Ive swapped a 350 into my car about 1 1/2 years ago and now I have 6000 miles on it. I still have the stock intake and exhaust from the LG4 on it so its not really a hot rod. Back to the story though. Last week I was driving to a friends house and I was coming out of a corner at around 30mph. I gave the car a little gas to accelerate but not enough to get it to drop down a gear and all of a sudden the car started shaking like there were giants on either side rocking it back and forth. Now its running rough and stutters when I am taking off from a stop. Its like its missing but it sounds like all the cylinders are firing when its idling. I can hear a faint steady click from the engine that could be from the valvetrain somewhere.

I have checked for vacuum leaks and couldnt find any and I have also pulled the plug wires to make sure they were all getting spark. The car always bogs down and clicks when I give it too much gas but not enough to downshift but it never did this before. Im going out to pull the plugs and if they are ok Im going to pull the valve covers to check that the valvetrain is functioning properly. I think I may have collapsed a lifter or bent a pushrod or something by the carb throwing too much gas into the enging and 'lugging' it combined with the restrictive exhaust it may have put too much pressure onto the valvetrain and broke something. Its not big deal if it did I will just crack it open and replace the cam/lifters and pushrods. It may have blown the head gasket in between 2 cylinders and that is what is making it feel like its missing but why im still 'hearing' it fire on all 8.

Any other ideas of what it may be? I am hoping that I just fouled a plug so I can get back on the road. If any of you have run into this before and can offer advice I would appreciate it. Is it possible to foul a plug where it will still fire the cylinder but not very well? Ah well Ill find out in a little while.

Thx
Wesdog

 

Hook up a tach, disable the idle speed control, and perform a power balance test by removing one plug wire at a time (insulated spark plug boot pliers are a MUST for this). You should at least be able to isolate the weak/dead cylinder.

 

well the guy who built the engine put the valve covers on the wrong side so after checking the plugs/wires I was going to pull the covers to put them where they go anyway. Right now I have the heater hoses right on top of the oil fill cap on the valve cover. It should be on the other side.

I didnt get to mess with the car at all yet because I have been watching my little one while the sitter has been ill. Ill get on it tomorrow and pull the plugs. I dont think its the wires because they havent been on the manifolds and are in really good shape. I really hope its just the plugs. Im gonna pull them and if they look rough Im going to put some new ones in.

Think hard about it being something easy and maybe it will be.

 

Well I finally got around to working on the car. I pulled the #1 plug and it was nasty looking. As a matter of fact the front 4 cylinders were horrible and black and wet. Then #4 plug was so covered up the gap had been completely filled with buildup (oil/gas/carbon). I also changed the oil and it smelled like pure gas. I guess Im going to pull the valve covers tomorrow and see what it looks like.

After replacing the plugs it ran worse than it did before. Before you ask I did them one at a time so there is no way the wires are on the wrong cylinders. I have a manual and looked over the firing order to ensure it was correct. Not only is it running worse but the noise I was hearing clicking near the top end on the passenger side is a whole lot louder now, and it sounds like something is sucking/pushing air when the car is running. There is no oil in coolant or coolant in the oil, nor is there white smoke from the exhaust. The only thing besides the valvetrain it could be is the head gasket blown between 2 cylinders causing the sucking noise when one is on the compression stroke forcing air into the cylinder next to it. I would guess its between 2 and 4 because they looked worse. The #6 cylinder next to 4 looked almost just right. It was only a little black from running rich. I guess I may have to break down and pull the motor and rebuild it (my damn self this time).

I dont know what to do Im so pissed right now. I have another car to drive but it needs a new control module 160$ before it will start and the tranny is so screwed on it that it wont go anywhere until the car has been running for 20 minutes and the fluid is warm. Otherwise when I put it in gear it just revs up and doesnt go anywhere. HAHA what crappy luck I have with cars.

Oh well if I do rebuild it Im getting it clearanced so I can stroke it and port/polish the heads myself. I just hope I havent broken a ring and torn up the cylinder. I dont feel like hunting for a decent 350 core. I want a 2 bolt so I can put in the splayed 4 bolt just for the extra strength.

Now that I have changed plugs and inspected the wires (good) what do you guys think it could be. I am past the point of hope that its something easy to fix. I really had hoped that it was just some blowby and running rich that had fouled the plugs but it only made things worse. I guess thats what I get for putting in a motor that a guy built me from "What he had lying around his shop".

Take care Ill post an update when I get the valve covers off to inspect the valve train. I think I have now learned that if you want something done right you have to do it yourself.

Wesdog

 

Do a compression test.

Sounds alot like a blown head gasket.

If you get 2 adjacent cylinders with low compression, odds are, it's the head gasket.

 

Well since the #4 cylinder was fouled so bad you couldnt even see the ground electrode or gap because of the oil/gas/whatever built up on it, plus the fact that the guy who built it used standard bore pistons and its bored .040 over and he just used the .040 rings they never set good. I have decided after talking to some friends who heard the car and saw the plugs that I am just going to pull the motor and rebuild it with the right parts.

It was making a hell of a clicking noise after I changed the plugs and started it because of the extra pressure of that cylinder firing again on the valvetrain. I am almost 100% positive that something bad happened to a lifter or pushrod or even the cam. The clicking noise is coming from the 2-4 area and its loud enough to hear over the intake noise and exhaust while sitting in the car. Like I said it also is making a sucking/pushing air noise so head gasket could be part of the problem but I am going to just pull it and rebuild it myself. I need to learn how anyway so nows a good a time as any.

If the block checks out ok after magnafluxing Im thinking of building a stroker and porting/polishing the heads. I am not going to build anything like a 400hp beast or anything as the tranny and rearend are stock and would be eaten alive. I just want a good reliable, strong engine that if some **** burner tries to mess with me I can hand him his ***. I am hoping for around 275-325 hp at the rear wheels. I think a 383 with the heads ported, edlebrock performer rpm intake, edel 600cfm carb and some cheap hedders will get it there. I am looking for 8.3:1 or maybe up to 8.7:1 compression with a cam with an advertised duration of 280 and 1.54 rockers with stock height springs. I may do all of that and just stay 350ci to save money but it will still be better than what I have now. Stupid LG4 exhaust on that 350 probably did it to me more than anything else.

Funny thing is that Im not mad or upset anymore. I am kind of glad that I get to pull the motor and rebuild it. Its something I am interested in and I think I have the time/patience and ability to do it right. I also have friends who know what they are doing and one of them is awesome at porting heads and has offered to do it for me for some beer.

Ill keep you guys updated if you are interested.

-vJ-

 

Oh yeah the rear end is original and the car has 180,000 on it and I dont think anyone has ever changed the fluid in the differential. HAHA I guess I need to do that while I am working on the car. I have some slick 50 synthetic 80W-90 I can use its been sitting in the garage for a couple of years and I dont think its even made anymore. We dont sell it at AutoZone and that is where I got it a few years ago. Probably just get some royal purple or something really good since it has been ignored for so long.

I am waiting a few years until I get the body and interior work done to build the ultimate hot rod with a super motor and built tranny and maybe moser 12 bolt rear end. I am just going to build myself a motor with some power but that will keep me going for 5 or 6 years and maybe 100k miles.

Well Im going to go work on my mother in laws car (thermostat) and then start degreasing my engine and getting it ready to come out.

Later guys
Wesdog