streetrod56

I have just built a ls3 motor,12.5-1 comp, pro comp carb with Mast intake. the motor is in a 1950 chevy coupe I built a couple years ago. car is 3.000lbs power glide. I just started the motor the other day and it has no ***** at all, wont come up on the trans brake( lack of power) first of all could the intake and carb be to large to cause this? I sure hope not. it is run with a MSd.6012 box that I know nothing about at this time as I am used to the old ign. please any help.
I had hoped this motor to build around 600+ hp maybe I am out to lunch. hope this pic loads . it is the car.
https://www.flickr.com/photos/124212...8/14102440633/
https://www.flickr.com/photos/124212...8/14104217651/

ZONES89RS

iTrader: (25)

Did you tune the ignition yourself? If not, you need to.

streetrod56

I just found out that the cable that goes from box to lap top is not correct. going to radio shack in the morning. I am going to be lost with that also. lol
MDS used to be great product but now days they suck.
I am using a map sensor on it also, should I remove that?

streetrod56

another concern I have is crank case vent and vent for the oil tank. the motor only has a 3/8 in port in the valley cover nothing in the valve covers. what do you guys recommend?

Doug G

ZERO out the MAP as soon as you get the MSD to lap top plug. Don't use the MAP until you get it dialed in some. Also, do NOT use the pills that come with the MSD unless it's a stock build.
My valve covers are from a '04 Silverado and have a 3/8" nipple in each cover (front on one side and rear on the other side....nothing in the valley.

streetrod56

Thanks Doug for the response. do you have a pcv valve in it? where do the two lines hook to? Going to be a couple days before I can get back to hook to a lap top.

The stunningman

iTrader: (47)

[QUOTE=streetrod56;18231993]I have just built a ls3 motor,12.5-1 comp, pro comp carb with Mast intake. the motor is in a 1950 chevy coupe I built a couple years ago. car is 3.000lbs power glide. I just started the motor the other day and it has no ***** at all, wont come up on the trans brake( lack of power) first of all could the intake and carb be to large to cause this? I sure hope not. it is run with a MSd.6012 box that I know nothing about at this time as I am used to the old ign. please any help.
I had hoped this motor to build around 600+ hp maybe I am out to lunch. hope this pic loads . it is the car.

The bold is very likely due to detonation. Default is number 3 with no pill and every pill is to high in timing for a 12.5 to 1 engine IMO especially adding in any advance through map. As suggested by others You need to throw the pills away and start around 28 total after 2400 rpms. Flatline the map 0 and start the learning curve from there.

Bob S

If you run a pill without zeroing the advance curve it will load the pill's advance on top of the default in the box. You'll detonate it to death quickly! MSD doesn't tell you this in the install instructions.

It's good advice to throw the pills away, zero the map and set up your advance curve as suggested. Also, I've been told by a wise one...do not trust the box... Make a simple pointer, mark top dead center on the drive pulley and use a timing light. Boxes have been found way out of "whack".

Bob

Blazeracer

iTrader: (2)

Bull, I got a 12:1 pump gas motor with a MAF and any pill in the set will at least pull better than any Gen 1 small block that ever came out of GM. Shoot, will out power most stock big blocks too on any pill. The pills may not be ideal in all situations, but any of them will at least run pretty damn good. There's something else wrong.

I'd look at that ProComp carb first. Maybe the secondaries aren't opening. If it's crackin and poppin check that the coil plugs are on the correct side. My harness will plug in the wrong side on the coils, although I never did it to see what happenend. My carb is an 850 Demon on a 5.7 liter and screams jetted at 74 and 80. Cam's not retarded 4*, is it?? That's a power killer too. Maybe even a tooth off?? Doubtful, but possible....

I run mine in a jet boat and found that the oil return system sucks using the PCV. I just run breathers on either side with no issue. Bought a flat valley cover with no holes since I din't run knock sensors.

You just need a 9 pin to USB adapter to get the box to connect with a laptop.

Blazeracer

iTrader: (2)

My boat with pill number 6 on a 12:1 motor. Wife was a little late getting the camera going. The guy in the other lane had a diverter problem. This run is 71 mph. I can get 75 mph on custom tune I have posted up in another thread asking for some MAP help.

The stunningman

iTrader: (47)

Its amazing to see your engine with 12:1 compression can handle 48 degrees of timing that a pill with stock advance in it would crank out. I wonder how long it would last like that? I'm guessing you got the cord as to not find out.

I'm not sure how the load bearing goes on your boat, but I would think its more forgiving than the wheel to pavement.

I am sure you shouldn't be giving anyone timing advice. When giving advice on such, I would rather give them a low number and let them work their way up. Detonation would be just like smacking a piston(s) with a hammer and will definitely hold a engine back. Even destroy it.

streetrod56

Thanks for the info. I will be looking at these things next couple days.

sb50

iTrader: (1)

Not trying to hijack but I just got my engine fired a few days ago using a pill and your telling me that it has way more advance than just the pill? Yea I'm going to connect my laptop when I get other issues sorted out but just using a pill that advance setting is added to an internal default setting?

Doug G

I had it hooked up to the intake and after my first pass pushing out the dipstick and spewing a spray of oil all over motor and getting under the tires
I went to an oil/air separator
$60 ? on Amazon

on firewall where heater box would be. As it was said to me....PCV on a racecar

streetrod56

Thanks Doug, I have one on the way. when I removed the oil fill cap in the valve cover my oil leaks went away. have the timing all set now but the motor is still a big turd. don't know if the cam guy is full of s%#$ or what.

Pop N Wood

iTrader: (1)

I'm not sure how you came up with 48°. The pills in the 6012 box put 20° of vac advance on top of a max static timing of 23° for the #6 pill. A #3 pill only has 17° of static timing.

Interestingly the 6010 box runs a lot more static timing and only 4-6 degrees of max vac advance. Not sure why they changed it for the newer engines.

I think people go a little overboard talking down the pills. Definitely better to put in your own curve, but starting with a low number pill for initial start is safe while lots of guys run successfully on the pills alone. Think of all the Edlebrock boxes out there.

There are probably 100 things that could be causing the OP's motor to fall flat. Carb would be my first suspect.

streetrod56

Pop N Wood , I just talked to pro comp on the carb, I bought it used but just like new, it flowed 1120 cfm and could just be to large for this motor. Going to try to find another carb to try.
maybe the intake is to large also. I think I made a boo boo.

3pedals

iTrader: (3)

1120cfm is a BIG carb! But im willing to bet your 'lack of power' is timing and carb setup related. Im sure a 1000HP, or 850 would be a better choice.
I personally think a 850 Mighty Demon is the way to go

Bob S

P N W said, "I think people go a little overboard talking down the pills. Definitely better to put in your own curve, but starting with a low number pill for initial start is safe while lots of guys run successfully on the pills alone. Think of all the Edlebrock boxes out there."


Pop N Wood,

I agree, there is probably a pill to suit most applications fairly closely...but...if you just drop one in thinking you'll get the curve from that # pill you'll likely do thousands $ in damage. I feel like a fool for chasing my tail looking for all sorts of reasons why I broke the L76 I tried first. And it didn't stop there...!

It's moronic MSD does not spell out in bold red letters to zero the base curve before installing a pill!!! Do I sound Mad..?

Bob

fast89stang

iTrader: (2)

I ran mine with 34 degrees timing and map not zero'd out......i was sure glad I didnt hurt anything.