Camshaft question
Thread Starter
Joined: Feb 2015
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From: Conroe, Texas
Camshaft question I have a 5.3 with 862's that I'm installing in a 2005 Tahoe 4x4. The 5.3 in the truck has 706 heads and I know these are identical to the 862's but I'm concerned about the camshafts between the engines. All the camshafts in the 5.3's had the same duration and lift and an LSA of 114° except that the 99's had 115.5° LSA. My question is will there be any issues with how the engine performs if by chance the camshaft in the replacement engine has the wider LSA? I can swap the cams of course but figured I'd ask first.. Thanks!
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Probably not...
The one with the wider LSA will idle slightly better, have slightly lower peak torque, and carry the torque to a little higher RPM. Probably not even a 2% difference in any of those things. The one with the narrower LSA will make slightly more torque but will tend slightly more to ping (might need a slightly less aggressive timing curve); again, emphasis on "slightly". VERY slightly.
I doubt anybody will even know the difference actually, even on a dyno; the difference is within normal variation between motors anyway.
The one with the wider LSA will idle slightly better, have slightly lower peak torque, and carry the torque to a little higher RPM. Probably not even a 2% difference in any of those things. The one with the narrower LSA will make slightly more torque but will tend slightly more to ping (might need a slightly less aggressive timing curve); again, emphasis on "slightly". VERY slightly.
I doubt anybody will even know the difference actually, even on a dyno; the difference is within normal variation between motors anyway.
Thread Starter
Joined: Feb 2015
Posts: 6,020
Likes: 2,299
From: Conroe, Texas
Thanks for the input everyone.. So as it stands right now I've got a 1 and 7 chance of having an engine with the wider LSA on the stand. I have no idea what this came out of and I really don't want to swap the cams as the engine on the stand is a low mileage engine. I'm just gonna throw it and go and use this new foundation for the LS1 parts I was able to salvage from my LS1.
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Thread Starter
Joined: Feb 2015
Posts: 6,020
Likes: 2,299
From: Conroe, Texas
Noticed I a sheared bolt in the cylinder head of my replacement engine and snapped an EZ-out into the it. Always something!
Needless to say trying to break it up into tiny pieces to get it out was a no go!
Persistence prevails! Now I can get the manifolds on and drop this into the truck.
Shes's in!
Finally got this thing all buttoned up and its now time for the much anticipated start up.
Thread Starter
Joined: Feb 2015
Posts: 6,020
Likes: 2,299
From: Conroe, Texas
Maybe its just me but I think I have the wider LSA cam in this motor, none the less the truck is running great and I now have an Iron LS1 project build in the works.
Back to stock 5.3 cams go, with the later 114 LSA . Another stock 5.3 cam you might consider is the L33 which had 2-3* more duration ,more lift ,482 but on a wider 116 LSA it will make more peak hp