Question about cam advance.
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Question about cam advance.
Have a question about cam advance. I was wondering if you advance a cam two degrees (double roller chain) what difference does it make in the IVC. My cam has a IVC of 53. Which might be a little late. Seems to lack low end torque a little. I would like to get some torque back.
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Some looks but no responses. I've been kicking around some new cam specs based on some past combos. I'm trying to figure out some valve events on a new cam I thought about. I tried the spreed sheet but I don't have excel. XER or XFI
dur.050 238/242
lsa 112
installed at 110 lobe sep.(+2)
16 degress overlap
Should be good N/A and 200 shot.
Motor is 12/1 comp speed inc 348
Maybe Predator or Pat G can chime in.
dur.050 238/242
lsa 112
installed at 110 lobe sep.(+2)
16 degress overlap
Should be good N/A and 200 shot.
Motor is 12/1 comp speed inc 348
Maybe Predator or Pat G can chime in.
Last edited by LS1 BU; 08-23-2008 at 06:24 PM.
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Just trying to get a 12 comp motor to run on pump gas and make good tq. My last cam which was on the limit of running on pump gas had a IVC of 47 degrees. My current cam has a IVC of 53 which makes it run on pump gas but lost power down low. Just trying to find a happy medium. The cam that I speced is XER
238/242
.6xx/.6xx
intake center line 110(+2)
lobe sep 112
16 degrees overlap
IVC of 49 degrees.
I think this cam should be a good na/nos cam.
238/242
.6xx/.6xx
intake center line 110(+2)
lobe sep 112
16 degrees overlap
IVC of 49 degrees.
I think this cam should be a good na/nos cam.
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Have a question about cam advance. I was wondering if you advance a cam two degrees (double roller chain) what difference does it make in the IVC. My cam has a IVC of 53. Which might be a little late. Seems to lack low end torque a little. I would like to get some torque back.
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238/242 112+4 you want, which I get IVC of 47*(will vary on certain lobes/cam companys). And you want to move your rpm sooner I take it. I would use a smaller cam IMO, and tighten up the LDA. You can try speeding the cam up more 2* that will help a little, (cam is BIG), but the intake mainfold has alot to do where the motor peaks also.
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Just trying to make good low end power My last cam had a IVC of 47 degrees but it would not run on straight 93 octane. After we pulled a little timing and added fuel it would run fine. Unless hot outside. It would get some knock. Current cam has a IVC of 53 and runs on 93. When I swaped cams I lost 14 rwtq at peak and alot under the curve. 4000-5000 area. Just trying to get some of the power back and run on 93 octane. That's why I went with 2 advance to get the IVC of 49
Current cam is 240/244 LSK lobes.
lobe sep 113.5
intake centerline 113.0
with IVC 53
15 degress overlap.
Previous cam is LSK/XER
235/240
lobe sep 111
intake centerline 109.5
15 degrees overlap
IVC of 47
Current cam is 240/244 LSK lobes.
lobe sep 113.5
intake centerline 113.0
with IVC 53
15 degress overlap.
Previous cam is LSK/XER
235/240
lobe sep 111
intake centerline 109.5
15 degrees overlap
IVC of 47
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Just trying to make good low end power My last cam had a IVC of 47 degrees but it would not run on straight 93 octane. After we pulled a little timing and added fuel it would run fine. Unless hot outside. It would get some knock. Current cam has a IVC of 53 and runs on 93. When I swaped cams I lost 14 rwtq at peak and alot under the curve. 4000-5000 area. Just trying to get some of the power back and run on 93 octane. That's why I went with 2 advance to get the IVC of 49
Current cam is 240/244 LSK lobes.
lobe sep 113.5
intake centerline 113.0
with IVC 53
15 degress overlap.
Previous cam is LSK/XER
235/240
lobe sep 111
intake centerline 109.5
15 degrees overlap
IVC of 47
Current cam is 240/244 LSK lobes.
lobe sep 113.5
intake centerline 113.0
with IVC 53
15 degress overlap.
Previous cam is LSK/XER
235/240
lobe sep 111
intake centerline 109.5
15 degrees overlap
IVC of 47
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I shift a 7000 rpm and rev to 7300. That's not an issue. Just trying to close the intake valve a little sooner to get dcr back to where it should be. I don't have the formula to figure it out. I have a 12/1 compression motor with the cams that i have run. I estimate my compression with new cam specd at IVC of 49 should put me in the 8.80-8.90 area. That should work on 93 octane.
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I shift a 7000 rpm and rev to 7300. That's not an issue. Just trying to close the intake valve a little sooner to get dcr back to where it should be. I don't have the formula to figure it out. I have a 12/1 compression motor with the cams that i have run. I estimate my compression with new cam specd at IVC of 49 should put me in the 8.80-8.90 area. That should work on 93 octane.
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47.5 IVC
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Hey predator can you help me figure out DCR with cam setup. Motor is 348 at 12/1 static compression. Still not sure which lobe I would run. I've run LSK lobes and XER lobes. Don't have experience with XFI lobes. I have springs setup to run LSK lobes. Just have heard that they are hard on valvetrain parts. My heads are ET 215 heads.
. AT the same time I swaped cams had my fast 90/90 ported and went from macs to hooker 1 7/8 long tubes. I only picked up 6 hp up to and lost alot down low. I think the cam I specd should be a happy medium between the two and run on pump gas.
Current cam is 240/244 LSK lobes.
lobe sep 113.5
intake centerline 113.0
with IVC 53
15 degress overlap
Last cam is
235/240
lobe sep 111
intake centerline 109.5
15 degrees overlap
IVC of 47
new cam
238/242
.6xx/.6xx
intake center line 110(+2)
lobe sep 112
16 degrees overlap
IVC of 49 degrees.
I think this cam should be a good na/nos cam
new specd cam
. AT the same time I swaped cams had my fast 90/90 ported and went from macs to hooker 1 7/8 long tubes. I only picked up 6 hp up to and lost alot down low. I think the cam I specd should be a happy medium between the two and run on pump gas.
Current cam is 240/244 LSK lobes.
lobe sep 113.5
intake centerline 113.0
with IVC 53
15 degress overlap
Last cam is
235/240
lobe sep 111
intake centerline 109.5
15 degrees overlap
IVC of 47
new cam
238/242
.6xx/.6xx
intake center line 110(+2)
lobe sep 112
16 degrees overlap
IVC of 49 degrees.
I think this cam should be a good na/nos cam
new specd cam