Guest ntc Posted January 27, 2014 Report Share Posted January 27, 2014 Yes Quote Link to post Share on other sites
ChrisR-4A Posted January 27, 2014 Report Share Posted January 27, 2014 Hi Stef, if the engine is now running fine with no pinking or overheating I would be inclined to leave the head alone and fix the crankcase pressure problem. What you need is a breather pipe from a TR4 which is about 1 inch dia and fits in the hole where the fuel pump was. This pipe does have a dogleg in it to prevent oil finding its way out. Also try replacing the small filter on the rocker cover vent with about 1 meter of 1/2 ins hose to go down past the carbs to just past the chassis. Quote Link to post Share on other sites
peejay4A Posted January 27, 2014 Report Share Posted January 27, 2014 I'd consider doing the above, but the breather snorkel goes into a hole which is below and slightly behind the fuel pump mounting. It will have a plug in it which can be a swine to remove with the engine in the car. Luckily I did mine with the body off. Quote Link to post Share on other sites
MichaelH Posted January 27, 2014 Report Share Posted January 27, 2014 Hi : You need a standard triumph crank case vent as in photo ! shows where it goes - below the fuel pump- mine is slightly altered to go into a oil catch tank Photo2/3 show the vent in it's original form note it is about an inch id and a smaller tube is not enough as the persistent pressure will blow oil out all over the engine Regards Michael 1. 2. 3. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted January 27, 2014 Report Share Posted January 27, 2014 Thanks all - especially Mick- for your comprehensive explanations and advices. The head is back from the machine shop and the cracks have gone after the 1st shaving of 10 thou. Push rod tubes have been replaced (except one which they screwed up on assembly - BTW ordered from RB and needed to be re-machined to fit in). Now I'm going to sharpen the edges of the waterways, smoothen the edges of the compression chambers and put some Loctite around the flare of the tubes just to be on the safe side. Re protrusion issue, I like to drive my 4A a little bit. After reading the comments I believe that the issue has ballooned. It's just a solid and reliable tractor engine which could go on for ages with minimum maintenance. IMO If the constructor gives a .002 tolerance that's to allow the head gasket to mitigate the variations under load and correcting these variations around the same liner as well, otherwise no point having a gasket. So a thorough cleanup of the face of the block and liners, a good copper gasket, a good dose of Locite and proper progressive torque should do the trick for now and until the full engine strip scheduled for her 50th birthday. Let's see how it goes. If the crack cyl 1- which I suspect relates to liner 1 high protrusion- comes back or other leaks appear, that would prove me wrong. Will keep you posted. I need more info I think ... Does the splendidly shaved head look to anyone else that the inlet valve shroud has been removed ? Does the removal of the shroud not cause the head gasket edge to burn as it is sticking into the combustion chamber or worse still the thin edge left glows and causes pre ignition. I was told to leave it 0.020" (about 1/2 mm to you Continental types) thick or completely remove and reshape the liner top corner and steel head gasket to suit. On the point of crankcase venting I agree. Pipe over the side from the rocker cover plus the sidescreen car crank vent - have fun pulling the blanking plug out the block side. It is almost easy on a Micho car as the engine bay is so wide compared to a sidescreen. Resist banging it in any deeper in your frustration though. Removal has been covered in this forum before. Cheers Peter Quote Link to post Share on other sites
Geko Posted January 27, 2014 Author Report Share Posted January 27, 2014 I need more info I think ... Does the splendidly shaved head look to anyone else that the inlet valve shroud has been removed ? Does the removal of the shroud not cause the head gasket edge to burn as it is sticking into the combustion chamber or worse still the thin edge left glows and causes pre ignition. I was told to leave it 0.020" (about 1/2 mm to you Continental types) thick or completely remove and reshape the liner top corner and steel head gasket to suit. On the point of crankcase venting I agree. Pipe over the side from the rocker cover plus the sidescreen car crank vent - have fun pulling the blanking plug out the block side. It is almost easy on a Micho car as the engine bay is so wide compared to a sidescreen. Resist banging it in any deeper in your frustration though. Removal has been covered in this forum before. Cheers Peter Peter, I did smoothen the edges of the combustion chambers and of the gasket rings before assembly. Fact is that both liners bore and gasket rings are 87 mm so it's anyone guess as to whether it will stick into the combustion chambers under load. Old gasket did no show any burns on the rings though. I've just read about removing the blanking plug and I will stick to the fuel pump blanking plate for now. Quote Link to post Share on other sites
Geko Posted January 28, 2014 Author Report Share Posted January 28, 2014 Much better...With a pipe 28 mm inner dia the beast is breathing again with no oil spitting out the dipstick hole at idle and reasonable pressure in the rocker cover. Will keep thinking about a vacuum system not connected to the carb depression. Thanks for the good tips and advices, as usual S Quote Link to post Share on other sites
MichaelH Posted January 28, 2014 Report Share Posted January 28, 2014 Doesn't take you long to get it fixed: looks like a neat solution Regards Michael Quote Link to post Share on other sites
Guest ntc Posted January 28, 2014 Report Share Posted January 28, 2014 Your getting there but more to do Quote Link to post Share on other sites
Geko Posted January 28, 2014 Author Report Share Posted January 28, 2014 Your getting there but more to do he, stay on the lookout, i'll keep you on your toes Quote Link to post Share on other sites
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