Fleetwood Meadow Posted June 21, 2018 Posted June 21, 2018 So my compression has finally gotten too bad and I think it’s time to rebuild the engine in my ‘51 Meadowbrook. The cylinders are between 89 and 94. I’m using a lot of oil too. So how in depth does this rebuild have to be? Can I just replace the rings and the gaskets and call it a day? Everything runs very well and I see no metal in the oil changes. The oil pressure stays in the correct pressure. These engines seem to be tanks, you can’t stop them.
Ben Bruce aka First Born Posted June 21, 2018 Posted June 21, 2018 Medd448, you will probably get several different answers. So let me jump in and be first. That is a fairly easy engine to work on. Back when these were just used cars I would drop the pan, pull the pistons and check clearances and wear. Chances were [ARE] good a set of bearings and rings were all it needed. Look at the valves and if none are burned, leave them alone. Perhaps lap them in if concerned. Probably run another 60,000 miles or more. Ben 1
Grimy Posted June 21, 2018 Posted June 21, 2018 89-94 is pretty even, so the car should idle well, and that compression is not too terrible given the compression ratio. As far as oil consumption goes, how much are you using? Many of these MoPaR flatheads will burn off the first quart of oil quickly, and then consume oil at a much slower rate. Let it drop the first quart, then watch the oil level fairly closely. Beyond that, a quart of Marvel Mystery Oil in your crankcase oil will help un-gum rings (I think you said the car had been sitting quite awhile). Next oil change, drain the oil HOT, after a minimum of a 45-minute run. On these engines, I'd consider 400-500 miles per quart, after the first one, perfectly acceptable. And DRIVE it! Enjoy it as it is for the rest of this driving season, and take care of the small incremental improvements they all need while enjoying the car. I don't recall if you've addressed the cooling system and brakes yet; those would be my first priority. I recommend you defer judgment on an engine overhaul until the end of the driving season at least, and perhaps until a year after that.
Fleetwood Meadow Posted June 21, 2018 Author Posted June 21, 2018 I have straightened out the brakes and overheating. Well, the brakes hold pressure and don’t drag although I do need an alignment because it always pulls to the right. As for the consumption.. I can’t say it’s always because this was the first time but I have driven about 150 miles and put in 4 quarts of oil.... Whenever I travel about 50 for more than a mile or so I lose oil like crazy. When I decelerate it smokes. Could increasing the viscosity oil help that? I have been using a 30 weight lately. As far as I know the engine has never been rebuilt. It isles like a dream and it drives without problem. I figured I would bring this up and get some advice from more knowledgeable people so I don’t hurt the engine. This car has been my baby for 5 years. Before me the car hadn’t been on the road since 1973 and the owner before me wanted to rat rod it. I like it as a stock car that I can take the family out and about in.
Grimy Posted June 21, 2018 Posted June 21, 2018 Yes, that's definitely excessive oil consumption and you're due for a ring job--but most likely will have to do quite a bit more "as long as you're in there." I still think the overhaul would be a good winter project and you should give the rings a chance to get freed up. They've probably lost their tension from that 45-year rest. I'd continue to use 30 weight, but would buy it in gallon jugs... Does the car pull to one side when the brakes are NOT applied? If so, an alignment is in order. If the pulling happens during braking, no need another go at brake adjustment.
Grimy Posted June 21, 2018 Posted June 21, 2018 Afterthought: Have you cleaned out the oil filler cap in kerosene? Checked the road draft tube (if any) for being plugged?
Fleetwood Meadow Posted June 21, 2018 Author Posted June 21, 2018 The car pulls to the right even when the brakes are not applied so I’m sure it needs an alignment. I’ve been driving it for the past 5 years. I haven’t tried to clean the oil breather yet but I think I did when I first got it on the road. It’s probably due for a cleaning again. I suspect that I have a leak from the valve cover that’s under the intake. I can’t see it very well because it’s directly under the intake manifold. I stuck my phone down there and blindly took this picture.
Bud Tierney Posted June 21, 2018 Posted June 21, 2018 By all mean pursue that oil leak---supposedly burning a quart every 40 miles or so should belch out clouds of smoke.as well as foul some of he plugs, if not all... Plus, as mentioned, you may've been replacing that first quart that some of these engines habitually blow out of he engine Look under it for evidence of oil blown/leaked out of engine, back on trans, underbelly. Does it drip where parked??? Undoubtedly it's burning some; if you do rings it's considered good form to do bearings. The theory here is that if rings worn , engine has enough miles to have some bearing wear, no problem as reduced compression lessens strain on bearings---BUT, beef up compression with new rings, that extra power is beating on worn bearings, not good. And (sigh) as mentioned above, while it's apart you might as well do the valves, or at least check them, ----that's always the quandary: how much to do when its apart, considering proposed use, financials etc... 1
JACK M Posted June 21, 2018 Posted June 21, 2018 26 minutes ago, Medd448 said: The car pulls to the right even when the brakes are not applied so I’m sure it needs an alignment. I’ve been driving it for the past 5 years. I haven’t tried to clean the oil breather yet but I think I did when I first got it on the road. It’s probably due for a cleaning again. I suspect that I have a leak from the valve cover that’s under the intake. I can’t see it very well because it’s directly under the intake manifold. I stuck my phone down there and blindly took this picture. That pulling could be tires or even something as simple as air pressure.
Rusty_OToole Posted June 21, 2018 Posted June 21, 2018 How bad is the oil burning? How many miles have you put on it since you put it back in commission? How many miles on the engine? You may just need a few long drives to get things working again. Some Marvel Mystery Oil in the gas and in the crankcase, and a few long drives of at least 100 miles may free up the rings. If your oil pressure is good and your compression is decent then you may just need a ring and valve job. Hone cylinders, replace rings, grind or lap valves, good to go for another 30,000 or 40,000 miles.
Grimy Posted June 21, 2018 Posted June 21, 2018 Medd448. your second photo in post #7 above appears to show the fastening of the cylindrical road draft tube to the engine. Disconnect and remove the road draft tube (there may well be a bracket attaching to an oil pan bolt), and clean it out. Look at the chamber where it attaches and see if there is some copper mesh which prevents liquid oil from being thrown out; if so that needs to be cleaned too. This car is well before sealed crankcases and positive crankcase ventilation. Air enters the crankcase through the oil fill cap and exhausts through the road draft tube to prevent a buildup of pressure in the crankcase. If air cannot flow in and out freely, the pressure in the crankcase from normal engine operation will force oil out through any possible escape point, past gaskets. You may need to remove the sheet metal valve covers AKA side pans to gain access to any mesh or diverter inside the crankcase--a little hard to do with the manifolds on. You may find access easier by removing the right front wheel (car on jackstand(s)) and then removing the inside fender sheet metal. You'll have to do that for a valve job anyway.
D Yaros Posted June 22, 2018 Posted June 22, 2018 (edited) If you are going to do the rings, while in there, you should also do the bearings and replace the rear seal on the crank. You do not want to have to go back into the engine to do these things 6 months from now! Edited June 22, 2018 by D Yaros (see edit history) 1
Fleetwood Meadow Posted June 28, 2018 Author Posted June 28, 2018 I have cleaned the draft tube and oil breather. It didn’t look dirty but I was surprised to see the stuff that came out of the mesh opening. I had heard from someone that they had a similar issue where the oil passages were clogged so I got sea foam and put it in the oil as it suggested. So far I haven’t seen much in terms of oil consumption and it may be coincidence but the smoke seems to have lessened.
Fleetwood Meadow Posted June 28, 2018 Author Posted June 28, 2018 Every time something gets fixed another thing breaks, but that’s the “joy” they say. I had the wrong carburetor on the car since I bought it. So I got the right one and just rebuilt it. While I was testing it and revving the engine I saw the radiator hose collapse. So I finished testing the carburetor and turned the car off. That’s when I saw the steam coming from the engine bay. I looked and saw that I had blown out a freeze plug. So now I have to fix that before I can road test the car. I’ll clean the block out a little while the plug is out.
Guest Posted June 29, 2018 Posted June 29, 2018 If it were my engine I would replace all the "core" plugs. If one has rusted through they are all just about the same. Always keep antifreeze or at least water with rust inhibitor in your engine and radiator.
Fleetwood Meadow Posted June 29, 2018 Author Posted June 29, 2018 I took some time and flushed the engine through the hole. I know it didn’t completely clean it but at least it cleaned it a little more than it was. And I found a channel in the block that was blocked so I’m excited about the idea of it running cooler.
Dave Henderson Posted July 9, 2018 Posted July 9, 2018 Before removing the pistons ream the ridge at the top, but be careful to not cut into the piston travel area. Reaming needs to be done any way, and makes removal easier. If not done, new unworn rings could strike the ridge and damage the pistons.
c49er Posted July 10, 2018 Posted July 10, 2018 (edited) You better check for cylinder taper. If the cylinders have too much taper... over .010" the rings still won't be able to stop excessive oil consumption. You need to also check the piston ring lands for damage and wear too. Edited July 10, 2018 by c49er (see edit history)
Fleetwood Meadow Posted July 10, 2018 Author Posted July 10, 2018 I added sea foam to the oil about a week ago and cleaned off the engine when the freeze plug broke free. The leakage has seemed to stop, or at least slow way down. I had seen on a Dodge forum that I posted on that a guy had a similar problem with oil leakage. He said that there was an oil delivery port that was clogged and creating pressure. Once he cleaned it the leakage stopped. That’s what prompted me to try the sea foam. So far it seems to be better. I added a quart of oil because I was almost at the add line. Now I’ll see how long it takes for me to lose that quart.
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