LS7 Cam Doctor results...
10-16-2012, 08:51 AM
#81
Could anyone see if this is a good cam for my application, and what kind of numbers I might make or how it will run.
LQ4 block
4.030 flat top pistons (somewhere around 10.5-8:1 I think)
Same stock stroke
LS7 cam
LS3 heads, lots of port work done (no flow numbers sorry, but very credible source)
Ls3 intake (not ported) and 90mm TB.
1 7/8 LT headers, 3" exhaust all way back with high flow cats and mufflers from magnalflow
Looking for a very streetable setup, N/A, that I can still take to the track and open up.
If you need more info to give me a better idea I'll try and get it for you. but thats about all I know so far.
thanks
EDIT: also, will this setup require the front cam sensor, or can I have it in either place?
LQ4 block
4.030 flat top pistons (somewhere around 10.5-8:1 I think)
Same stock stroke
LS7 cam
LS3 heads, lots of port work done (no flow numbers sorry, but very credible source)
Ls3 intake (not ported) and 90mm TB.
1 7/8 LT headers, 3" exhaust all way back with high flow cats and mufflers from magnalflow
Looking for a very streetable setup, N/A, that I can still take to the track and open up.
If you need more info to give me a better idea I'll try and get it for you. but thats about all I know so far.
thanks
EDIT: also, will this setup require the front cam sensor, or can I have it in either place?
Last edited by K11PER; 10-16-2012 at 10:13 AM.
02-26-2013, 08:52 PM
#84
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Project, I can't tell you about the LS7 cam, but there is an article in GMHTP where they put a LS9 cam (211/230 122.5 LSA .558/.552) in a 6.2 Silverado truck motor. They used LS3 valve springs, LS3 Timing Cover, and a 3 Bolt cam sprocket. Made +47 HP and 20.5 lb-ft for under $300, new parts from GM.
02-27-2013, 09:28 AM
#85
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Project, I can't tell you about the LS7 cam, but there is an article in GMHTP where they put a LS9 cam (211/230 122.5 LSA .558/.552) in a 6.2 Silverado truck motor. They used LS3 valve springs, LS3 Timing Cover, and a 3 Bolt cam sprocket. Made +47 HP and 20.5 lb-ft for under $300, new parts from GM.
The reason I was asking about the base circle is that ever since I've had the cam installed the valve train has made noise. I suspect that I need slightly longer pushrods, because I suspect the LS7 and LS9 cams have a smaller base circle than the L92 cams.
I was just looking for actual confirmation, but it doesn't look like anyone has firm numbers. I was trying to avoid using a pushrod length checker, but I might have to do just that.
Andrew
11-12-2013, 05:46 AM
#86
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I've actually been running the LS7 cam (which is very close to the LS9 cam) in my 1970 GTO with a L92, since 2008. The combo made 418rwph through a Richmond 6spd and 12 bolt rear end.
The reason I was asking about the base circle is that ever since I've had the cam installed the valve train has made noise. I suspect that I need slightly longer pushrods, because I suspect the LS7 and LS9 cams have a smaller base circle than the L92 cams.
I was just looking for actual confirmation, but it doesn't look like anyone has firm numbers. I was trying to avoid using a pushrod length checker, but I might have to do just that.
Andrew
The reason I was asking about the base circle is that ever since I've had the cam installed the valve train has made noise. I suspect that I need slightly longer pushrods, because I suspect the LS7 and LS9 cams have a smaller base circle than the L92 cams.
I was just looking for actual confirmation, but it doesn't look like anyone has firm numbers. I was trying to avoid using a pushrod length checker, but I might have to do just that.
Andrew
08-10-2015, 07:34 PM
#88
Staging Lane
08-11-2015, 02:03 PM
#89
Staging Lane
Most groups see an improvement from advancing the cam because it accounts for slack in the timing chain. You're better off installing the cam straight up and then using undersize/oversize timing gears to take all the slack out of the timing chain. Traditional smallblock and big block timing sets are available with oversize and undersize gears for blocks that have been machined.
I'm not sure if there are deliberately oversized gears for the LS series of engines, but back in the day when I had a 96 impala with an LT1, I had the engine block align bored. After the blueprinting, the cam and the crank were a few thousanths closer together, making for a fairly slack timing chain. What my engine builder did was order six LT4 timing sets, and mixed and matched gearsets and chains until he got a timing set that had no slack when installed in the block. Then he sent the other unused sets back for a refund. That's the correct way to do it, rather than advancing the cam to adjust for slack in the timing chain.
I'm not sure if there are deliberately oversized gears for the LS series of engines, but back in the day when I had a 96 impala with an LT1, I had the engine block align bored. After the blueprinting, the cam and the crank were a few thousanths closer together, making for a fairly slack timing chain. What my engine builder did was order six LT4 timing sets, and mixed and matched gearsets and chains until he got a timing set that had no slack when installed in the block. Then he sent the other unused sets back for a refund. That's the correct way to do it, rather than advancing the cam to adjust for slack in the timing chain.
12-29-2019, 11:52 AM
#91
TECH Senior Member
