Crap! Engine problems.... please help!
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Teching In
Joined: Sep 2006
Posts: 19
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Crap! Engine problems.... please help! OK, just finished putting the new 403ci LS2(ex 382 LS1) shortblock back together, broke it in nice and easy for about 400 miles and changed the oil, and tonight went to the track. 1st time ever since I've owned it, put the MT D/Rs at 18psi, did a burnout, footbraked to about 1600 and punched it on 2, got a couple inches of air under the tires, 1.501 60', and a 4.47 330', then for some reason it didn't shift to 3rd at 6300, and fell off. I coasted the rest of the way down, and when I pulled back into the pits it was running a little rough and every couple seconds get a "clack clack clack", then kinda quiet, then loud again. I had it idling and watching the oil pressure, about 25psi hot, and then "ckkkkk" it stopped running. I tapped the starter and it's not rotating. CRAP! I think it's gotta be in the valvetrain, Superior Automotive had built the heads with Comp beehives and 1.85 rockers on a Comp XE-R grind with .647/.651 lift, I think those idiots facked up the heads too, as the short block they built before was total monkeyshit. I've seen most of the LS1 cams recommend NOT to use 1.85s, but supposedly they had it together and dynoed it up to 6500.... any questions? This is too expensive to keep facking it up, so should I just go back to 1.7s and get a higher lift cam, or find somebody with lobes that aren't going schizo with 1.85 rockers? Oh, and I have to ask...what's a 4.47 330' work out to in the 1/4? :-D
Staging Lane
Joined: Jun 2006
Posts: 68
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Originally Posted by streetwarrior
OK, just finished putting the new 403ci LS2(ex 382 LS1) shortblock back together, broke it in nice and easy for about 400 miles and changed the oil, and tonight went to the track. 1st time ever since I've owned it, put the MT D/Rs at 18psi, did a burnout, footbraked to about 1600 and punched it on 2, got a couple inches of air under the tires, 1.501 60', and a 4.47 330', then for some reason it didn't shift to 3rd at 6300, and fell off. I coasted the rest of the way down, and when I pulled back into the pits it was running a little rough and every couple seconds get a "clack clack clack", then kinda quiet, then loud again. I had it idling and watching the oil pressure, about 25psi hot, and then "ckkkkk" it stopped running. I tapped the starter and it's not rotating. CRAP! I think it's gotta be in the valvetrain, Superior Automotive had built the heads with Comp beehives and 1.85 rockers on a Comp XE-R grind with .647/.651 lift, I think those idiots facked up the heads too, as the short block they built before was total monkeyshit. I've seen most of the LS1 cams recommend NOT to use 1.85s, but supposedly they had it together and dynoed it up to 6500.... any questions? This is too expensive to keep facking it up, so should I just go back to 1.7s and get a higher lift cam, or find somebody with lobes that aren't going schizo with 1.85 rockers? Oh, and I have to ask...what's a 4.47 330' work out to in the 1/4? :-D
sounds like the lift is too high for the springs. And the xe-r lobes are very agressive in their cilmb rate, and will not work with more than 1.7 s, basic knowledge with xe-r cams. It just eats the valve train in seconds. I really dont hope that you have a major brakedown, but it doesent really sound like it. But you need some repair thats for sure.
DoC
Could be a broken spring or two. Might have damaged the valves and or pistons as well if the single springs failed. That valvetrain seems all mismatched. I don't like any rocker over 1.7. Should go with the stocker 1.7 with a .615 lift and some psi, prc or patriot double spring combo. Those are more proven valvetrain combos that work. Are you local in la? If you are and need a hand pm me.
On The Tree
Joined: Apr 2005
Posts: 106
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From: the South
Jeez.................If the heads really have Comp beehive (single) springs and not some high quality double springs that's bad enough with a cam that size but when combined with the added stressing due to the increased ratio rockers (1.85's) well.......I say it would be risky reving it over 3k.........
