New Motor + Hot Running = ?, Advice, help, suggestions? |
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New Motor + Hot Running = ?, Advice, help, suggestions? |
jhadler |
Aug 23 2009, 06:25 PM
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#1
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Long term tinkerer... Group: Members Posts: 1,879 Joined: 7-April 03 From: Lyons, CO Member No.: 529 |
Hey all,
Starting a new thread here... I'd like to get some advice please. Here's the scoop: New motor. 9:1 2056 w/ceramic coated euro race headers. Stock D-jet and stock ignition. Running on Brad Penn break-in oil. Two shake down drives for break-in (varying rpm and load, staying out of WOT and mostly below 4k rpm), and they both have the same basic symptoms. The oil temps get too high and idle turns to cr*p. Drive one: 75 degree ambient, 40 minutes driving. head temps vary between 250-275, never higher than 300. Oil temps climbed to 230, and once hot won't idle worth a damn. - backed off ignition advance to stock, was running at 30 degrees. Capped vacuum retard hose, seemed to idle better without. (mistake?) Drive two: 85 degree ambient, 25 minutes driving. Head temps vary between 250-300, never higher. Oil temp went to 250. Hot idle just plain sucked. I know I need to get a wideband on there to figure out what the mixture is doing, but if the mixture was going lean, I'd expect to see excessive head temps right? Can the oil temp simply be a tight motor on light oil? It doesn't seem right though. Help? Advice? Suggestions? Last thing I want to do is lunch this motor. -Josh2 |
Jake Raby |
Aug 25 2009, 01:57 PM
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#2
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Engine Surgeon Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
WOW!
You only have .016 deck height?? The piston to valve clearance you state is also way too tight on both the intake and exhaust valves. If those clearances are that tight cold, what do you think they are doing hot and fully expanded? With that tight of deck your engine might like as little as 2^* advance, but you'll be colliding pistons to the heads at any kind of revs once the engine is fully expanded.. The least deck I have ever successfully ran was .021 and even then it was knocking the carbon off the chambers and piston tops. |
byndbad914 |
Aug 25 2009, 11:31 PM
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#3
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shoehorn and some butter - it fits Group: Members Posts: 1,547 Joined: 23-January 06 From: Broomfield, CO Member No.: 5,463 Region Association: None |
...The piston to valve clearance you state is also way too tight on both the intake and exhaust valves. If those clearances are that tight cold, what do you think they are doing hot and fully expanded?... snipped that from a post above and he also asked about 0.220 v 0.022 which was a piston to valve #... that is what I was referring too (IMG:style_emoticons/default/smile.gif) It seems to me he like neither the piston to valve nor the deck height. I think piston to valve seems totally reasonable unless I am missing something that is somehow specific to T4s. I know nothing about T4 deck ht specifics. |
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