the motor to idle down to a reasonable number to shift a bravo so he put a curve in it. Before, with 4150 carbs it was locked as well.

Locked timing helps motors start, idle, and run. I also feel it helps eliminate "surge" in roots blower applications...unless of course you like surge. It's also one less thing to maintain when the springs in the distributor freeze up over time.

Most NA SBC stuff run's 36-38 best...when you get into ~11:1 motors with Domes then you usually have to turn it up to ~42. Stock 500EFI's run 36 from the factory!
 

·
What the Hell is That?
Joined
·
1,633 Posts
Discussion Starter · #10 ·
Sorry I should have mentioned a blower app. (177) right now its over carbed and i need to fix some things in the fuel delivery that's why was on the safe side when i ran it last.

its just a mild Small Block at best. 332 (327 0.30) forged everything, low static compression, with a 177 set up for 6 lbs at the moment. Sorry if i mislead anyone.

 

·
Registered
Joined
·
20 Posts
Most conventional blown BBC stuff loves around 32 degrees. SBC's will usually take more. Remember too little timing will hurt as much as to much.

As to locked out timing I have only seen 1 motor benefit from NOT having it locked. It was on a ~900+HP NA 598" with tunnel ram and 2X1050 Dominators...he could not get the motor to idle down to a reasonable number to shift a bravo so he put a curve in it. Before, with 4150 carbs it was locked as well.

Locked timing helps motors start, idle, and run. I also feel it helps eliminate "surge" in roots blower applications...unless of course you like surge. It's also one less thing to maintain when the springs in the distributor freeze up over time.

Most NA SBC stuff run's 36-38 best...when you get into ~11:1 motors with Domes then you usually have to turn it up to ~42. Stock 500EFI's run 36 from the factory!

Why would you run more timing with 11:1 compresion? Would't you run less timing with more compression?
 

·
Registered
Joined
·
4,288 Posts
Why would you run more timing with 11:1 compresion? Would't you run less timing with more compression?
I don't want to put words in his mouth....usually with more compression comes more cam overlap.....I thought the amount of timing a motor would "like" had to do with things like overlap, open vs closed chamber heads, altitude, high octaine fuel vs low,ect....
 

·
Registered
Joined
·
302 Posts
Higher compression requires less timing, blowers sometimes like more than N/A, it depends on compression ratio and boost. TIMINATOR
 

·
Registered
Joined
·
1,640 Posts
It's a given your timing is too low at 27*. Since you have a blower motor, and some fuel delivery issues, it would be wise to creep up slowly. 30* would be a safe starting point, with increases at 2* increments. Check the plugs carefully each round until you find a good reading. It should start waking up with just a few adjustments.

BTW, why don't you descibe your fuel system issues and components...
 

·
Registered
Joined
·
46 Posts
Higher compression requires less timing, blowers sometimes like more than N/A, it depends on compression ratio and boost. TIMINATOR

Not NA. I should have clarified that with "domed" pistons and 110 octane you will need more ignition timing for 2 reasons, obviously it depends on the combo.

A) the higher the octane the slower the burn rate.
B) A high dome piston will need more timing because of the need for increased flame travel around the dome.
 

·
What the Hell is That?
Joined
·
1,633 Posts
Discussion Starter · #18 ·
How did you find out your timing was locked out? You sure it's locked out and you didnt just loose/break a spring?
I didn't know it was locked out. I was at Brian's (LuckyDayz) house and we were wrenching on it and setting timing. Ray (Moneypit) stopped by for some other business and he had a dial back timing light it was 25* through the whole RPM Range. Thats when we found out it was locked out.

It's a given your timing is too low at 27*. Since you have a blower motor, and some fuel delivery issues, it would be wise to creep up slowly. 30* would be a safe starting point, with increases at 2* increments. Check the plugs carefully each round until you find a good reading. It should start waking up with just a few adjustments.

BTW, why don't you descibe your fuel system issues and components...
The issues were bad fuel filter and the carb's were boggign down and stumbling near idel. it was flooding itself. Way to much Carb for the motor.
 
1 - 19 of 19 Posts
Top