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Hey folks! I've got a 1300 in my 77 spitfire, and I'm getting oil in all 4 cylinders. a little backstory: End of last fall, generally running pretty well. the car sat for a week or so, and when I fired it up, i had a cloud of white fog - head gasket, no biggie. pulled the head, and as expected, coolant leak into cylinders 3 & 4. No mixing of fluids, all bores looked good, but heads needed some cleanup. I decarbed the head and didn't see any obvious issues, then gave the valves a quick lap. everything looked pretty good for an old engine. put it back together with a good head gasket, fired her up and ran good at idle, but gray oily smoke on acceleration. pulled the head and didn't see any issues with the gasket or mating surfaces, so decided it may have just been burning out leftover oil and such from cleaning things up. new gasket, back together, no change... compression check shows 125-135psi. opened her up again, being extra careful of the fluids, and there was about a teaspoon or so of nice clean oil on top of each piston. I verified clear oil passage to the rocker tube and did some extra cleaning on the valve train. just in case, I installed Ford Pinto stem seals on the intake valves and found a considerable amount of oil on top of the intake valves - a nice little puddle inside the chamber. reassembled, fired right up, still no change. considerable gray smoke, increasing with any acceleration beyond idle. So I ordered a digital borescope and bleed-down test setup. after 15-20 minutes of runtime, the borescope showed a puddle of oil in each cylinder. bleed-down test surprised me by showing 10-12% (though the oil in the cylinders made it a "wet" test, no way to do a "dry" run). all runtime after this last gasket was done with valve cover removed. reasonable dribble of oil through the rockers, but nothing around the valves to explain the oil intrusion (no externa oiler involved)... What am I missing? I can make no sense of it.
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Spitfire 74 1300 - I am officially befuddled...
- Thread starter jim-w
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CJD
Yoda
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Have you looked at the PCV valve and system?
Also, 10-12%...is that the amount of bleed or the retained pressure on the bleed down. Either way...that is REALLY poor. Should be closer to 2-5% of pressure loss. SO, when you run the bleed down test, you need to put your ear up to the intake, the exhaust pipe, and the crankcase, to determine whether the leak is intake valve, exhaust valve, or rings. Then you know where to look for the problem.
Also, 10-12%...is that the amount of bleed or the retained pressure on the bleed down. Either way...that is REALLY poor. Should be closer to 2-5% of pressure loss. SO, when you run the bleed down test, you need to put your ear up to the intake, the exhaust pipe, and the crankcase, to determine whether the leak is intake valve, exhaust valve, or rings. Then you know where to look for the problem.
I never thought about the PCV. I must admit total ignorance on PCV setup (though a deep-dive last night does make it clear that it could be my issue) - over the years, I've had many older cars with them and some without, and I have never given them a thought. This car does not have one. I bought it at the end of last summer, drove it for a couple months without obvious problems before the aforementioned head gasket issue. With the DGV and Cannon manifold, I see it will be easy to drill and tap in a vacuum line and add one. I see many people also add an oil separator can. I'll see what I can do this next weekend. Is there a particular type you would recommend? I'm not seeing much by way of "sizes" or "ratings".
On the bleed test, that is the loss. At 50psi, I lost about 4.5 psi, and at 100psi, I lost right about 10 (I double checked my shop notes this morning). Are these cars somehow different from others in this respect? I ask because both the documentation for the tester and considerable searching online indicate that 5-10% loss is quite good, with >15% just starting to imply issues (though not yet necessarily a "problem"). I plan on re-running the test next weekend, as I did not test the engine hot. using a mechanics stethoscope, I heard nothing in the exhaust or intake, and only a little popping and hissing in the case. All cylinders remarkably similar. Thank you for your time and help!
CJD
Yoda
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Even if you do not have a PVC, the crankcase must be ventilated...somehow. If it is not, then the crankcase pressurizes with back-pressure and will overwhelm the rings. That could cause oil in the chambers.
As far as the cylinder bleed-down checks...
A street car will run at 10-15% bleed down, but it is not desirable. Most cars with good valves, head gasket, and rings will be less than 5%. You are right, you could let it slide to 15% bleed, but that is when something needs attention. When you run the test again, listen closely to where the air is going...THAT is as important as the reading. With a tight cylinder you will only hear the hissing at the gage...not anywhere else.
A quick story about PVC...
My first car was a 1967 Camaro with a 350 small block engine, that had a road draft tube for crankcase ventilation. The same as the TR2/3's. I replaced the engine with a crate motor "long block" from GM. I re-used the manifolds and other parts from the '67. The problem was that the crate motor was newer and was designed for a PVC system. I looked at pictures of newer Camaro's, and I drilled holes into the valve covers and ran one hose to a PVC valve and into the intake, and the other from the other valve cover to the air filter. I thought, "great! It is just like the new PVC system!" I drove the car to school (1000 miles), and the next week it started belching smoke out of the exhaust like a mosquito sprayer!! I didn't have any time at school to work on it, so I took it to a shop and told them it was my first engine install, and I likely screwed something up...so look it over closely. They tore down the engine and told me the new rings never seated. They replaced the rings, honed the cylinders, and charged me $500 (which is like $3000 today). A week later the belching fog spraying smoke came back. Back at the shop again, and we were discussing why the rings were not seating...again. While talking to the owner, one of his workers started looking at my valve covers. He noted that I just drilled a hole for the hose fitting, and there was no baffling to prevent the intake from sucking oil from the valve rockers right into the intake manifold!!!
The lesson...if you modify from the factory systems, you better understand what you are doing. The worker had a set of Corvette valve covers...with the oil baffling...which I bought for $20 and fixed the entire ring seating problem. At $500, which took me over a year to pay my father back for the loan, this was a lesson I never forgot!
As far as the cylinder bleed-down checks...
A street car will run at 10-15% bleed down, but it is not desirable. Most cars with good valves, head gasket, and rings will be less than 5%. You are right, you could let it slide to 15% bleed, but that is when something needs attention. When you run the test again, listen closely to where the air is going...THAT is as important as the reading. With a tight cylinder you will only hear the hissing at the gage...not anywhere else.
A quick story about PVC...
My first car was a 1967 Camaro with a 350 small block engine, that had a road draft tube for crankcase ventilation. The same as the TR2/3's. I replaced the engine with a crate motor "long block" from GM. I re-used the manifolds and other parts from the '67. The problem was that the crate motor was newer and was designed for a PVC system. I looked at pictures of newer Camaro's, and I drilled holes into the valve covers and ran one hose to a PVC valve and into the intake, and the other from the other valve cover to the air filter. I thought, "great! It is just like the new PVC system!" I drove the car to school (1000 miles), and the next week it started belching smoke out of the exhaust like a mosquito sprayer!! I didn't have any time at school to work on it, so I took it to a shop and told them it was my first engine install, and I likely screwed something up...so look it over closely. They tore down the engine and told me the new rings never seated. They replaced the rings, honed the cylinders, and charged me $500 (which is like $3000 today). A week later the belching fog spraying smoke came back. Back at the shop again, and we were discussing why the rings were not seating...again. While talking to the owner, one of his workers started looking at my valve covers. He noted that I just drilled a hole for the hose fitting, and there was no baffling to prevent the intake from sucking oil from the valve rockers right into the intake manifold!!!
The lesson...if you modify from the factory systems, you better understand what you are doing. The worker had a set of Corvette valve covers...with the oil baffling...which I bought for $20 and fixed the entire ring seating problem. At $500, which took me over a year to pay my father back for the loan, this was a lesson I never forgot!
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Thanks for that! I am planning on checking for baffling in the valve cover as well this weekend. Everything I have done since the first head gasket change has been done without even venting to the air filter, valve cover barely snugged down (mostly with the valve cover off). car has been on jackstands and ramps all winter. The upside to this is that I have another engine ('75 1500) half torn down and looking to be in beautiful shape, along with all the internals from another 1500 that had a cracked block (neither look to have had much runtime). currently searching for a local shop that won't run screaming from a little Brit engine, lol. The hope was to get a year or two of fun out of the 1300 while I get that one rebuilt. Once i get the spare engine magnafluxed, I can fully commit to that plan. The 1300 has had a good life, currently already been bored .060 over... If I can't get the 1300 happy enough for the season, well, then I guess I change gears and hope for next year! I really appreciate your input on this, as you've given some options to explore.