smoking 340

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brodphish

brodphish

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I have a 67 Barracuda with a professionally built 340 that has been bored and stroked to 417 cubes. Dyno'd at 471 HP 533 torque and it appears to make every bit of that, easily lighting up both big BF Goodriches through a Sure Grip rear end.

The motor was built in late 2006 and all indications it was run little if at all until I bought the car in early 2011. I've put about 250 miles on it and blows blue smoke especially over 2000 rpm, when it blows alot. Of course there is excessive oil consumption.

The number 4 cylinder fouls periodically but the other pluga have a normal burn pattern.

Any comments on hte most likely cause and the most efficient way to diagnose and fix this would be most helpful. I plan to have a well respected engine shop to the work but want to informed when I take it in.
 
I honestly don't think the motor has enough time on it to have damaged the rings unless they were severly damaged during an itinial dry fire after sitting so long. I was wondering if the intake gasket was damaged - to me that seemed even more likely than a valve steam/seal problem even though I've never heard of it.

Boss if you would not mind, what exactly does that mean and is the fix as simple as replacing the intake gasket? Can it cause leakage into a single cylinder?

I appreciate any input - the car's power output is a total beast but obviously something needs to be fixed.
 
The rings might have taken a set in the bores from sitting so long, and it might take a bit before they reseat. It's either that, or as said earlier the rings are shot, or the # 4 cylinder may have a broken ring. JMHO

Bill S.
 
i would check that intake gasget its an easy check and maybe an easy fix good luck
 
If the rings did take a set in the bores how many miles would you expect before it would be apparent things have smoothed out and the smoking stops?

It's been unusually nice here in Chicago (+45 and 50 degrees) so I've taken the car out twice and the the smoking seems like it's slowed a bit. Still lesss than 300 miles on the motor.
 
PS I took a look at the intake gasket today and the excess was cracked vertically between both 3&7 and 4&6 down to the mating surfaces. It looked like the cracks may have extended between the mating surfaces but could not tell for sure.
 
Man just yank the intake and replace the gasket. I like Fel Pro print o seal and with a steel core, part number ends with an S. You think the top looks bad wait till you see the bottom, that is where the oil is being suck from in to the ports

Jegs or Summit should have the 340 big port gaskets in stock for around $40--you can reuse the gaskets, just seal it to each head and nothing on the intake-print o seal side. You never split the steel core

If you want the exhaust heat drill a 1/4 hole in the heat riser port


Hmm, price went down, cool
http://www.summitracing.com/parts/FEL-1213S3/
 
I should have taken oics when I had the shaker scoop off - It's a half hour project to get it on & off and could not get back to it Sunday.

I think I'll have the speed shop start with a leakdown test and replace the intake gasket. I suspect that's the culprit.

Thanks to all for the feedback.
 
That's what im thinking mine is too. It runs good, but stayed steady at 5 on my vacuum gauge. And has a big hesitation if I give it throttle quickly.
 
dodge freak said:
Fel Pro print-o-seal with the steel core. It never spilt and can be reused. Just hi tack it to each head and leave the intake side dry. Gasket stays on the heads and I reused them many times doing intake swapping

http://www.summitracing.com/parts/FEL-1213S3/
Click to expand...

Thanks im going to order those too. What do you normally do on the front and rear? Use the gaskets or just use gasket maker? Im kind of thinking the cork ends on it now may have not let it seat completely.
 
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