Dumping The Voodoo
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From: northern california
C2 of Year Finalist (track prepared) 2019
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Joined: Nov 2003
Posts: 10,696
Likes: 3,091
From: Cottonwood AZ
C1 of Year Finalist (performance mods) 2019
You are probably tired of hearing me say this over and over but I can't stress how important it is to do thing RIGHT the first time rather than later when you car is not performing the way you hoped it would you have to go back into the engine and do it over again. Below is a copy and paste that I posted in one of you threads in the past that I think you should re-read. I have bolded some area that are of particular importance. I have also added some NEW info below in parentheses and bolded for your review.
OK, I have read all of your posts in the threads you have going on and am going to respond to what I believe is your goal for this car and with where your thinking is flawed.
First of all you need to determine how you are going to use the car. Is it going to be an around town car with occasional short freeway trips or are you going to use it primarily on the freeway? Most of us use our cars as the first option and if that is you as well you really can’t go wrong with the way you car was configured from the factory. I would not be concerned with gas mileage since you likely will not put that many miles on the car annually.
You want to switch to a higher speed rear end ratio I assume for either better mileage and or less high rpm engine wear on the highway. You believe that the original rear axle ratio is a 4.11 per the tag marking on the rear end. I don’t believe you could get a non posi 4.11 in a Corvette from the factory so if you have checked it correctly then likely the posi is worn out.
The factory combination of your original 340 h.p. and the 4.11 gears is pretty much the best performance combination available from the factory in 1962 (especially with the 4.11s) other than an FI car.
I know you have mentioned that you don’t want to spend a lot of money on this car and want to keep it as original looking as possible. I think that means no headers, stock carb and manifolds etc. Nothing is cheap these days and if you want your 57 year old car dependable then you need to spend the money required to make the engine as such.
You want to increase h.p. by cutting compression to around 9.5 and think you can add h.p. just by cleaning up the rough edges of the original heads and adding you MAGIC Lunati cam and you think you can get 375 h.p. (not with the things you have stated you are going to do. The only way you are going to get close to that is with headers, head porting and an aggressive cam OR to stroke the engine for more cubes.) out of it. Sounds to me like a pipe dream and if this is what your machinist is telling you I would find a new one. I assume you want to drop the compression so you can run the car on pump gas without timing detonation which is a common goal these days. If you drop the compression with the original cast iron heads you can do that but will loose power. Everything has to work together to accomplish what you want. The way to increase power in your engine is with more or more efficent air flow through the heads and the only way to do that is to port them. (your plans to "clean up the rough edges" in the heads is a waste of money as you will see no performance gain from this) The cost of doing that to your original heads is not far from the cost of aluminum heads. The other alternative is to buy new aluminum heads that are already designed for the better flow. Regarding the original look you can buy the Trick Flow heads with the double hump marking and paint them engine color and 99% of the lookers will never know they are not original. BTW, the aluminum heads dissipate the heat better and will allow you to run up to 11 to 1 compression (like your original engine) on pump gas. With the heads breathing better you can now pump more air/fuel through the engine but added power will be effected by the limits of your 2.5” exhaust manifolds. You can port match the exhaust and intake manifolds for some gain but then to really make a difference you will likely need a little more fuel. BTW, you can not increase the cfm rating of your carb as you eluded to previously but you can re-jet the carb for different air fuel mixture. The only way you can increase the cfm is by switching to a larger cfm carb. However I don’t believe you really need any more cfm and you stock carb should be fine. Now we are on to the cam. Aftermarket type cams other than OEM type grinds are ALL designed for the use of headers. OTOH, OEM cams designed by the factory are for use with factory exhaust manifolds and are hard to beat with the factory manifolds and often out perform the aftermarket cams unless you use headers with them. You said you want a somewhat stock sound which in the case of your engine is a little lumpy cam and the sound of the solid lifters. All of this being said if you car is drivable now I would drive it a little and see if the engine performs to your liking. If so and you want to be able to run on pump gas then I would do a stock BALANCED rebuild (including stock 340 h.p. cam but use aftermarket rods as the factory ones are the weak part of the lower end of the small block) and add the aluminum heads with the factory compression. Then you can run pump gas and with those heads, good tune including distributor tweaking you will likely be at the 375+ h.p. you want.
OK, I have read all of your posts in the threads you have going on and am going to respond to what I believe is your goal for this car and with where your thinking is flawed.
First of all you need to determine how you are going to use the car. Is it going to be an around town car with occasional short freeway trips or are you going to use it primarily on the freeway? Most of us use our cars as the first option and if that is you as well you really can’t go wrong with the way you car was configured from the factory. I would not be concerned with gas mileage since you likely will not put that many miles on the car annually.
You want to switch to a higher speed rear end ratio I assume for either better mileage and or less high rpm engine wear on the highway. You believe that the original rear axle ratio is a 4.11 per the tag marking on the rear end. I don’t believe you could get a non posi 4.11 in a Corvette from the factory so if you have checked it correctly then likely the posi is worn out.
The factory combination of your original 340 h.p. and the 4.11 gears is pretty much the best performance combination available from the factory in 1962 (especially with the 4.11s) other than an FI car.
I know you have mentioned that you don’t want to spend a lot of money on this car and want to keep it as original looking as possible. I think that means no headers, stock carb and manifolds etc. Nothing is cheap these days and if you want your 57 year old car dependable then you need to spend the money required to make the engine as such.
You want to increase h.p. by cutting compression to around 9.5 and think you can add h.p. just by cleaning up the rough edges of the original heads and adding you MAGIC Lunati cam and you think you can get 375 h.p. (not with the things you have stated you are going to do. The only way you are going to get close to that is with headers, head porting and an aggressive cam OR to stroke the engine for more cubes.) out of it. Sounds to me like a pipe dream and if this is what your machinist is telling you I would find a new one. I assume you want to drop the compression so you can run the car on pump gas without timing detonation which is a common goal these days. If you drop the compression with the original cast iron heads you can do that but will loose power. Everything has to work together to accomplish what you want. The way to increase power in your engine is with more or more efficent air flow through the heads and the only way to do that is to port them. (your plans to "clean up the rough edges" in the heads is a waste of money as you will see no performance gain from this) The cost of doing that to your original heads is not far from the cost of aluminum heads. The other alternative is to buy new aluminum heads that are already designed for the better flow. Regarding the original look you can buy the Trick Flow heads with the double hump marking and paint them engine color and 99% of the lookers will never know they are not original. BTW, the aluminum heads dissipate the heat better and will allow you to run up to 11 to 1 compression (like your original engine) on pump gas. With the heads breathing better you can now pump more air/fuel through the engine but added power will be effected by the limits of your 2.5” exhaust manifolds. You can port match the exhaust and intake manifolds for some gain but then to really make a difference you will likely need a little more fuel. BTW, you can not increase the cfm rating of your carb as you eluded to previously but you can re-jet the carb for different air fuel mixture. The only way you can increase the cfm is by switching to a larger cfm carb. However I don’t believe you really need any more cfm and you stock carb should be fine. Now we are on to the cam. Aftermarket type cams other than OEM type grinds are ALL designed for the use of headers. OTOH, OEM cams designed by the factory are for use with factory exhaust manifolds and are hard to beat with the factory manifolds and often out perform the aftermarket cams unless you use headers with them. You said you want a somewhat stock sound which in the case of your engine is a little lumpy cam and the sound of the solid lifters. All of this being said if you car is drivable now I would drive it a little and see if the engine performs to your liking. If so and you want to be able to run on pump gas then I would do a stock BALANCED rebuild (including stock 340 h.p. cam but use aftermarket rods as the factory ones are the weak part of the lower end of the small block) and add the aluminum heads with the factory compression. Then you can run pump gas and with those heads, good tune including distributor tweaking you will likely be at the 375+ h.p. you want.
Last edited by 68hemi; Dec 27, 2018 at 11:04 PM.
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You are probably tired of hearing me say this over and over but I can't stress how important it is to do thing RIGHT the first time rather than later when you car is not performing the way you hoped it would you have to go back into the engine and do it over again. Below is a copy and paste that I posted in one of you threads in the past that I think you should re-read. I have bolded some area that are of particular importance. I have also added some NEW info below in parentheses and bolded for your review.
OK, I have read all of your posts in the threads you have going on and am going to respond to what I believe is your goal for this car and with where your thinking is flawed.
First of all you need to determine how you are going to use the car. Is it going to be an around town car with occasional short freeway trips or are you going to use it primarily on the freeway? Most of us use our cars as the first option and if that is you as well you really can’t go wrong with the way you car was configured from the factory. I would not be concerned with gas mileage since you likely will not put that many miles on the car annually.
You want to switch to a higher speed rear end ratio I assume for either better mileage and or less high rpm engine wear on the highway. You believe that the original rear axle ratio is a 4.11 per the tag marking on the rear end. I don’t believe you could get a non posi 4.11 in a Corvette from the factory so if you have checked it correctly then likely the posi is worn out.
The factory combination of your original 340 h.p. and the 4.11 gears is pretty much the best performance combination available from the factory in 1962 (especially with the 4.11s) other than an FI car.
I know you have mentioned that you don’t want to spend a lot of money on this car and want to keep it as original looking as possible. I think that means no headers, stock carb and manifolds etc. Nothing is cheap these days and if you want your 57 year old car dependable then you need to spend the money required to make the engine as such.
You want to increase h.p. by cutting compression to around 9.5 and think you can add h.p. just by cleaning up the rough edges of the original heads and adding you MAGIC Lunati cam and you think you can get 375 h.p. (not with the things you have stated you are going to do. The only way you are going to get close to that is with headers, head porting and an aggressive cam OR to stroke the engine for more cubes.) out of it. Sounds to me like a pipe dream and if this is what your machinist is telling you I would find a new one. I assume you want to drop the compression so you can run the car on pump gas without timing detonation which is a common goal these days. If you drop the compression with the original cast iron heads you can do that but will loose power. Everything has to work together to accomplish what you want. The way to increase power in your engine is with more or more efficent air flow through the heads and the only way to do that is to port them. (your plans to "clean up the rough edges" in the heads is a waste of money as you will see no performance gain from this) The cost of doing that to your original heads is not far from the cost of aluminum heads. The other alternative is to buy new aluminum heads that are already designed for the better flow. Regarding the original look you can buy the Trick Flow heads with the double hump marking and paint them engine color and 99% of the lookers will never know they are not original. BTW, the aluminum heads dissipate the heat better and will allow you to run up to 11 to 1 compression (like your original engine) on pump gas. With the heads breathing better you can now pump more air/fuel through the engine but added power will be effected by the limits of your 2.5” exhaust manifolds. You can port match the exhaust and intake manifolds for some gain but then to really make a difference you will likely need a little more fuel. BTW, you can not increase the cfm rating of your carb as you eluded to previously but you can re-jet the carb for different air fuel mixture. The only way you can increase the cfm is by switching to a larger cfm carb. However I don’t believe you really need any more cfm and you stock carb should be fine. Now we are on to the cam. Aftermarket type cams other than OEM type grinds are ALL designed for the use of headers. OTOH, OEM cams designed by the factory are for use with factory exhaust manifolds and are hard to beat with the factory manifolds and often out perform the aftermarket cams unless you use headers with them. You said you want a somewhat stock sound which in the case of your engine is a little lumpy cam and the sound of the solid lifters. All of this being said if you car is drivable now I would drive it a little and see if the engine performs to your liking. If so and you want to be able to run on pump gas then I would do a stock BALANCED rebuild (including stock 340 h.p. cam but use aftermarket rods as the factory ones are the weak part of the lower end of the small block) and add the aluminum heads with the factory compression. Then you can run pump gas and with those heads, good tune including distributor tweaking you will likely be at the 375+ h.p. you want.
OK, I have read all of your posts in the threads you have going on and am going to respond to what I believe is your goal for this car and with where your thinking is flawed.
First of all you need to determine how you are going to use the car. Is it going to be an around town car with occasional short freeway trips or are you going to use it primarily on the freeway? Most of us use our cars as the first option and if that is you as well you really can’t go wrong with the way you car was configured from the factory. I would not be concerned with gas mileage since you likely will not put that many miles on the car annually.
You want to switch to a higher speed rear end ratio I assume for either better mileage and or less high rpm engine wear on the highway. You believe that the original rear axle ratio is a 4.11 per the tag marking on the rear end. I don’t believe you could get a non posi 4.11 in a Corvette from the factory so if you have checked it correctly then likely the posi is worn out.
The factory combination of your original 340 h.p. and the 4.11 gears is pretty much the best performance combination available from the factory in 1962 (especially with the 4.11s) other than an FI car.
I know you have mentioned that you don’t want to spend a lot of money on this car and want to keep it as original looking as possible. I think that means no headers, stock carb and manifolds etc. Nothing is cheap these days and if you want your 57 year old car dependable then you need to spend the money required to make the engine as such.
You want to increase h.p. by cutting compression to around 9.5 and think you can add h.p. just by cleaning up the rough edges of the original heads and adding you MAGIC Lunati cam and you think you can get 375 h.p. (not with the things you have stated you are going to do. The only way you are going to get close to that is with headers, head porting and an aggressive cam OR to stroke the engine for more cubes.) out of it. Sounds to me like a pipe dream and if this is what your machinist is telling you I would find a new one. I assume you want to drop the compression so you can run the car on pump gas without timing detonation which is a common goal these days. If you drop the compression with the original cast iron heads you can do that but will loose power. Everything has to work together to accomplish what you want. The way to increase power in your engine is with more or more efficent air flow through the heads and the only way to do that is to port them. (your plans to "clean up the rough edges" in the heads is a waste of money as you will see no performance gain from this) The cost of doing that to your original heads is not far from the cost of aluminum heads. The other alternative is to buy new aluminum heads that are already designed for the better flow. Regarding the original look you can buy the Trick Flow heads with the double hump marking and paint them engine color and 99% of the lookers will never know they are not original. BTW, the aluminum heads dissipate the heat better and will allow you to run up to 11 to 1 compression (like your original engine) on pump gas. With the heads breathing better you can now pump more air/fuel through the engine but added power will be effected by the limits of your 2.5” exhaust manifolds. You can port match the exhaust and intake manifolds for some gain but then to really make a difference you will likely need a little more fuel. BTW, you can not increase the cfm rating of your carb as you eluded to previously but you can re-jet the carb for different air fuel mixture. The only way you can increase the cfm is by switching to a larger cfm carb. However I don’t believe you really need any more cfm and you stock carb should be fine. Now we are on to the cam. Aftermarket type cams other than OEM type grinds are ALL designed for the use of headers. OTOH, OEM cams designed by the factory are for use with factory exhaust manifolds and are hard to beat with the factory manifolds and often out perform the aftermarket cams unless you use headers with them. You said you want a somewhat stock sound which in the case of your engine is a little lumpy cam and the sound of the solid lifters. All of this being said if you car is drivable now I would drive it a little and see if the engine performs to your liking. If so and you want to be able to run on pump gas then I would do a stock BALANCED rebuild (including stock 340 h.p. cam but use aftermarket rods as the factory ones are the weak part of the lower end of the small block) and add the aluminum heads with the factory compression. Then you can run pump gas and with those heads, good tune including distributor tweaking you will likely be at the 375+ h.p. you want.
DON'T know why you are claiming the OP stated he was looking to achieve 375+hp.... "Then you can run pump gas and with those heads, good tune including distributor tweaking you will likely be at the 375+ h.p. you want".
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From: Cottonwood AZ
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The OP ( 6T2Vette) stated in his initial post that he wanted to achieve at least 1 horsepower per cubic inch of displacement...327 Cubic Inch = 327 Horsepower.
DON'T know why you are claiming the OP stated he was looking to achieve 375+hp.... "Then you can run pump gas and with those heads, good tune including distributor tweaking you will likely be at the 375+ h.p. you want".
DON'T know why you are claiming the OP stated he was looking to achieve 375+hp.... "Then you can run pump gas and with those heads, good tune including distributor tweaking you will likely be at the 375+ h.p. you want".
If you go back to the original thread that my information comes from you will see that he said he wanted 375 horse power. He may have change that later on but I was addressing the post that he asked for 375 hp
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JIM
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In order to accomplish that, I would need modern heads, a different cam, and a more sophisticated exhaust header system. NOT WHAT I WANT!!!
I'm willing to concede 50 horsepower if I can keep my original heads, headers, and carburetor. The new cam will take all of these changes into consideration. It is being ground to complement the new compression and carburation, and improving airflow and exhaust. All this using regular unleaded gas. :-)
Bob
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Bob
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From: Monrovia MD
That's strong lift on a short duration cam with a 109 LSA Would build good cylinder pressure and be responsive...but it's going to be done by 4800-5000 or so max. Even the old Comp 268H had more duration and it's pretty mild.
JIM
JIM
The Voodoo roller cam more comparable to 268h would be the 20120711, or maybe the 20120712.
OP, I just ran some simulations using the Voodoo 20120710 cam. With a 327, pocket ported heads and a 660 carb, it’s at 303 hp running through stock exhaust manifolds and mufflers. And 361 hp with open long tube headers. Hp peak is at ~5000 rpm.
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Actually, the LSA on that cam is 112. And the high lift is due to it being a hydraulic roller cam. It’s a low end cam, but does have good power to mid 5000s. It’s meant to be the roller equivalent to 262 cams out there. Here’s a link to the specs... http://www.lunatipower.com/Product.aspx?id=1987.
The Voodoo roller cam more comparable to 268h would be the 20120711, or maybe the 20120712.
OP, I just ran some simulations using the Voodoo 20120710 cam. With a 327, pocket ported heads and a 660 carb, it’s at 303 hp running through stock exhaust manifolds and mufflers. And 361 hp with open long tube headers. Hp peak is at ~5000 rpm.
JIM
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HP is function of torque AND RPM.
The Tq/HP curves cross at 5250 RPM. (SWDuke had a very explanation of why that is, with math, for those so inclined, a while back).
Your torque is basically a function of your compression ratio and displacement. An 11:1 motor will have ~20% more tq than 9:1 CR motor, no matter what cam in in it, the cam selection just moves the Tq curve around*. You will never, can never have higher HP than Tq below 5250 RPM, so if you want 375 HP, you will need 11;1 CR (or close), AND be able to turn past 6000 RPM without the Tq falling off a cliff. Torgue curves on a well built "streetable" motor should be fairly flat with drop offs towards idle,and also at the opposite end where breathing can't keep up with RPM. An 11:1 motor will also have about 20% more HP than a 9:1 motor at any particular RPM.
If your Tq curve starts falling off around 5000 RPM, you will not get high HP numbers, but Torque, at low RPM is what makes a fun street car.
*A roller cam can broaden the Tq curve considerable due to higher faster lift and more gross area under the lift curve
Doug
The Tq/HP curves cross at 5250 RPM. (SWDuke had a very explanation of why that is, with math, for those so inclined, a while back).
Your torque is basically a function of your compression ratio and displacement. An 11:1 motor will have ~20% more tq than 9:1 CR motor, no matter what cam in in it, the cam selection just moves the Tq curve around*. You will never, can never have higher HP than Tq below 5250 RPM, so if you want 375 HP, you will need 11;1 CR (or close), AND be able to turn past 6000 RPM without the Tq falling off a cliff. Torgue curves on a well built "streetable" motor should be fairly flat with drop offs towards idle,and also at the opposite end where breathing can't keep up with RPM. An 11:1 motor will also have about 20% more HP than a 9:1 motor at any particular RPM.
If your Tq curve starts falling off around 5000 RPM, you will not get high HP numbers, but Torque, at low RPM is what makes a fun street car.
*A roller cam can broaden the Tq curve considerable due to higher faster lift and more gross area under the lift curve
Doug
Last edited by AZDoug; Dec 28, 2018 at 12:03 PM.
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Actually, the LSA on that cam is 112. And the high lift is due to it being a hydraulic roller cam. It’s a low end cam, but does have good power to mid 5000s. It’s meant to be the roller equivalent to 262 cams out there. Here’s a link to the specs... http://www.lunatipower.com/Product.aspx?id=1987.
The Voodoo roller cam more comparable to 268h would be the 20120711, or maybe the 20120712.
OP, I just ran some simulations using the Voodoo 20120710 cam. With a 327, pocket ported heads and a 660 carb, it’s at 303 hp running through stock exhaust manifolds and mufflers. And 361 hp with open long tube headers. Hp peak is at ~5000 rpm.
Last edited by 6T2Vette; Dec 28, 2018 at 12:42 PM.
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From: Monrovia MD
My machinist was estimating about 290hp-300hp. I told him 290 was too low, so he recommended dumping the voodoo and going with a custom ground cam. We agreed on a cam that will give me one hp per ci. I don’t have the knowledge to calculate what this will do for me but I know it should be fun.
I ran a number different simulations this morning playing with cam specs and flow numbers for the head. Looks like pocket porting the heads would make a huge difference for your intended build. Using the Voodoo cam, I’m seeing a 35hp difference between stock heads and heads with just pocket porting. So whichever cam you decide on, give some thought to a little bit of porting.
Once you have it up and running, please post results.
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Sounds like your machinists and the simulation software are in agreement. Good to see that.
I ran a number different simulations this morning playing with cam specs and flow numbers for the head. Looks like pocket porting the heads would make a huge difference for your intended build. Using the Voodoo cam, I’m seeing a 35hp difference between stock heads and heads with just pocket porting. So whichever cam you decide on, give some thought to a little bit of porting.
Once you have it up and running, please post results.
Pro
Joined: Feb 2013
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From: San Francisco Bay Area Ca
Depending upon whether you are going to pursue running a relatively "low" compression ratio of 9:1 vs 11:1.
MANY modern engines are running 11:1 compression ratio on High Test Gas (92.1) here in California....HaveTO LAUGH as I remember as a teenage driver in the 70s....Texaco had 105 Octane gas from the pump...with LEAD!!!
.....might account for some ( MANY) of my personality traits 
Click on the link below and you will SEE/READ....the myriad of Sports Cars/Cars that are having compression ratios where 11:1 is COMMON!!!.....and as HIGH as 12:7 as evidenced by the Lamborghini
Proven calculations have demonstrated that Increasing the compression ratio from 9:1 to 11:1 is a possible horsepower IMPROVEMENT of approximately 8% ( AS a 1% increase in compression ratio is worth 3-4 %)...
Excerpt from the link below.... "The generally accepted gauge for adding compression is that one full point of compression can add between 3 to 4 percent power. So, if an engine is making 50 horsepower and we add a full point of compression (from 11 to 12:1 for example), this could potentially push the power to 51.5 horsepower.".......
http://blog.jepistons.com/compressio...in-powersports .
in my engine building book...8% per 100 horsepower ...meaning a 300 horsepower engine at 9:1 compression ratio....just Increased to 324 Horsepower at 11:1 compression ratio !!!... just from increasing the compression ratio is HUGE!!!....and a NO BRAINIER ( Not meant to disparage 6T2Vette)....
If going to the expensive of the machine work and parts you have already listed for relatively marginal horsepower gains....
WHY give up 8% of potential horsepower gain by NOT increasing the compression ratio....
The few extra $$$ you have to pay at the pump for the higher grade gasoline....is minuscule in comparison to the horsepower you are LOSING!!!
For your own edification ( and I'm Curious as well as probably others are)... Do the engine computer horsepower simulation using the 9:1 compression ratio vs the 11:1 compression ratio.
My experience tells me the increased compression ratio ( 11:1) will garner you the greatest horsepower increase vs any other engine component/s....part/s that you are planning to build your engine with!.....Mark
https://www.google.com/search?q=2018+lamborghini+huracan+compre ssion+ratio&stick=H4sIAAAAAAAAAONgFuLVT9 c3NEzPKo8vKTE1V4JyU3IqK83Nq7REnBOLfPNTUn MiUxOLgjNTUssTK4sXMWpnJ1vpJ5aW5Ofml2SWpe rngpTEVwLVWCXn5xYUpRYXZ-bnxRcllmTmAwCKDqEyZAAAAA&sa=X&ved=2ahUKE wjqyPCD38PfAhXwHjQIHTdSAz8QxA0wA3oECAgQD g&biw=1280&bih=581
MANY modern engines are running 11:1 compression ratio on High Test Gas (92.1) here in California....HaveTO LAUGH as I remember as a teenage driver in the 70s....Texaco had 105 Octane gas from the pump...with LEAD!!!
.....might account for some ( MANY) of my personality traits Click on the link below and you will SEE/READ....the myriad of Sports Cars/Cars that are having compression ratios where 11:1 is COMMON!!!.....and as HIGH as 12:7 as evidenced by the Lamborghini
Proven calculations have demonstrated that Increasing the compression ratio from 9:1 to 11:1 is a possible horsepower IMPROVEMENT of approximately 8% ( AS a 1% increase in compression ratio is worth 3-4 %)...
Excerpt from the link below.... "The generally accepted gauge for adding compression is that one full point of compression can add between 3 to 4 percent power. So, if an engine is making 50 horsepower and we add a full point of compression (from 11 to 12:1 for example), this could potentially push the power to 51.5 horsepower.".......
http://blog.jepistons.com/compressio...in-powersports .
in my engine building book...8% per 100 horsepower ...meaning a 300 horsepower engine at 9:1 compression ratio....just Increased to 324 Horsepower at 11:1 compression ratio !!!... just from increasing the compression ratio is HUGE!!!....and a NO BRAINIER ( Not meant to disparage 6T2Vette)....
If going to the expensive of the machine work and parts you have already listed for relatively marginal horsepower gains....
WHY give up 8% of potential horsepower gain by NOT increasing the compression ratio....
The few extra $$$ you have to pay at the pump for the higher grade gasoline....is minuscule in comparison to the horsepower you are LOSING!!!
For your own edification ( and I'm Curious as well as probably others are)... Do the engine computer horsepower simulation using the 9:1 compression ratio vs the 11:1 compression ratio.
My experience tells me the increased compression ratio ( 11:1) will garner you the greatest horsepower increase vs any other engine component/s....part/s that you are planning to build your engine with!.....Mark
https://www.google.com/search?q=2018+lamborghini+huracan+compre ssion+ratio&stick=H4sIAAAAAAAAAONgFuLVT9 c3NEzPKo8vKTE1V4JyU3IqK83Nq7REnBOLfPNTUn MiUxOLgjNTUssTK4sXMWpnJ1vpJ5aW5Ofml2SWpe rngpTEVwLVWCXn5xYUpRYXZ-bnxRcllmTmAwCKDqEyZAAAAA&sa=X&ved=2ahUKE wjqyPCD38PfAhXwHjQIHTdSAz8QxA0wA3oECAgQD g&biw=1280&bih=581
Last edited by sidepipe seeker; Dec 28, 2018 at 07:47 PM.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Added details to help heads flow are larger valves with tulip intakes, contoured and polished chambers. Pocket porting is the next best thing to full runner porting and a good idea for the money spent.
IMHO I think an owner should try as many performance tricks as he can while still having fun with it. Working with a good machine shop helps but don't expect added labor to be free. But when the fun stops or the work becomes to expensive it's a good indicator to become more realistic with your goals. After all what you end up with is what you really wanted to do for yourself and it will be what it is. That said I would focus on the bottom end of the block as changing cylinder heads and everything above them can be done with the engine in the car.
Good luck and hope this can help.
BTW my cam now is Schneider solid lifter cam - the smallest solid lifter cam they make (and possibly anyone makes).
Pro
Joined: Oct 2013
Posts: 629
Likes: 126
From: Grapevine TX
IMHO, C/R is meaningless without taking into consideration the inlet valve closing point and Dynamic C/R. I'm sure most everyone here is very familiar with all this camshaft and HP stuff, But here is a good link that simplifies things.
https://www.chevydiy.com/chevy-small...d-valvetrains/
https://www.chevydiy.com/chevy-small...d-valvetrains/
Team Owner
Joined: Nov 2005
Posts: 28,223
Likes: 2,872
From: Beach & High Desert Southern California
The Voodoo cam was too mild in duration, a good attribute for early speed density fuel injection systems that needs a stable idle vacuum signal, but a carb system is more forgiving and can tolerate a longer duration cam. You made a good choice to try something from a cam grinder who is local to the machine shop. Schneider has cut a lot of competitive cams. Are you still going with a hydraulic roller cam & lifters?