Yikes!!! 305E V6 knocking like crazy!

[TJ's GMC]

Well gents,
Did a compression test and all cylinders are within 105-115 pounds so everything seems ok there. The engine keeps dropping cylinders once in awhile and I'm sure its from the blown head gasket or if both are blown and I don't know it. lol The one leaking currently is getting worse so I haven't been running the engine. Will be getting new head gaskets from summit racing as well as some intake gaskets and a carb kit(not necessarily from them lol). Then I might even take the heads to my machinist and have him look them over to make sure everything is ok and she should be up and running like new. I may even pull the engine to clean it up and repaint it and throw a new clutch in since this one is crap.

[TJ's GMC]

New head gaskets and intake manifold gaskets are on there way. Gonna get a carb kit soon as well. Should have this ol thing running like new soon.

[TJ's GMC]

Head gaskets on back order. sniff sniff

[massey478]

I just happened to view these old posts. I wanted to say how it is most important to use high pressure air to blow out crud around spark plugs before removing them, especially on the V-6 engines we are using. I blow the cavity around the plugs out twice around the engine because stuff from around one plug can fly over to settle around one just blown out. I then loosen the plugs about one turn and repeat the blow-out procedure before completely removing them. It is so easy for crud to settle around the plugs and then if not blown out goes down into the cylinder when the plug is removed. The least it will do is score your cylinder wall. The worst is if it is a piece of some kind of crud that settles on the piston top, maybe sticking there, it causes a knock. It may eventually come loose and it may not. Worst case it might dent or break down the top ring land on the piston then you have a major problem, broken ring, scored cylinder wall. Also check the plug sealing ring seating area in the head for crud. You do not want crud getting between the plug sealing ring and the head, causing it to not seal properly. To clean them I put a bit of grease on the end of a flat blade screwdriver and go around the machined seat carefully with the screwdriver end, the grease captures the bits and keeps them from going down into the cylinder. I-6 engines were bad about inhaling a carb air cleaner mount retaining screw on the carb top that vibrated loose or other trash that might get unnoticed into the air cleaner when changing it. Instant knock! I have seen the screws pressed into the piston top virtually permanently. Head off, new piston, hopefully no cracked head or scored cylinder.

[Ed Snyder]

Originally Posted by massey478

I-6 engines were bad about inhaling a carb air cleaner mount retaining screw on the carb top that vibrated loose or other trash that might get unnoticed into the air cleaner when changing it. Instant knock! I have seen the screws pressed into the piston top virtually permanently. Head off, new piston, hopefully no cracked head or scored cylinder.

I know from painful experience exactly what Marti is talking about here. The original 305D in my '62 Suburban somehow inhaled the threaded rod holding the air cleaner lid down. Instant loud knocking followed by loss of power and big clouds of oil smoke out the exhaust. Head removal revealed the smashed threaded rod and a piston broken in half. That incident led to the installation of the 401M.

[massey478]

Hi Ed, good to be sharing posts with you again! The reason I made all of the adapters to put a 478 in my 1100 Massey was that whoever rebuild the original inline 6 had made the mistake of putting the exhaust springs on the intake valves and vice-versa. Resulted in the head coming off an exhaust valve right in the middle of the busy field season. It had scored the cylinder, broke down the side of the piston, and bent the rod. The motor was a Waukesha, so parts were not cheap. Regardless of the scoring, I put in a new piston, rod, and bearing, re-did the head during a rainy spell so I could at least use the tractor. I had the expected blow-by. I ran it a couple of years that way until it finally got so bad on oil that I dedicated a winter in the shop machining and welding the adapters necessary to put the 478 in it. It proved out well, power went from 93 HP to 205 HP. Traction is the biggest limitation now, but I leave it weighted as it was and just run a gear or two higher as conditions allow. I was told it would be a gas hog but I firmly believe a big motor loafing along will do better than a smaller motor winding up and working hard. Longer life, less fuel for the same work. I also modify the carburetors a bit. In my opinion GM ran these motors way too lean. We had customers complain about mileage; we would open up the main jets a bit and stretch the power valve spring a bit and their fuel mileage went up, engine temp came down. I learned to love these motors from experiences with them! One customer had a tri-axle dump with a 401, called in to the shop he had a miss and that he was on the way to get it fixed from about 20 miles out. To our great surprise we, expecting an ignition problem, found it had pitched the beam of a rod out the side, left the big end on the crank, hung the piston at top. It survived the 20 mile trip that way, idled with just a miss! We had a warranty 401 block that the GM rep had given us permission to scrap. The scrapper guy, when told the block had to be damaged obviously beyond use by anyone, said he usually just broke out the main webs with a sledge. He found he could not do it on the 401. I had to take a welder and carbon cutting rod to cut into the block several places to destroy it per the GM directive.

[Motiv8]

Mr Massey 478. Been a long time since I've seen anybody that knew the correct procedure for removing a plug. That's the way I was taught 70 yrs ago. Been a pro mech and Special eng builder now for 65 yrs. Still building. I'll add one other step. Just loosening the plug will shed a thin layer of carbon. Loosen plug a turn or two, do the full blow away as you posted, tighten plugs , then go drive it. This will almost always blow out that bit of carbon. Very important prior to making a compression test. Most flathead engs of the past had plug recesses that collected grit. Add to that the older engs always had a carbon layer. That carbon could easily stick on a valve seat and your comp test would fool you. Combined w/ wide seats or weak springs, a bit more testing might be needed. Much confusion and unneeded repairs can be avoided following your post #34 and this "drive it " tip. Other things like throttle and choke plate screws not restaked can be found lodged in piston crowns. David

[massey478]

Thank you, David! A good added step to remove carbon in the combustion chamber loosened when plug was turned. Especially true on engines that burn some oil. I had carbon get under a valve for a short time on a Cessna 150 I had changed the plugs on. A good run-up to full throttle cleared it fortunately. I have a 44 Massey Harris tractor that many years ago when plowing started making a knocking noise. Would not turn over after shut off. Motor was locked up. Of course a bearing(s) was expected as the cause but no problem found there. Head removal, very hard to break loose after the bolts were out, revealed a large piece of carbon had broken loose and got trapped between the piston and cylinder head, sticking the piston to the head when it stopped at TDC on that cylinder. Weird, but true! Made good Super Glue! Culprit for the carbon was again a worn engine doing light work during the winter, choke out starting and until warmed up, building up carbon then when spring plowing with the characteristic hard pulling involved happened it caused the carbon deposited from the light work to burn/ break loose. We always saw a good many sparks out the stacks on tractors when running at night until it cleaned up. Engines need to be worked once in a while to keep the carbon under control. I have been down the throttle plate/choke plate screw path several times also. Good thing most are brass!

[POWERSTROKE]

MASSEY478 - A 478 V-6 would make a great tractor engine. I always thought a 305 or 351 in a Farmall M would be a great combination. I grew up on a Midwest grain & livestock farm. Not near enough acres to feed the 500 to 800 head of market hogs every year. All the corn was picked on the ear and ground for cattle feed for the 35-40 head of beef cattle every year and we made three cuttings of alfalfa hay on 20 acres and farrowed the hogs on another 20 acres of alfalfa. Dad wasn't big on farming late into the night and most tractors didn't have working lights, 10-12 hour days was enough but one spring so we could finish plowing we worked till about 10 PM moving hog houses from last years hog pasture to the new one. Farmall H had none too much power for that task, from idling around half throttle no load and cold all winter it was burning up and loosening lots of carbon in the cylinders. At full load those glowing carbon chunks would go 15-20 feet in the air and then fall to the ground, finally stopping glowing just before they hit the ground.

All engines do it, just tractors with vertical exhausts/mufflers just a couple feet ahead of your face make it easy to see.

A guy on the Red Power Magazine forum is putting a 305 V-6 in an M. Been working on it over a year. I hope he posts pictures soon.

[massey478]

Thanks for the comments, Powerstroke! Oh how I remember all of those long days you speak of! Another fellow on Red Power put a 702 V-12 in a TD18. I sent him a Rockford hand clutch assembly off one of my irrigation pump 702's to use on it in trade for his transmission, clutch assy, etc. off the truck he took the motor out of. He is in the cold Canadian north. He runs 'cat trains' with the cats hauling supplies over frozen lakes to remote settlements and dwellings in the winter, pulling sledges. He trails a long cable behind because sometimes things go submerged and the cable allows recovery. To read of his experiences I do not know how he endures all of it. If I remember right he has one of the old Lombard type engines that had a gas motor used for logging also. I do not know if he is still at it. I would favor the Massey Harris 44 or 55 for a power-up because they use all Timken bearings in their transmissions and finals. IHC uses ball bearings. I have seen the nose broken off the mainshaft in M's because low gear puts all of the stress on it. They were famous for shelling out the inner rear axle ball bearing, then there was not enough room between the bull gear and the housing so loose ***** would get between bull gear teeth and push out the bottom of the case. In their defense, this was usually the result of low oil level in the case. The angle of having one wheel in the furrow starved the upside bearing so it failed then the ***** went over under the low side gear and cracked the case. Lots of IHC's did a lot of faithful work, so not meaning to dis them.