Rate This Cam for a LSX 454
12-25-2018, 12:01 PM
#1
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Rate This Cam for a LSX 454 Hey all,
I had this cam spec’d for my LSX 454. I would like to get your thoughts on this.
Cam specs:
236/248 .634"/.634" 117LSA +3 advance (with 1.8 ratio rockers)
Engine is an LSX 454 with RHS Pro Elite LS7 cylinder heads.
Engine bore is 4.185. Stroke is 4.125 and 6.125 rods.
Click Here to view cylinder heads and specs.
Please let me know what you think of this cam?
I wanted a powerful yet tame(ish) cam that wouldn’t give me a headache since the car is pure street.
Thanks
I had this cam spec’d for my LSX 454. I would like to get your thoughts on this.
Cam specs:
236/248 .634"/.634" 117LSA +3 advance (with 1.8 ratio rockers)
Engine is an LSX 454 with RHS Pro Elite LS7 cylinder heads.
Engine bore is 4.185. Stroke is 4.125 and 6.125 rods.
Click Here to view cylinder heads and specs.
Please let me know what you think of this cam?
I wanted a powerful yet tame(ish) cam that wouldn’t give me a headache since the car is pure street.
Thanks
12-25-2018, 01:20 PM
#2
Looks pretty close to the original cam which was 236/246 @ .050" with .648"/.648" lift, except the original cam is on a 110+1 LSA and has 21 degrees of overlap.
I'd say it's going to make about the same peak power, but the bottom end will lose a few lbft below peak torque.
I'd say it's going to make about the same peak power, but the bottom end will lose a few lbft below peak torque.
12-25-2018, 02:02 PM
#3
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I would call it small myself but yeah it will be tame
12-25-2018, 02:22 PM
#4
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I agree with Darth, it’s smallish for the cubes your running. Cubic inches absorb duration well, meaning a big cam won’t “feel” as big in a bigger engine. I don’t spec cams, even for myself, but I’d shoot for a 240/254ish cam if I had a 454, and wanted it tame. My 434 is a 254/268 solid ( 246/260 hydraulic equivalent) and it’s very streetable, but not tame, if you follow me.
12-25-2018, 02:50 PM
#5
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I have a 243/259 on a 114 separation and 660 lift in my 454 it is a good all around cam with very little surging at all. For a stick car surging can really be a nuisance.
12-25-2018, 02:56 PM
#6
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I agree with Darth, it’s smallish for the cubes your running. Cubic inches absorb duration well, meaning a big cam won’t “feel” as big in a bigger engine. I don’t spec cams, even for myself, but I’d shoot for a 240/254ish cam if I had a 454, and wanted it tame. My 434 is a 254/268 solid ( 246/260 hydraulic equivalent) and it’s very streetable, but not tame, if you follow me.
Looks pretty close to the original cam which was 236/246 @ .050" with .648"/.648" lift, except the original cam is on a 110+1 LSA and has 21 degrees of overlap.
I'd say it's going to make about the same peak power, but the bottom end will lose a few lbft below peak torque.
I'd say it's going to make about the same peak power, but the bottom end will lose a few lbft below peak torque.
The cam that was previously in when I bought the car was a texas giant cam. 248/254, .615"/.622" 112 LSA. Tuning that thing was a total mess even the idle was never a 100%. Driving it was equally bad. Not very streetable.
I installed this new cam and it seems more powerful all over. The previous one died at 6400 rpm. This new one keeps going all the way to the redline at 7100 rpm.
I’m confused. This is why I made this post.
Can smaller cams outperform bigger cams in terms of power and tq? Is it always about the size?
What cam would you run in this thing?
12-25-2018, 05:28 PM
#7
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Originally Posted by 20SS06
Thanks for the input.
The cam that was previously in when I bought the car was a texas giant cam. 248/254, .615"/.622" 112 LSA. Tuning that thing was a total mess even the idle was never a 100%. Driving it was equally bad. Not very streetable.
I installed this new cam and it seems more powerful all over. The previous one died at 6400 rpm. This new one keeps going all the way to the redline at 7100 rpm.
I’m confused. This is why I made this post.
Can smaller cams outperform bigger cams in terms of power and tq? Is it always about the size?
What cam would you run in this thing?
The cam that was previously in when I bought the car was a texas giant cam. 248/254, .615"/.622" 112 LSA. Tuning that thing was a total mess even the idle was never a 100%. Driving it was equally bad. Not very streetable.
I installed this new cam and it seems more powerful all over. The previous one died at 6400 rpm. This new one keeps going all the way to the redline at 7100 rpm.
I’m confused. This is why I made this post.
Can smaller cams outperform bigger cams in terms of power and tq? Is it always about the size?
What cam would you run in this thing?
Yes I have seen smaller cams outperform larger cams. I am surprised in this case though. That cam never should have rolled over at 6400. My 247/255 in the 428 will peak at 7000 and carry damn near to 8000.
But, if you are happy with the cam you have, then you should just go enjoy it. What I consider streetable some consider race only and others consider too tame.
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12-25-2018, 05:33 PM
#8
236/248 .634"/.634" 117LSA +3 - definitely agree this a small cam for a 454. I'm a fan of smaller and medium cams. With a good tune I think you could go larger and keep very good drive ability.
The lobe profile has a big impact on power. A smaller cam that has well designed valve events, an excellent lobe spec'd by a cam guru could make more power than a bigger cam that's not correctly spec'd.
My 416 has 237/245 ~.625/.625 lift 114 LSA, drives good, I could easily see something like a ~ 240/250 ~.635/.635 lift 114 LSA drive well in a 454.
The lobe profile has a big impact on power. A smaller cam that has well designed valve events, an excellent lobe spec'd by a cam guru could make more power than a bigger cam that's not correctly spec'd.
My 416 has 237/245 ~.625/.625 lift 114 LSA, drives good, I could easily see something like a ~ 240/250 ~.635/.635 lift 114 LSA drive well in a 454.
Last edited by 99 Black Bird T/A; 12-25-2018 at 05:47 PM.
12-25-2018, 09:52 PM
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It does not matter what any of us think. If you are happy with it that is what matters.
Yes I have seen smaller cams outperform larger cams. I am surprised in this case though. That cam never should have rolled over at 6400. My 247/255 in the 428 will peak at 7000 and carry damn near to 8000.
But, if you are happy with the cam you have, then you should just go enjoy it. What I consider streetable some consider race only and others consider too tame.
Yes I have seen smaller cams outperform larger cams. I am surprised in this case though. That cam never should have rolled over at 6400. My 247/255 in the 428 will peak at 7000 and carry damn near to 8000.
But, if you are happy with the cam you have, then you should just go enjoy it. What I consider streetable some consider race only and others consider too tame.
236/248 .634"/.634" 117LSA +3 - definitely agree this a small cam for a 454. I'm a fan of smaller and medium cams. With a good tune I think you could go larger and keep very good drive ability.
The lobe profile has a big impact on power. A smaller cam that has well designed valve events, an excellent lobe spec'd by a cam guru could make more power than a bigger cam that's not correctly spec'd.
My 416 has 237/245 ~.625/.625 lift 114 LSA, drives good, I could easily see something like a ~ 240/250 ~.635/.635 lift 114 LSA drive well in a 454.
The lobe profile has a big impact on power. A smaller cam that has well designed valve events, an excellent lobe spec'd by a cam guru could make more power than a bigger cam that's not correctly spec'd.
My 416 has 237/245 ~.625/.625 lift 114 LSA, drives good, I could easily see something like a ~ 240/250 ~.635/.635 lift 114 LSA drive well in a 454.
Will it be worth the trouble of having to pay for a new one plus shipping plus install?
The whole process of buying and installing the cam cost me $1700. Is it worth doing it again and again till I get it right?
How many cams does one have to try to get it right?
12-25-2018, 10:17 PM
#10
Whether it's worth it depends on what you want, how much you want it, and what you're willing to trade off.
If you want more top end power, how much low end are you willing to trade off? Is it OK if the fun part of the powerband starts 500 or 1000 RPM higher? Or does do you wish the power came on sooner? Do you like your rev limiter where it is, or would you like to make it higher or lower, and tailor the next cam accordingly? Is it OK if the top of the powerband tapers off sooner, so you can get a little more power at lower RPM - or would you rather do the opposite? How much does it surge now, and how much are you willing to put up with?
When you have a good idea of what your goals and constraints are, then you can get some idea of what a new cam can do to approach those goals, within those constraints... and then decide whether that's worth another $1700 or so.
12-26-2018, 12:36 AM
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Whether it's worth it depends on what you want, how much you want it, and what you're willing to trade off.
If you want more top end power, how much low end are you willing to trade off? Is it OK if the fun part of the powerband starts 500 or 1000 RPM higher? Or does do you wish the power came on sooner? Do you like your rev limiter where it is, or would you like to make it higher or lower, and tailor the next cam accordingly? Is it OK if the top of the powerband tapers off sooner, so you can get a little more power at lower RPM - or would you rather do the opposite? How much does it surge now, and how much are you willing to put up with?
When you have a good idea of what your goals and constraints are, then you can get some idea of what a new cam can do to approach those goals, within those constraints... and then decide whether that's worth another $1700 or so.
If you want more top end power, how much low end are you willing to trade off? Is it OK if the fun part of the powerband starts 500 or 1000 RPM higher? Or does do you wish the power came on sooner? Do you like your rev limiter where it is, or would you like to make it higher or lower, and tailor the next cam accordingly? Is it OK if the top of the powerband tapers off sooner, so you can get a little more power at lower RPM - or would you rather do the opposite? How much does it surge now, and how much are you willing to put up with?
When you have a good idea of what your goals and constraints are, then you can get some idea of what a new cam can do to approach those goals, within those constraints... and then decide whether that's worth another $1700 or so.
12-26-2018, 05:57 AM
#12
Apologies for the long rambling post sharing my limited experience.
So how much power am I leaving on the table with this “small” cam?
Many factors play into that question. Has the car been dyno'd? It would be best to know where the set up is now hp& torque wise before speculation. What intake manifold and transmission does the car have?
Will it be worth the trouble of having to pay for a new one plus shipping plus install?
The whole process of buying and installing the cam cost me $1700. Is it worth doing it again and again till I get it right?
I'd define right as when the owner is happy with the drive ability, power and reliability of the set up. Sounds like the car drives good and is getting better. The specs for the cam aren't insane so it seems like it should be reliable. I would have to dyno the car and see what it makes or run at the track and see how it runs before I could decide if I were in your position. I'm also one of the few small to medium cam fans on the forum. Personally, with an six speed manual transmission, I would want to see 600 whp out of a 454. If it make 575 whp and drove well I would be content and not change cams. Many folks would want 650+ so it's really a matter of personal taste & budget.
My 91 RS has a 383 LS1 & a baby 229/229 cam only makes 465 whp. The car drives like stock. In truth folks have laughed at the low whp my 91 RS car makes and the mild exhaust sound. With more cam and better intake there is probably 35+ whp to be had. Respect from peers would be 500whp-520whp. I have drive the car, pay for repairs And upgrades, so I'm very happy with the car "as is" . Someone sensitive to peer pressure would want to make upgrades. One of my close friends has said for 3 years he'd want at least 800 whp out of same 383 LS1 and it needs a Procharger - badly...because the RS going to get gaptized and my *** handed to me with just 465 whp. The RS is a fun mild mannered street car that drives nice and does 1,300 mile road trips with ease - that's what makes me happy
The next $1,700 spent on the car will be for better tires, keyless entry, better floor mats & new window tint.
If your happy with the way your car drives there might be better choices to spend $1,700 on than another cam.
How many cams does one have to try to get it right?
I think you have to set your goal and measure to answer that question. If you work with top notch cam guru, like Darin Morgan of Reher-Morrison and explain you set up and what you want usually it's one cam and done. When Darin spec'd the cam for my 416, I told him the details of the motor, it had to drive well, make at least 500whp, use stock rockers with .~.625 lift, live for at least 50,000-60,000 miles and be reliable. Darin hit all of the requirements. He said proved the tuner was decent his cam would make 500whp-550whp in my set up My TA made 517whp and I made a few mistakes like leaving a stock WIX air filter in the car instead of a free flowing Green filter. If the TA had made lesson than 500 whp I would have been upset and started chasing 500 whp with some tweaks and changes.
I'm sure we could have got 575whp with a more aggressive low lash solid roller cam, better lifters, mid runners on the Fast 102, better fuel pump, Yella Terra rockers or Jesel's etc. In a couple of years if I get bored with the TA, I can call Darin and get one of his more "radical cams". For now 400 wtq at 2,800 rpm and a big fat low end torque curve sure is fun to drive
I'd dyno the 454 and see what it makes. If you have a 4L60e or 4L80e with stall it will really take a 1/4 mile run and trap speed to judge.
Your 454 sounds like a great set up for a street car to me.
If you decide to do another cam, Lingenfelter might also be worth contacting. One of their popular bigger 427 cams might be just right in a 454.
Lingenfelter GT21 Hydraulic Roller Camshaft 427 CID Corvette LS7 ZO6
So how much power am I leaving on the table with this “small” cam?
Many factors play into that question. Has the car been dyno'd? It would be best to know where the set up is now hp& torque wise before speculation. What intake manifold and transmission does the car have?
Will it be worth the trouble of having to pay for a new one plus shipping plus install?
The whole process of buying and installing the cam cost me $1700. Is it worth doing it again and again till I get it right?
I'd define right as when the owner is happy with the drive ability, power and reliability of the set up. Sounds like the car drives good and is getting better. The specs for the cam aren't insane so it seems like it should be reliable. I would have to dyno the car and see what it makes or run at the track and see how it runs before I could decide if I were in your position. I'm also one of the few small to medium cam fans on the forum. Personally, with an six speed manual transmission, I would want to see 600 whp out of a 454. If it make 575 whp and drove well I would be content and not change cams. Many folks would want 650+ so it's really a matter of personal taste & budget.
My 91 RS has a 383 LS1 & a baby 229/229 cam only makes 465 whp. The car drives like stock. In truth folks have laughed at the low whp my 91 RS car makes and the mild exhaust sound. With more cam and better intake there is probably 35+ whp to be had. Respect from peers would be 500whp-520whp. I have drive the car, pay for repairs And upgrades, so I'm very happy with the car "as is" . Someone sensitive to peer pressure would want to make upgrades. One of my close friends has said for 3 years he'd want at least 800 whp out of same 383 LS1 and it needs a Procharger - badly...because the RS going to get gaptized and my *** handed to me with just 465 whp. The RS is a fun mild mannered street car that drives nice and does 1,300 mile road trips with ease - that's what makes me happy
The next $1,700 spent on the car will be for better tires, keyless entry, better floor mats & new window tint.
If your happy with the way your car drives there might be better choices to spend $1,700 on than another cam.
How many cams does one have to try to get it right?
I think you have to set your goal and measure to answer that question. If you work with top notch cam guru, like Darin Morgan of Reher-Morrison and explain you set up and what you want usually it's one cam and done. When Darin spec'd the cam for my 416, I told him the details of the motor, it had to drive well, make at least 500whp, use stock rockers with .~.625 lift, live for at least 50,000-60,000 miles and be reliable. Darin hit all of the requirements. He said proved the tuner was decent his cam would make 500whp-550whp in my set up My TA made 517whp and I made a few mistakes like leaving a stock WIX air filter in the car instead of a free flowing Green filter. If the TA had made lesson than 500 whp I would have been upset and started chasing 500 whp with some tweaks and changes.
I'm sure we could have got 575whp with a more aggressive low lash solid roller cam, better lifters, mid runners on the Fast 102, better fuel pump, Yella Terra rockers or Jesel's etc. In a couple of years if I get bored with the TA, I can call Darin and get one of his more "radical cams". For now 400 wtq at 2,800 rpm and a big fat low end torque curve sure is fun to drive
I'd dyno the 454 and see what it makes. If you have a 4L60e or 4L80e with stall it will really take a 1/4 mile run and trap speed to judge.
Your 454 sounds like a great set up for a street car to me.
If you decide to do another cam, Lingenfelter might also be worth contacting. One of their popular bigger 427 cams might be just right in a 454.
Lingenfelter GT21 Hydraulic Roller Camshaft 427 CID Corvette LS7 ZO6
Last edited by 99 Black Bird T/A; 12-26-2018 at 06:48 AM.
12-26-2018, 06:52 AM
#13
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Apologies for the long rambling post sharing my limited experience.
So how much power am I leaving on the table with this “small” cam?
Many factors play into that question. Has the car been dyno'd? It would be best to know where the set up is now hp& torque wise before speculation. What intake manifold and transmission does the car have?
Will it be worth the trouble of having to pay for a new one plus shipping plus install?
The whole process of buying and installing the cam cost me $1700. Is it worth doing it again and again till I get it right?
I'd define right as when the owner is happy with the drive ability, power and reliability of the set up. Sounds like the car drives good and is getting better. The specs for the cam aren't insane so it seems like it should be reliable. I would have to dyno the car and see what it makes or run at the track and see how it runs before I could decide if I were in your position. I'm also one of the few small to medium cam fans on the forum. Personally, with an six speed manual transmission, I would want to see 600 whp out of a 454. If it make 575 whp and drove well I would be content and not change cams. Many folks would want 650+ so it's really a matter of personal taste & budget.
My 91 RS has a 383 LS1 & a baby 229/229 cam only makes 465 whp. The car drives like stock. In truth folks have laughed at the low whp my 91 RS car makes and the mild exhaust sound. With more cam and better intake there is probably 35+ whp to be had. Respect from peers would be 500whp-520whp. I have drive the car, pay for repairs And upgrades, so I'm very happy with the car "as is" . Someone sensitive to peer pressure would want to make upgrades. One of my close friends has said for 3 years he'd want at least 800 whp out of same 383 LS1 and it needs a Procharger - badly...because the RS going to get gaptized and my *** handed to me with just 465 whp. The RS is a fun mild mannered street car that drives nice and does 1,300 mile road trips with ease - that's what makes me happy
The next $1,700 spent on the car will be for better tires, keyless entry, better floor mats & new window tint.
If your happy with the way your car drives there might be better choices to spend $1,700 on than another cam.
How many cams does one have to try to get it right?
I think you have to set your goal and measure to answer that question. If you work with top notch cam guru, like Darin Morgan of Reher-Morrison and explain you set up and what you want usually it's one cam and done. When Darin spec'd the cam for my 416, I told him the details of the motor, it had to drive well, make at least 500whp, use stock rockers with .~.625 lift, live for at least 50,000-60,000 miles and be reliable. Darin hit all of the requirements. He said proved the tuner was decent his cam would make 500whp-550whp in my set up My TA made 517whp and I made a few mistakes like leaving a stock WIX air filter in the car instead of a free flowing Green filter. If the TA had made lesson than 500 whp I would have been upset and started chasing 500 whp with some tweaks and changes.
I'm sure we could have got 575whp with a more aggressive low lash solid roller cam, better lifters, mid runners on the Fast 102, better fuel pump, Yella Terra rockers or Jesel's etc. In a couple of years if I get bored with the TA, I can call Darin and get one of his more "radical cams". For now 400 wtq at 2,800 rpm and a big fat low end torque curve sure is fun to drive
I'd dyno the 454 and see what it makes. If you have a 4L60e or 4L80e with stall it will really take a 1/4 mile run and trap speed to judge.
Your 454 sounds like a great set up for a street car to me
So how much power am I leaving on the table with this “small” cam?
Many factors play into that question. Has the car been dyno'd? It would be best to know where the set up is now hp& torque wise before speculation. What intake manifold and transmission does the car have?
Will it be worth the trouble of having to pay for a new one plus shipping plus install?
The whole process of buying and installing the cam cost me $1700. Is it worth doing it again and again till I get it right?
I'd define right as when the owner is happy with the drive ability, power and reliability of the set up. Sounds like the car drives good and is getting better. The specs for the cam aren't insane so it seems like it should be reliable. I would have to dyno the car and see what it makes or run at the track and see how it runs before I could decide if I were in your position. I'm also one of the few small to medium cam fans on the forum. Personally, with an six speed manual transmission, I would want to see 600 whp out of a 454. If it make 575 whp and drove well I would be content and not change cams. Many folks would want 650+ so it's really a matter of personal taste & budget.
My 91 RS has a 383 LS1 & a baby 229/229 cam only makes 465 whp. The car drives like stock. In truth folks have laughed at the low whp my 91 RS car makes and the mild exhaust sound. With more cam and better intake there is probably 35+ whp to be had. Respect from peers would be 500whp-520whp. I have drive the car, pay for repairs And upgrades, so I'm very happy with the car "as is" . Someone sensitive to peer pressure would want to make upgrades. One of my close friends has said for 3 years he'd want at least 800 whp out of same 383 LS1 and it needs a Procharger - badly...because the RS going to get gaptized and my *** handed to me with just 465 whp. The RS is a fun mild mannered street car that drives nice and does 1,300 mile road trips with ease - that's what makes me happy
The next $1,700 spent on the car will be for better tires, keyless entry, better floor mats & new window tint.
If your happy with the way your car drives there might be better choices to spend $1,700 on than another cam.
How many cams does one have to try to get it right?
I think you have to set your goal and measure to answer that question. If you work with top notch cam guru, like Darin Morgan of Reher-Morrison and explain you set up and what you want usually it's one cam and done. When Darin spec'd the cam for my 416, I told him the details of the motor, it had to drive well, make at least 500whp, use stock rockers with .~.625 lift, live for at least 50,000-60,000 miles and be reliable. Darin hit all of the requirements. He said proved the tuner was decent his cam would make 500whp-550whp in my set up My TA made 517whp and I made a few mistakes like leaving a stock WIX air filter in the car instead of a free flowing Green filter. If the TA had made lesson than 500 whp I would have been upset and started chasing 500 whp with some tweaks and changes.
I'm sure we could have got 575whp with a more aggressive low lash solid roller cam, better lifters, mid runners on the Fast 102, better fuel pump, Yella Terra rockers or Jesel's etc. In a couple of years if I get bored with the TA, I can call Darin and get one of his more "radical cams". For now 400 wtq at 2,800 rpm and a big fat low end torque curve sure is fun to drive
I'd dyno the 454 and see what it makes. If you have a 4L60e or 4L80e with stall it will really take a 1/4 mile run and trap speed to judge.
Your 454 sounds like a great set up for a street car to me
My intake is a Fast 102 and transmission is a manual tr6060. Also running this for my rockers.
I completely agree with what you said. And yes, I would like my car to have at least 600 whp given that it’s a 454. That’s actually the main reason I bought this car. I wanted to have a maxed out NA setup. I wanted a change from boost. Been running superchargers and turbos for a while and this is my first time doing a full on NA setup.
I’ve attached a video of my stroker turbo truck that I sold around a month ago. Was a real fun project. My new car is an 08 C6 Z06 with the LSX 454. My goal is definitely to make the most power I can with great drivability and street manners.
In case you’re wondering, the car I’m running against in the video is a 2018 Lamborghini Aventador S.
12-26-2018, 11:22 AM
#14
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OK, after digesting things and doing some calculations, I think I see what might be going on. Both of your cams have a pretty distinct "cathedral" look to them. Typically with rectangle or square ports, you would see a wider split. My guess is that you actually have LS7-style heads. I'm also guessing you are at 11.5:1 compression range.
Your cam specs aren't bad. IVc is at 52 degrees, which is pretty good for a LS7 (427) with a 4" stroke. Your EVO is about 64, which is where I would put it. It looks like someone took the previous cam and kept the IVC and EVO and just moved IVO and EVC around to get overlap down. not a bad approach to be honest. You just don't have alot of overlap, which is fine. I think if it were mine, I'd bump both the cam and compression. I think you'd really do better with a 54 degree IVC with that 4.125 stroke, and a little more split for the exhaust duration.
IF you were to go back in for surgery (and I would only do this if you TRULY are not happy) I would go 242/254-115+2 AND bump static compression to 12.2-12.3. That will put your IVC at 54 degrees instead of 52 and keep overlap in check at 18 degrees vs 8 on smaller cam or 27 on larger cam.
On the intake, I would ditch the fast 102 for something with shorter runners or a sheet metal intake. Larger cube engines don't need the larger runners to create airspeed in the ports. Thing is, for that kind of money, you might do better just to keep the engine as is and put a ITB on it for the same money, pay no drivability penalty AND gain the power, torque, and throttle response.
Your cam specs aren't bad. IVc is at 52 degrees, which is pretty good for a LS7 (427) with a 4" stroke. Your EVO is about 64, which is where I would put it. It looks like someone took the previous cam and kept the IVC and EVO and just moved IVO and EVC around to get overlap down. not a bad approach to be honest. You just don't have alot of overlap, which is fine. I think if it were mine, I'd bump both the cam and compression. I think you'd really do better with a 54 degree IVC with that 4.125 stroke, and a little more split for the exhaust duration.
IF you were to go back in for surgery (and I would only do this if you TRULY are not happy) I would go 242/254-115+2 AND bump static compression to 12.2-12.3. That will put your IVC at 54 degrees instead of 52 and keep overlap in check at 18 degrees vs 8 on smaller cam or 27 on larger cam.
On the intake, I would ditch the fast 102 for something with shorter runners or a sheet metal intake. Larger cube engines don't need the larger runners to create airspeed in the ports. Thing is, for that kind of money, you might do better just to keep the engine as is and put a ITB on it for the same money, pay no drivability penalty AND gain the power, torque, and throttle response.
12-26-2018, 12:01 PM
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12-26-2018, 12:14 PM
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OK, after digesting things and doing some calculations, I think I see what might be going on. Both of your cams have a pretty distinct "cathedral" look to them. Typically with rectangle or square ports, you would see a wider split. My guess is that you actually have LS7-style heads. I'm also guessing you are at 11.5:1 compression range.
Your cam specs aren't bad. IVc is at 52 degrees, which is pretty good for a LS7 (427) with a 4" stroke. Your EVO is about 64, which is where I would put it. It looks like someone took the previous cam and kept the IVC and EVO and just moved IVO and EVC around to get overlap down. not a bad approach to be honest. You just don't have alot of overlap, which is fine. I think if it were mine, I'd bump both the cam and compression. I think you'd really do better with a 54 degree IVC with that 4.125 stroke, and a little more split for the exhaust duration.
IF you were to go back in for surgery (and I would only do this if you TRULY are not happy) I would go 242/254-115+2 AND bump static compression to 12.2-12.3. That will put your IVC at 54 degrees instead of 52 and keep overlap in check at 18 degrees vs 8 on smaller cam or 27 on larger cam.
On the intake, I would ditch the fast 102 for something with shorter runners or a sheet metal intake. Larger cube engines don't need the larger runners to create airspeed in the ports. Thing is, for that kind of money, you might do better just to keep the engine as is and put a ITB on it for the same money, pay no drivability penalty AND gain the power, torque, and throttle response.
Your cam specs aren't bad. IVc is at 52 degrees, which is pretty good for a LS7 (427) with a 4" stroke. Your EVO is about 64, which is where I would put it. It looks like someone took the previous cam and kept the IVC and EVO and just moved IVO and EVC around to get overlap down. not a bad approach to be honest. You just don't have alot of overlap, which is fine. I think if it were mine, I'd bump both the cam and compression. I think you'd really do better with a 54 degree IVC with that 4.125 stroke, and a little more split for the exhaust duration.
IF you were to go back in for surgery (and I would only do this if you TRULY are not happy) I would go 242/254-115+2 AND bump static compression to 12.2-12.3. That will put your IVC at 54 degrees instead of 52 and keep overlap in check at 18 degrees vs 8 on smaller cam or 27 on larger cam.
On the intake, I would ditch the fast 102 for something with shorter runners or a sheet metal intake. Larger cube engines don't need the larger runners to create airspeed in the ports. Thing is, for that kind of money, you might do better just to keep the engine as is and put a ITB on it for the same money, pay no drivability penalty AND gain the power, torque, and throttle response.
You hit the bail on the head with your guess. Compression is 11.5:1 and the heads are LS7 style.
I would definitely keep your cam spec in mind if I were to decide to undergo the surgery. You seem to know your cams.
How much of a difference would I see with your spec as compared to the one I have?
I don’t want to raise compression much as the weather here is already compressed enough LoL. Welcome to Arabia
I might look at an ITB or sheet metal manifolds for now.
Thanks
12-26-2018, 12:18 PM
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12-26-2018, 12:35 PM
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If you swapped that cam in, likely gain 15-20. Mainly from rpm. If you peak a few hundred rpm higher your HP number will be automatically higher. You might just as easily gain that from a better intake too. Depending on your runner length in your fast. Even swapping in the short runners might make a surprising difference. And less intrusive than a cam swap.