First cam swap, LM7 engine
09-24-2020, 03:50 PM
#1
First cam swap, LM7 engine
So I've done a fair bit of research and come this winter Im gonna drop a cam in my LM7, in a 1999 silverado. Im pretty confident I can pull it off, I've never been this deep in an engine larger than 2 cylinder before though. Do any of you folks have advice before I go for it?
Cam will probably be a TSP 220r, duration is .220/.220, .600/.600 lift and 110LSA
Cam will probably be a TSP 220r, duration is .220/.220, .600/.600 lift and 110LSA
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CrazyCanuck317 (09-24-2020)
09-24-2020, 08:46 PM
#3
If it was me, and I was doing my 1st cam swap EVAH, I'd pick something smaller.
FFDP's 212/218 is exactly what I'd suggest. IMO the one you picked is too big.
A small motor in a heavy vehicle can tolerate a large cam (all such terms being relative), but THE VEHICLE needs some prep too. To make the above combo work, you need a BIG exhaust, a converter, and gears. You CANNOT withstand the motor being forced to live in a RPM range where the cam you have chosen is WORSE THAN STOCK.
There's no such thing as "too much cam". Only, "not enough motor", and maybe, "not enough car". Which is EXACTLY where you'll be.
I've lived through alot of humiliations and disappointments in my days; but I would have to say, that among THE WORST, was a motor I had in my younger and even more foolish days, where I chose a cam that gave up bottom end. The old "30-30" cam, for you old farts out there... a true racing monster for its day. But I EFFFFFFED up and put it in a street car. A 292 in a 3800 lb car with a close-ratio 4-speed and a 3.23 gear, no less. That sumbitch RIPPED, but had to be going AT LEAST 40 in 1st gear, otherwise I could watch the grass growing in the lawns I was in front of while some STOCK little bit of nothing 307 2-bbl disappeared in the distance in front of me. Sure, it could literally burn rubber at 55 in 1st, and turn the car sideways shifting to 2nd at 65; but as a daily driver urban bumper-to-bumper rush-hour commuter, it just ... didn't cut it.
I'd suggest the TSP "Stage 2 truck" low lift, with PAC 1218 springs. You won't spend NEAR as much time worrying about broken parts. Which I can SURELY ASSURE you, sucks every bit of fun out of this hobby.
And no matter what cam, even a stock one, you NEED a tune. That's probably the single biggest difference you can make. Even BEFORE a cam. Just like in the old days of diddling with jets and rods and power valves, and timing curves, and all that. Same thing. Nowadays the word for all that, as a package, is "tune".
FFDP's 212/218 is exactly what I'd suggest. IMO the one you picked is too big.
A small motor in a heavy vehicle can tolerate a large cam (all such terms being relative), but THE VEHICLE needs some prep too. To make the above combo work, you need a BIG exhaust, a converter, and gears. You CANNOT withstand the motor being forced to live in a RPM range where the cam you have chosen is WORSE THAN STOCK.
There's no such thing as "too much cam". Only, "not enough motor", and maybe, "not enough car". Which is EXACTLY where you'll be.
I've lived through alot of humiliations and disappointments in my days; but I would have to say, that among THE WORST, was a motor I had in my younger and even more foolish days, where I chose a cam that gave up bottom end. The old "30-30" cam, for you old farts out there... a true racing monster for its day. But I EFFFFFFED up and put it in a street car. A 292 in a 3800 lb car with a close-ratio 4-speed and a 3.23 gear, no less. That sumbitch RIPPED, but had to be going AT LEAST 40 in 1st gear, otherwise I could watch the grass growing in the lawns I was in front of while some STOCK little bit of nothing 307 2-bbl disappeared in the distance in front of me. Sure, it could literally burn rubber at 55 in 1st, and turn the car sideways shifting to 2nd at 65; but as a daily driver urban bumper-to-bumper rush-hour commuter, it just ... didn't cut it.
I'd suggest the TSP "Stage 2 truck" low lift, with PAC 1218 springs. You won't spend NEAR as much time worrying about broken parts. Which I can SURELY ASSURE you, sucks every bit of fun out of this hobby.
And no matter what cam, even a stock one, you NEED a tune. That's probably the single biggest difference you can make. Even BEFORE a cam. Just like in the old days of diddling with jets and rods and power valves, and timing curves, and all that. Same thing. Nowadays the word for all that, as a package, is "tune".
Last edited by RB04Av; 09-24-2020 at 08:53 PM.
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09-24-2020, 10:45 PM
#4
TSP Stage 2 gets my vote as well. It's exactly what I run and I really like it for a stock converter 4L60/5.3
have you read all the cam how to's? There aren't really any "gotchas" with this plan EXCEPT the oil pick up o-ring. For the love of god, use a new one, shim your pump and make ABSOLUTELY SURE the o-ring seats in the oil pump body
have you read all the cam how to's? There aren't really any "gotchas" with this plan EXCEPT the oil pick up o-ring. For the love of god, use a new one, shim your pump and make ABSOLUTELY SURE the o-ring seats in the oil pump body
The following users liked this post:
CrazyCanuck317 (09-24-2020)
09-24-2020, 11:42 PM
#5
TSP Stage 2 gets my vote as well. It's exactly what I run and I really like it for a stock converter 4L60/5.3
have you read all the cam how to's? There aren't really any "gotchas" with this plan EXCEPT the oil pick up o-ring. For the love of god, use a new one, shim your pump and make ABSOLUTELY SURE the o-ring seats in the oil pump body
have you read all the cam how to's? There aren't really any "gotchas" with this plan EXCEPT the oil pick up o-ring. For the love of god, use a new one, shim your pump and make ABSOLUTELY SURE the o-ring seats in the oil pump body
If it was me, and I was doing my 1st cam swap EVAH, I'd pick something smaller.
FFDP's 212/218 is exactly what I'd suggest. IMO the one you picked is too big.
A small motor in a heavy vehicle can tolerate a large cam (all such terms being relative), but THE VEHICLE needs some prep too. To make the above combo work, you need a BIG exhaust, a converter, and gears. You CANNOT withstand the motor being forced to live in a RPM range where the cam you have chosen is WORSE THAN STOCK.
There's no such thing as "too much cam". Only, "not enough motor", and maybe, "not enough car". Which is EXACTLY where you'll be.
I've lived through alot of humiliations and disappointments in my days; but I would have to say, that among THE WORST, was a motor I had in my younger and even more foolish days, where I chose a cam that gave up bottom end. The old "30-30" cam, for you old farts out there... a true racing monster for its day. But I EFFFFFFED up and put it in a street car. A 292 in a 3800 lb car with a close-ratio 4-speed and a 3.23 gear, no less. That sumbitch RIPPED, but had to be going AT LEAST 40 in 1st gear, otherwise I could watch the grass growing in the lawns I was in front of while some STOCK little bit of nothing 307 2-bbl disappeared in the distance in front of me. Sure, it could literally burn rubber at 55 in 1st, and turn the car sideways shifting to 2nd at 65; but as a daily driver urban bumper-to-bumper rush-hour commuter, it just ... didn't cut it.
I'd suggest the TSP "Stage 2 truck" low lift, with PAC 1218 springs. You won't spend NEAR as much time worrying about broken parts. Which I can SURELY ASSURE you, sucks every bit of fun out of this hobby.
And no matter what cam, even a stock one, you NEED a tune. That's probably the single biggest difference you can make. Even BEFORE a cam. Just like in the old days of diddling with jets and rods and power valves, and timing curves, and all that. Same thing. Nowadays the word for all that, as a package, is "tune".
FFDP's 212/218 is exactly what I'd suggest. IMO the one you picked is too big.
A small motor in a heavy vehicle can tolerate a large cam (all such terms being relative), but THE VEHICLE needs some prep too. To make the above combo work, you need a BIG exhaust, a converter, and gears. You CANNOT withstand the motor being forced to live in a RPM range where the cam you have chosen is WORSE THAN STOCK.
There's no such thing as "too much cam". Only, "not enough motor", and maybe, "not enough car". Which is EXACTLY where you'll be.
I've lived through alot of humiliations and disappointments in my days; but I would have to say, that among THE WORST, was a motor I had in my younger and even more foolish days, where I chose a cam that gave up bottom end. The old "30-30" cam, for you old farts out there... a true racing monster for its day. But I EFFFFFFED up and put it in a street car. A 292 in a 3800 lb car with a close-ratio 4-speed and a 3.23 gear, no less. That sumbitch RIPPED, but had to be going AT LEAST 40 in 1st gear, otherwise I could watch the grass growing in the lawns I was in front of while some STOCK little bit of nothing 307 2-bbl disappeared in the distance in front of me. Sure, it could literally burn rubber at 55 in 1st, and turn the car sideways shifting to 2nd at 65; but as a daily driver urban bumper-to-bumper rush-hour commuter, it just ... didn't cut it.
I'd suggest the TSP "Stage 2 truck" low lift, with PAC 1218 springs. You won't spend NEAR as much time worrying about broken parts. Which I can SURELY ASSURE you, sucks every bit of fun out of this hobby.
And no matter what cam, even a stock one, you NEED a tune. That's probably the single biggest difference you can make. Even BEFORE a cam. Just like in the old days of diddling with jets and rods and power valves, and timing curves, and all that. Same thing. Nowadays the word for all that, as a package, is "tune".
What about push rods and lifters? Ive heard a lot of conflicting opinions, but what I was thinking of settling on was upgraded pushrods but running the stock lifters
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09-25-2020, 07:16 AM
#8
09-25-2020, 11:22 AM
#9
TECH Resident
I did my first cam swap on a 99 GMC and I went with an off the wall cam choice because I wanted to boost it at some point. The cam specs were 218/230 .607/.604 on a 117LSA. If I could do it all over, I would have made a different cam choice(honestly a little bigger), and would have done a converter as well. No matter what the dyno sheets say or the manufacturer says, adding a cam is going to move the power band and a converter will make up for that. That's just my two cents.
09-25-2020, 07:15 PM
#10
I did my first cam swap on a 99 GMC and I went with an off the wall cam choice because I wanted to boost it at some point. The cam specs were 218/230 .607/.604 on a 117LSA. If I could do it all over, I would have made a different cam choice(honestly a little bigger), and would have done a converter as well. No matter what the dyno sheets say or the manufacturer says, adding a cam is going to move the power band and a converter will make up for that. That's just my two cents.
It belonged to my great grandfather, but saw very little use because it used too much gas. Only ever used for dump runs, it had about 10k on it when I inherited it in 2018.
