EuroDat Posted May 21, 2015 Share #13 Posted May 21, 2015 You are going to have problems with your leak down test as well. Normally the engine is in the car and you can lock the piston at the top but putting it in 4th gear and hand brake on.On the stand it will push the pistion down to the bottom of its stroke unless you can stop the crankshaft spinning. If the piston travels to the bottom a inlet or exhaust valve will start to open and the leak test wil fail.Your idea with the spare tyre for a tank will do. You may need to refill per 2 cylinders.Another thing that could be causing the possible leak is turning by hand is too slow and the pressure doesn't build up enough to force the rings out against the cylinder walls and create a better seal.Chas Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470204 Share on other sites More sharing options...
rossiz Posted May 21, 2015 Share #14 Posted May 21, 2015 oh... i TOTALLY want to see a running engine in the living room video! bolt it to some wood blocks, exhaust would be just the manifold and y-pipe, flames out the back, jerry can of gas up on a nearby table w/fuel line zip-tied to the handle... AWESOME! be sure to open the windows, eh? Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470205 Share on other sites More sharing options...
beermanpete Posted May 21, 2015 Share #15 Posted May 21, 2015 Turning the engine by hand will not tell you much about ring seal. The air leaks past the rings too fast to get a usefull pressure reading at that speed. A leakdown test is better but if the piston goes to the bottom it can be misleading since the bore is not worn much at the bottom. You might be just as well off to install the engine and run it. It seems the question is: Would you rather install a tired motor only to take it out again or tear down a good one only to find out it is ok? 1 Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470207 Share on other sites More sharing options...
rossiz Posted May 21, 2015 Share #16 Posted May 21, 2015 ok, a more serious reply: since the engine is already out and on a stand and drained with the pan off, you're really only a few bolts from a re-ring anyway. a set of rings is cheap, and at 130K miles (i'd assume the odo had rolled) the bores should be fine - you can check 'em with a scope if you want with a scope. i'm guessing you'll still see the hatching. Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470220 Share on other sites More sharing options...
John Coffey Posted May 21, 2015 Share #17 Posted May 21, 2015 Just put it in the car and run it. You're sending way too much time inventing things to worry about. Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470223 Share on other sites More sharing options...
HuD 91gt Posted May 21, 2015 Author Share #18 Posted May 21, 2015 John, that reply made me laugh. Paranoid? Probably. Inexperienced? Oh yes. Know enough to be dangerous? Absolutely.Rossiz/Beermanpete, you make a valid points. It's on the stand. Here comes the inexperience part again. Reringing a block would have to be done with the head off correct (Can't do it from below?). Should have purchased the rebuild book at the same time as the modify one. I bought the engine knowing very little and was prepared to throw it in and see. What is the worst thing that could happen? Spend another day putting the other one in again? Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470226 Share on other sites More sharing options...
beermanpete Posted May 22, 2015 Share #19 Posted May 22, 2015 Yes, replacing the rings requires removing the head. Do you have the necessary tools to properly replace the rings and do all the other work that comes along with that? If not, just run it and see what happens. It seems you have already verified the engine turns and does not have a broken rod or other serious malady. The worst outcome is the realization it is a bit tired. May people on this forum and others, me included, have bought used engines with little to no knowledge about the condition or history and ended up with a good engine. Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470260 Share on other sites More sharing options...
siteunseen Posted May 22, 2015 Share #20 Posted May 22, 2015 (edited) He's gotta remove the head anyway, E31 currently, N47 on the indoor motor. These make it easier, $13 at amazon.com. EDIT: I just read where you're going to use the N47 head. I'm probably wrong but won't the fuel injector holes have to be welded over for carbs? and the exhaust ports are different. Edited May 22, 2015 by siteunseen Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470262 Share on other sites More sharing options...
HuD 91gt Posted May 22, 2015 Author Share #21 Posted May 22, 2015 I have no tools nor experience to change the rings. I would be going straight to the books.The N47 head is on the F54 block already. It has the stud holes for the SU intake manifold. They will mount right up. No infection holes to fill as those are in the injected manifold which I'm not using. The only thing I need is to run an electric fuel pump as it has no cutout for the mechanical pump.As we sit, I'm leaning towards just swapping it in. Thanks for the help, I will keep everyone updated on how it goes. 1 Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470272 Share on other sites More sharing options...
siteunseen Posted May 22, 2015 Share #22 Posted May 22, 2015 I apologize, I should have said "cut outs". Here's a E head manifold gasket on an N47 head. Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470274 Share on other sites More sharing options...
HuD 91gt Posted May 22, 2015 Author Share #23 Posted May 22, 2015 I see what you mean. Hope it doesn't affect performance too much. Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470296 Share on other sites More sharing options...
siteunseen Posted May 22, 2015 Share #24 Posted May 22, 2015 I don't think so. I've been reading too much "how to modify".Sorry. Link to comment https://www.classiczcars.com/topic/51522-turning-engine-by-hand/?page=2#findComment-470298 Share on other sites More sharing options...
motorman7
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