<gulp> I hadn't thought of that possibility! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

shuttermutt · 11-04-2003, 10:02 PM

Those of you that followed this thread are aware that my 68 is currently down waiting on parts. Anyway, I was talking to my old man this evening and we ran through the symptoms again. He reminded me of a rather nasty possibility... a hole in a piston!

I'm keeping my fingers crossed, but only a compression test will tell for sure. In the mean time, I'm hunting down an HEI unit and a swap-on carb to eliminate those possibilities. Oh, man... that'd be just my luck!

But, that wouldn't explain A) the fact that it threw a very similar fit about a month ago then cleared itself out and B) the off-idle hesitation, would it? That's more like what a pissy carb would do, yeah? Jeez... I hope so!

lukecp · 11-04-2003, 10:06 PM

Didn't you say you have a cold knock?
It could be the problem....fairl unlikley. SBC's (especially 327's) are usually very tough motors...the piston shouldn't break unless the engine was revved overly high......

I think your problems will proably be solved by an HEI, good carb, and a tuneup

shuttermutt · 11-04-2003, 10:22 PM

Cold knock (2-3 seconds on start-up), low power, poor gas mileage, low oil pressure at idle... it's all consistent, but (as far as I know) the engine hasn't been stressed that hard. I think I'm worrying too much. My wife laughs at me. While the truck is down, I'm "forced" to drive my BMW.

**truckster** · 11-04-2003, 11:05 PM

I think you'd notice a lot of blow-by with a hole in the piston. You'd probably have smoke and oil coming out of the motor everywhere.

jamesi20 · 11-04-2003, 11:14 PM

I am concerned more than others about your problem!!! Low oil pressure and cold knock could very possibly be a Main Bearing problem.

Class of 69 · 11-04-2003, 11:38 PM

The knocking, and low oil pressure are either a main, or rod bearing, OR, maybe a cam bearing...the ticking and missing and backfiring thru carb, are flat cam lobe symptoms. I suggest pulling the valve covers, and looking for a very loose rocker arm.

jamesi20 · 11-04-2003, 11:42 PM

i AM INCLINED TO AGREE WITH cLASS OF 69..IT SOUNDS LIKE MORE THAN A CARB OR TUNE-UP PROBLEM.

shuttermutt · 11-04-2003, 11:48 PM

Okay, maybe you guys don't understand the concept of making me feel better about this little problem!

What I want to hear is, "Oh, you forgot to change the <insert cheap part here>!" or "Ha! Just turn the <stupid little bolt> one-quarter of a turn!"

Oh, who am I kidding? I can see the writing on the wall and it spells R-E-B-U-I-L-D!

cableguy0 · 11-04-2003, 11:53 PM

actually you do not have to run a motor hard to put a hole in a piston running it lean will do the same thing. will burn a hole in a piston before you knew what happened

Class of 69 · 11-08-2003, 03:22 PM

Quote:

Originally posted by shuttermutt
Okay, maybe you guys don't understand the concept of making me feel better about this little problem!

We'll be here to help you feel better when it comes time to pick a new cam!!

Can you spell LOPE ??

11-04-2003, 10:02 PM	#1
shuttermutt Don't say "Oops!", Doctor Join Date: Nov 2003 Location: Houston, TX Posts: 677	<gulp> I hadn't thought of that possibility! Those of you that followed this thread are aware that my 68 is currently down waiting on parts. Anyway, I was talking to my old man this evening and we ran through the symptoms again. He reminded me of a rather nasty possibility... a hole in a piston! I'm keeping my fingers crossed, but only a compression test will tell for sure. In the mean time, I'm hunting down an HEI unit and a swap-on carb to eliminate those possibilities. Oh, man... that'd be just my luck! But, that wouldn't explain A) the fact that it threw a very similar fit about a month ago then cleared itself out and B) the off-idle hesitation, would it? That's more like what a pissy carb would do, yeah? Jeez... I hope so! __________________ 'Mutt 1968 CST LWB: R.I.P. 1967 Chevelle: TPI 454 beast 1967 C10 SWB: Claimed when Bumpster didn't put it on his list

11-04-2003, 10:06 PM	#2
lukecp Formerly yellow72custom Join Date: May 2001 Location: Austin, TX Posts: 7,531	Didn't you say you have a cold knock? It could be the problem....fairl unlikley. SBC's (especially 327's) are usually very tough motors...the piston shouldn't break unless the engine was revved overly high...... I think your problems will proably be solved by an HEI, good carb, and a tuneup __________________ '72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride. '70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck. '97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg

11-04-2003, 10:22 PM	#3
shuttermutt Don't say "Oops!", Doctor Join Date: Nov 2003 Location: Houston, TX Posts: 677	Cold knock (2-3 seconds on start-up), low power, poor gas mileage, low oil pressure at idle... it's all consistent, but (as far as I know) the engine hasn't been stressed that hard. I think I'm worrying too much. My wife laughs at me. While the truck is down, I'm "forced" to drive my BMW. __________________ 'Mutt 1968 CST LWB: R.I.P. 1967 Chevelle: TPI 454 beast 1967 C10 SWB: Claimed when Bumpster didn't put it on his list

11-04-2003, 11:05 PM	#4
truckster Senior Member Join Date: Jan 2001 Location: Orem, Utah Posts: 7,976	I think you'd notice a lot of blow-by with a hole in the piston. You'd probably have smoke and oil coming out of the motor everywhere. __________________ I have sworn upon the altar of God, eternal hostility against every form of tyranny over the mind of man. - Thomas Jefferson

11-04-2003, 11:14 PM	#5
jamesi20 Senior Member Join Date: May 2002 Location: NORTHEAST OHIO Posts: 493	Cold Knock,Lo Oil press. I am concerned more than others about your problem!!! Low oil pressure and cold knock could very possibly be a Main Bearing problem.

11-04-2003, 11:38 PM	#6
Class of 69 Registered User Join Date: Mar 2003 Location: Stillwater MN Posts: 1,166	The knocking, and low oil pressure are either a main, or rod bearing, OR, maybe a cam bearing...the ticking and missing and backfiring thru carb, are flat cam lobe symptoms. I suggest pulling the valve covers, and looking for a very loose rocker arm. __________________ 69 GMC K10 ..some restoration required....still..

11-04-2003, 11:42 PM	#7
jamesi20 Senior Member Join Date: May 2002 Location: NORTHEAST OHIO Posts: 493	i AM INCLINED TO AGREE WITH cLASS OF 69..IT SOUNDS LIKE MORE THAN A CARB OR TUNE-UP PROBLEM.

11-04-2003, 11:48 PM	#8
shuttermutt Don't say "Oops!", Doctor Join Date: Nov 2003 Location: Houston, TX Posts: 677	Okay, maybe you guys don't understand the concept of making me feel better about this little problem! What I want to hear is, "Oh, you forgot to change the <insert cheap part here>!" or "Ha! Just turn the <stupid little bolt> one-quarter of a turn!" Oh, who am I kidding? I can see the writing on the wall and it spells R-E-B-U-I-L-D! __________________ 'Mutt 1968 CST LWB: R.I.P. 1967 Chevelle: TPI 454 beast 1967 C10 SWB: Claimed when Bumpster didn't put it on his list

11-04-2003, 11:53 PM	#9
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,948	actually you do not have to run a motor hard to put a hole in a piston running it lean will do the same thing. will burn a hole in a piston before you knew what happened __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

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