View Full Version : Knock Knock
04-04-2006, 10:39 AM
After I spent money on heads and some learning too boot, #3 is knocking. Am I better off just getting a crate with a warrenty?
04-04-2006, 11:10 AM
Sounds like a good Idea , that way you have a warranty . Sorry to hear you are having such bad luck. :(
04-04-2006, 04:57 PM
Crate is a good idea, but if everything on top is new.....a new short block might surfice?
04-05-2006, 04:34 PM
Travis--If you are sure it is a rod--if you kill the cylinder the knock should go away--then drop the pan. You know it is a snap to do that. Pull the rod cap and look at it. If it is not too bad you be able to get a caliper in there and check the journal. There is an outside chance you might have caught ist soon enough where a set of undersize bearings might be in order. If not I have a 350 short block that needs to be bored but it has a good crank, fairly new cam and lifters, and a new set of bearings to go with it. Only has about 5000 miles on the rebuild when car got wrecked. You can have it for what I have in it. Later
04-05-2006, 06:33 PM
I thought the pan couldn't be removed on a tri-5 without pulling the motor or linkage???
04-05-2006, 06:42 PM
Travis, I just replaced the pan gasket on my 55. You will need to drop the steering linkage. I took the idler arm loose from the frame and pulled it down.
04-05-2006, 09:24 PM
I'm not sure what's wrong with the motor. I ran it today and no tick. Did start to run rough after warming up.
04-05-2006, 10:14 PM
That makes me think valve train. You may want to pull the valve cover and see if you have a bent push rod, bad rocker and broken valve spring?
04-05-2006, 10:59 PM
I just had it open the other day adjusting valves (same day). Knock was in the block not in the head, used a stethascope.
04-05-2006, 11:04 PM
Humm...well I guess a tear down is in order then. Might be a piston broke. They tend to knock more under a strain though.
04-06-2006, 01:56 PM
I'm not for sure.... I'm not a mechanic ;)
04-06-2006, 05:47 PM
Check a couple more things first.
If you have a torque converter to flywheel bolt loose that will sound like a rod knock , or the fuel pump rod can also sound like a rod knock.
Since you recently had the engine out a torque converter loose bolt could be the noise
04-06-2006, 07:34 PM
I used a stethascope before. I wonder if it's because I haven't ran it in 5 months.
04-06-2006, 09:02 PM
You can use a stethascope and still not be able to tell the difference between a rod knock and a knock comming from a torque converter bolt.
You are sure you did not drop a valve.
04-06-2006, 09:14 PM
did you try tightening the exhaust manifold bolts. Did you try pulling the plug ire and seeing what happens. Hell drive it down to my place--if it makes it you are in good shape--if it doesn't we will know why
04-06-2006, 10:07 PM
My answer is based on experience with the same thing, I thoguht i had a rod knock one time and it was a torque converter bolt.
When you listen to the bottom half of the engine it will sound the same, that is why i said you could not tell the difference.
When I said did you drop a valve, I also had that happen, I floted a lifter and a valve droped down and hit the top of the piston and got stuck thereby casuing a knock that also sounded like it was comming from the bottom end.
04-13-2006, 07:38 AM
I drove it out to my parrents house last night and it started running better. I'm going to be brave today and drive it to work today :)
04-13-2006, 08:57 AM
I made it and it's running better.
04-13-2006, 05:44 PM
Home I go...
04-13-2006, 08:25 PM
I made it home. Traffic on the Poplar Street Bridge was backed up as normal for about 2 miles stop&go. Besides not wanting to idle after stopping and going (generator?) the temp only went to 190 and 160 when moving. I noticed a oil leak, probably cause from rear intake gasket as that was the only wet spot I could feel. I don't think the carb is set up right for this motor, still seems sluggish more so with these 305 heads or since I did the swap. I think I may save up some $ and get a crate 350, just for piece of mind and faster ;)
Ken, I do need to run down there and finially meet you. Maybe you could wake up my little 265 :)
04-13-2006, 11:07 PM
I got another question. I have been trying to set my timing and carb via vac guage. Can it be done this way? It seems to run ok, but still slugish while slowly accelrating. Although I don't have all the faith in my vac guage either, as it's few years old cheapie.
I can't seem to get much vacuum off the port the the vac advance runs from (5"). The other port on my edelbrock carb has about 19".
04-13-2006, 11:17 PM
Switch the vac advance to the hot line (19 inches). Have you set the timing with the vac line off the advance and plugged? You should. Once the base timing is set, reconnect the vac advance. Then hook the vac gauge up and adjust the carb to the highest vac reading.
04-14-2006, 12:08 AM
no timing light, just been setting off the highest vacuum.
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