LM7 rebuild
Thread Starter
Teching In
Joined: Mar 2012
Posts: 4
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From: Scottsbluff, NE
LM7 rebuild Ok, i am really a noob on the Ls based engines. picked up a lm7 to put in my 68 camaro, was just going to do cam swap and carb conversion and drop it in. Well, had to pull heads to put in new lifters, decided to have heads rebuilt while i had them off, needed to put different springs on anyway, started looking/reading about piston slap issues with these motors. Long story short, i can rock the pistons back and forth (top to bottom) in the cylinders...looks like i will rebuild the bottom end while i am at it. Want to do it right and only do it once.
Has anyone used the sealed power pistons in one of these?
Thanks,
Scott
Has anyone used the sealed power pistons in one of these?
Thanks,
Scott
I also am building an LM7 and am using the Sealed Power .030 over 4.8L flat tops . They are $180 4 all 8 from Summit . The only thing that was a small issue was the compression height . The factory 5.3L 9cc dished 1's came out of the hole roughly .010-.015" . And I took block deck down .005" and the flat tops are exactly .000" flush so I'm going to take another .023" off the block so that with the stock graphite head gaskets I'll have .035" of quench which is about the best quench You can achieve without risking pth (piston to head) issues . I'm also tailoring the combustion chamber volume to end up with 10.5/1 compression . I'm putting a new 28.5 / 18.5 / 1.325 truck radiator in My El Camino which will require a little modification of the frame to fit but will help with pre-ignition . Make sure You either have the rods big ends honed .002" and get the clevites or the Federal Mogule bearings that are .002" larger outer diameter . Federal Mogule makes those bearings in all the common undersizes and different quality levels (stock, race,,,,,,etc) Buy a new O-ring for the oil pump pick-up tube and either port the stock oil pump or buy a new 1 . The factory oil pumps pressure drops off above 6500rpm's at least according to a thread in this forum about a year ago . If You have any more questions don't hesitate to either message Me or just post in this thread . Good luck
I may buy the cometic gaskets 4 the LS1 which are .041" I believe which would then require only .006" more to come off My block deck ,,,,,,,,we'll see They are kind of pricey .
