Smoking Merlin 509 - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

 
LinkBack Thread Tools Display Modes
post #1 of 14 (permalink) Old May 28th, 02, 04:17 AM Thread Starter
Senior Tech
 
Join Date: Apr 2001
Location: Out here
Posts: 111
Ok guys I hope someone can point me in a direction that I have not looked. I'm stumped to say the least.

Last year I bought a Merlin 509 for my 69. Let me first say the thing runs great. Very drivable. Lots of power and no misses. The problem is it smokes all the time it's not a tremendous amount. I can't see any from the rearview mirror or anything. It doesn't have that oil type smell and doesn't really use any either. However, I can't really determine what color the smoke is. Grey is prolly my best guess.

Here are the specifics:
I live at 5800 ft. The motor is 9:1, The cam is a solid with 256 @ .050 and .579 lift. I'm running an 825 RS GC demon. I'm running a 4.5 powervalve on it. 2.125 primary Hooker headers flowing into 2.5 in. Flowmasters and an MSD 6AL ignition.
The timing is set to 20 BTDC initial and has all 36 in by 2500 rpm. engine vacuum is about 7-9 in/Hg at idle (1000 RPMs). Plugs are gapped to .55 and clean. Electrodes and ceremics are clean and there is very little carbon build up around the base. Threads on a couple have a little brownish goo. I don't think its oil. It has flooded a couple of times. Compression is 150 lbs on all eight. As far as temperature goes the thing always runs 200 and upon shut down it will rise to 210 and then cool off.

On the Demon I have the idle mixture screws set at 3/4 of a turn from seating. Anything more and the smoke is really bad. Anything less and its leans out and dies. I have .25 in. showing on the idle transfer slot. I've drilled two .0625 in holes in the primary which allows me to lean it further but the smoke persists. I have also opened up the idle bleeds to .078 in.

Fuel pressure sits at 7.5 lbs/in^2. Fuel level is BELOW the lowest line on both sights.

One more thing. I use castrol 20w50 and the color of the oil is nice and light brown on the stick.

This motor has about 2000 miles on it and has always done this even with the Holley that originally came on the motor.

New PCV and I retorqued the intake bolts. I've adjusted the lash. The only thing I have not done is replace the intake gaskets. The inside of the intake is completely clean.

Sorry for the long winded post but I wanted to be as detailed as possible.

Thanks in advance for helping me out.
psalm69 is offline  
Sponsored Links
Advertisement
 
post #2 of 14 (permalink) Old May 28th, 02, 09:51 AM
Senior Tech
 
Join Date: May 2001
Location: Austin TX USA
Posts: 501
Brother Psalm...since nobody has responded, I'll take a stab.

You say "it doesn't really use any oil"...how much oil are you using...how often and how much do you refill?

If it's quite a bit (quart per 1000 mi.) and your motor is new, I'd look for oil possibly being sucked into the intake runners between the intake and the head(s)...which means intake gasket r & r.

If little oil is being consumed, your fuel mix/carb needs to be looked at...perhaps the metering is too rich or floats are too high which might cause flooding. You say your engine runs fine so this diagnosis may not fit.

Longshot, but perhaps coolant is being sucked into the combustion chamber?...again between the intake and head(s).

What does the inside of your tailpipe look like?
Sleepy-69 is offline  
post #3 of 14 (permalink) Old May 28th, 02, 10:43 AM Thread Starter
Senior Tech
 
Join Date: Apr 2001
Location: Out here
Posts: 111
Thanks for the reply. The tail pipe is powdery black. I'm wondering if maybe the fuel bowls are some how being pressurized. I've always had the BG super speedway mechanical pump with -8AN line. Recently I put a regulator on with no results. Same smoke. Wanna buy a camaro?
psalm69 is offline  
 
post #4 of 14 (permalink) Old May 28th, 02, 03:15 PM
Senior Tech
 
Join Date: Apr 2002
Location: Seattle, WA
Posts: 176
I guess I'll chime in...the 150 psi on all cylinders concerns me...it seems it should be higher especially with a new motor, the compression consistency between the cylinders is good however. Sounds like you have clean plugs....which tells me its not excessively rich and the oil burn does not seem to be excessive. Since the same problem exists with two different carbs, I am going to list some ideas other than a carb/fuel issue.

Are you noticing most of the smoke after start up or while driving? If your noticing the smoke mostly after start up it could be leaking valve stem seals or maybe one of the valve stem seals lost its position somehow. After engine shut down, oil will leak down the valve stem if the seal is bad and sit in the chamber, then on startup the oil gets burned and you'll notice some smoke.

Another thought, you might have a leaking head gasket. THis would cause your compression readings to be low (which it seems to me they could be low at only 150 psi). You could be getting a little water and oil in the combustion chambers causing a steam/smoke mix out the tailpipes. Water in the combustion chamber will in effect "steam clean" your plugs; making them look clean...eventhough there is a combustion problem.

Check to see if you have some water in the oil....or some oil residue in the coolant. This would indicate a leaking head gasket. I would also look at re-torquing your head bolts...maybe the head bolts are a little loose after the engine break-in causing some coolant or oil to seep past the head gaskets.

Your engine coolant temp running at 200 seems a bit high to me, what kind (temp) of thermostat do you have? If your having semi-overheating problems...this could be the result of the leaking head gaskets.

If you can, and the problem persists, maybe spend some time and pull one head and have a look at the head gasket and combustion chambers.

Just some thoughts on what it could be. Good luck in your diagnosis.
esahlin is offline  
post #5 of 14 (permalink) Old May 28th, 02, 05:53 PM Thread Starter
Senior Tech
 
Join Date: Apr 2001
Location: Out here
Posts: 111
The amount of smoke that I have is constant. It doesn't matter whether the motor is cold or not. And like I was saying before It isn't like there is this huge cloud or anything. It's just enough to annoy. I wonder if maybe I'm just being to anal and this type of setup especially at this altitude is just gonna have a bit of exhaust. Thoughts?
psalm69 is offline  
post #6 of 14 (permalink) Old May 28th, 02, 06:45 PM
 
Join Date: Apr 2001
Location: Yakima, WA 98908
Posts: 28
It is also possible that the rings are not seated yet. Sometimes it takes several thousand miles. Also the idea about the temps could have something to do with forged pistons. They take awile to expand with heat.
NOMANRS is offline  
post #7 of 14 (permalink) Old May 29th, 02, 12:43 AM
Super Moderator
Bess-68's rule
 
Everett#2390's Avatar
 
Join Date: Sep 2000
Location: Va Beach VA
Posts: 31,622
Garage
Alot of good suggestions here, I'll try with my two cents.

I would say, with the amount of vacuum, oil is being sucked into the combustion chamber. Valve stem seals are very good source. But, these would be more noticeable when throttle is opened up.

I would do a cylinder leakage test. This will show 1) how much cylinder is really sealed, 2) if there is a gasket leaking, see bubbles in coolant.

If cylinder is not sealed good, you'll hear air escaping either at: a. carb, intake valve leaking, b. tailpipe, exhaust valve leaking, c. crankcase (oil fill tube/cap), leaking past rings, d. coolant.

A temp of 200 degF is not bad, hoses are tight, and it doesn't boil over.

I am on the side of the fence with a couple others here, rings may need to be seated. I'm sure you've broken it in correctly, 20-60 mph, WOT, in high gear, then coast to 20, repeat previous 10-12 times.

I would suggest this, go to a GM dealer and get a can of EOS, Engine Oil Supplement. It's made for new camshaft break-in and new engines. I use it in my '68 and Dually, a helluva alot better than STP oil treatment. I bet it will decrease comsumption, 1 quart/1K miles is good, when you start leaving an oil trail from the tailpipe, then it is a problem.

If the EOS helps reduce the oil consumption, then it's the rings.

Let us know what you find out,

------------------
Everett 68/350/PG/11.90/115mph

[This message has been edited by Everett#2390 (edited 05-29-2002).]
Everett#2390 is offline  
post #8 of 14 (permalink) Old May 29th, 02, 03:44 AM Thread Starter
Senior Tech
 
Join Date: Apr 2001
Location: Out here
Posts: 111
Thanks for the advice guys. I'll try a leakdown test. I've never used one before is it something that I can grab at the local autozone?
psalm69 is offline  
post #9 of 14 (permalink) Old May 29th, 02, 06:20 AM
 
Join Date: Apr 2002
Location: Huntington, NY, USA
Posts: 9
Here are my two cents:
First, your CR should be up at around 180 minimum. Make sure you have the throttle wide open when spinning the motor.
Second, most racing engines (and even modern day cars such as BMW)have a certain amount of oil consumption. One quart every 4,000 to 5,000 miles is normal.
jg67 is offline  
post #10 of 14 (permalink) Old May 29th, 02, 07:33 AM Thread Starter
Senior Tech
 
Join Date: Apr 2001
Location: Out here
Posts: 111
So I called the World guys and the spec they gave me for compression was 150-155 lbs/in^2. So I'm right in line on that one. Here's a thought I had. They call for a .035 gap on the plugs. Per MSD I have mine set to .055. I'm wondering if the gap is too wide and as a result I'm not getting quite the complete burn. When they run those motors in they are equipped with an HEI ignition. I had to remove mine because of interference with the firewall. Thoughts?
psalm69 is offline  
post #11 of 14 (permalink) Old May 29th, 02, 09:37 AM
Senior Tech
 
Join Date: May 2001
Location: Austin TX USA
Posts: 501
I'd give the plug gap a try, but put it on the longshot list.

150 compression on all 8 doesn't bother me...not on a 9:1 compression motor, with some duration on the cam.

If I were a gambling I'd say your head gaskets are ok. I'd put my money that the intake gaskets aren't sealing on the lower part of the intake port(s), and oil is getting sucked into the combustion chamber.

Good luck and let us know.

Sleepy-69 is offline  
post #12 of 14 (permalink) Old May 29th, 02, 10:11 AM
Senior Tech
Ray
 
Join Date: Sep 2000
Location: Central FL
Posts: 271
I'm having a similar problem, large embarrassing puff of smoke on startup, but not every time, and small puffs when shifting. (You can see my post also under trouble shooting.) I suspect intake gasket or valve seals, and have confirmed it's not the PCV.

Are leaking intake gaskets a common thing? Is there a way to confirm the intake gasket is leaking before replacing it?

The valve seals and guides are less than a year old, so hate to think it's either of those.


------------------
Ray

68 SS Convertible
Corvette(77) Yellow
383 w/DFI Fuel Injection
on MiniRamII intake,
Trick Flow heads
Tremec 5 sp, 3.31 12bolt Posi
Guildstrand Mod
AGR 12:1 power steering
Bent short steering arms
Baer 13" front brakes (Couldn't find time to make my on bracket)
550# Hypercoils with Landrum height adjusters

http://www.geocities.com/hrayhouston/
68SSConvt is offline  
post #13 of 14 (permalink) Old May 29th, 02, 02:00 PM Thread Starter
Senior Tech
 
Join Date: Apr 2001
Location: Out here
Posts: 111
You know I have to wonder if maybe the symptoms of which we speak are just inherant to these types of motors. I know that I have gotten so used to how the newer engines are considerably cleaner. We have to think that these things are gas guzzling pigs with zero emissions. I guess in short perhaps the things are supposed to smoke a little.
psalm69 is offline  
post #14 of 14 (permalink) Old May 31st, 02, 01:43 PM Thread Starter
Senior Tech
 
Join Date: Apr 2001
Location: Out here
Posts: 111
So I pulled the intake. Covered in oil. The crazy thing is. Stupid motor has only 2000 miles on it. Valves are covered. Looks like it has been on the road in Kenya for 200,000 miles. So the moral here is if any of you guys get a crate motor double check everything.
psalm69 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome