L48 or GM LM1 which is better?
Thread Starter
Instructor
Joined: Jun 2002
Posts: 127
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From: I like cats
L48 or GM LM1 which is better?
Im trying to decided if i should switch out my L48 for a LM1 but will i be down on power? how do they compare. I hear horror stories from the LM1 but are they really true? thanks in advance.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
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From: Las Vegas - Just stop perpetuating myths please.
Re: L48 or GM LM1 which is better? (1978Vette)
Bought my shark with a clean’ie new LM1 installed – my best guess 30K mi. max.. No major problems but car was a real dog. Puffed blue smoke on startup and had small idle miss. On cam and head swap found #4 exh lobe wiped nearly round and gobs of oil cake on the intake valve stems. Looks like previous engine installer failed to break in the cam/engine correctly. Found the lifter valley clean as a newbe. Don’t know how they ruined the valve seals?
Now what is nice though is everything will bolt right up to a shark and be smog legal. Good reliable new engine for less than cost of a good rebuild. A great price.
Just keep in mind those stock heads will not make good performance heads – chambers too lame and not worth the money/effort to improve.
On a budget it might be fun to experiment with high ratio rockers, steel shim head gasket and even a cam swap before installation. Vortec heads maybe? Umbrella oil seals on the valve stems would be a must do for me.
:seeya
[Modified by cardo0, 1:52 AM 8/14/2003]
Now what is nice though is everything will bolt right up to a shark and be smog legal. Good reliable new engine for less than cost of a good rebuild. A great price.
Just keep in mind those stock heads will not make good performance heads – chambers too lame and not worth the money/effort to improve.
On a budget it might be fun to experiment with high ratio rockers, steel shim head gasket and even a cam swap before installation. Vortec heads maybe? Umbrella oil seals on the valve stems would be a must do for me.
:seeya
[Modified by cardo0, 1:52 AM 8/14/2003]
