Will this be enough valve spring pressure to turn 7000 rpm?

[fastblackracing]

The new setup will be champion gn1 heads comp roller cam, comp solid rollers. scorpian 1.6 rockers and comp valve spring # 917 which will be 200# seat pressure 511# open. with titanium retainers. this is a little 233inc motor so i need to turn it a bit. cam lobes are intake -3119 hi-lift .560lift 224*duration /exhaust is lobe-3312 .520 lift 212*duration. I have room to add another 30-60 # of spring pressure if needed. also what would be the best pushrod for this, looks like it gonna need a 9.200x5/16 since its so long i am concerned about flex and harmonics. Also looking for a nice set of t&D shaft set up thanks for your input <Mannie​

 

[FASTV6HENRY]

Mannie.....At 200lbs of seat pressure you will have enough to spin it to 7,000. However i dont think you will need to turn the motor to 7,000rpm with a 212 @.50 i think the area under the power curve for that cam is from 1,500-6,500.

 

[BEATAV8]

check your rocker stands....
http://turbobuick.com/forums/threads/broken-gn1-rocker-stand.386992/page-3#post-3120257

7000rpm is really high. unless you plan to trap around 155mph, or your torque converter is way too loose and slipping a lot.

 

[lazaris]

The new setup will be champion gn1 heads comp roller cam, comp solid rollers. scorpian 1.6 rockers and comp valve spring # 917 which will be 200# seat pressure 511# open. with titanium retainers. this is a little 233inc motor so i need to turn it a bit. cam lobes are intake -3119 hi-lift .560lift 224*duration /exhaust is lobe-3312 .520 lift 212*duration. I have room to add another 30-60 # of spring pressure if needed. also what would be the best pushrod for this, looks like it gonna need a 9.200x5/16 since its so long i am concerned about flex and harmonics. Also looking for a nice set of t&D shaft set up thanks for your input <Mannie​

Not enough seat pressure for 7000. The boost pressure and back pressure play a roll as well. If it were me I'd add the 60lbs to it. I would also clearance the head and ad a 3/8 .120 wall pushrod.

 

[750H.P.V6]

Mannie,

The motor will run out of wind way before 7000 RPM with that cam. I'd be surprised if it made power above 6300 RPM. With that being said the springs should work fine. I agree with what Ralph said in regard to the 3/8" pushrods.

Neal

 

[lazaris]

Mannie,

The motor will run out of wind way before 7000 RPM with that cam. I'd be surprised if it made power above 6300 RPM. With that being said the springs should work fine. I agree with what Ralph said in regard to the 3/8" pushrods.

Neal

Neal I was just commenting on the 7000 rpm threshold that someone brought up. Which I feel is not enough spring pressure for that rpm. As far as the cam, I agree It will be done before 7000 rpm. Dont forget if thats a new spring it will loose some pressure right off the bat after a few passes which will put it below 200lbs. I still would like to see a bit more to start off with.

 

[bison]

Those lobes won't go anywhere near 7000 especially on a Buick cam core even with a tight lashed solid lifter. Also the valves can't be the standard valves used in GN1's. You won't have enough room to get the installed height were you need it without hitting coil bind if you need a 7000rpm valvetrain.

 

[turbobitt]

I think the 200# would be enough. I ran 180# with heavy stage 2 valve train for years with no problems. When I dynoed the car it only had 225# at the seat. Now with my new cam I have about 270#. Like stated, backpressure may also come into play though.
As far as the 7000 RPM mark I think the cam will be done way before that.

Allan G.

 

[Nick Micale]

I can easily run over 7000 RPM with 190# on the seat, and do it more times than I like.

Your Chevy-style rockers would be more of a concern than the cam at 7K, even though you are probably past the power band? My paired Jessel-style rockers are much more stable, and the geometry is excellent, unlike the Scorpions on a Buick head?

My pushrods have always been 5/16" thick wall, and never had any issue with them.

 

[fastblackracing]

The new setup will be champion gn1 heads comp roller cam, comp solid rollers. scorpian 1.6 rockers and comp valve spring # 917 which will be 200# seat pressure 511# open. with titanium retainers. this is a little 233inc motor so i need to turn it a bit. cam lobes are intake -3119 hi-lift .560lift 224*duration /exhaust is lobe-3312 .520 lift 212*duration. I have room to add another 30-60 # of spring pressure if needed. also what would be the best pushrod for this, looks like it gonna need a 9.200x5/16 since its so long i am concerned about flex and harmonics. Also looking for a nice set of t&D shaft set up thanks for your input <Mannie​

What I am looking for is to be able to make usable power to 6500-6600 and have enough spring to go a few hundered over that if it happens. The geometry with an adjustable pushrod set at 9.200 is well centered and the roller sweep measures .070. Nick are the thickwall pushrods your talking about the.080 or .125 wall thickness?.

 

[bison]

I'd be using a completely different cam if I
wanted to make useful power to 6500. It would need quite a bit of turbo also.

 

[750H.P.V6]

Neal I was just commenting on the 7000 rpm threshold that someone brought up. Which I feel is not enough spring pressure for that rpm. As far as the cam, I agree It will be done before 7000 rpm. Dont forget if thats a new spring it will loose some pressure right off the bat after a few passes which will put it below 200lbs. I still would like to see a bit more to start off with.

Ralph,

I'm there with you. If the cam would be good for 7000 RPM the spring seat pressure and over the nose might be a little less than optimal once you take into consideration the loss you typically see once the springs are used vs new. The limiting factor at this point is the cam selection and not the springs.

Neal

 

[fastblackracing]

I'd be using a completely different cam if I
wanted to make useful power to 6500. It would need quite a bit of turbo also.

I am going to run this cam since I already have it, I used it in a bigger motor that ran well to 6000. But what lobes and spring pressures would you recomend for this Bison? looking to end up with enough power to go 140-145 mph, heads are nicely ported and compression is 8.6. It is also non-lockup converter. Thanks for every ones input.

 

[bison]

I am going to run this cam since I already have it, I used it in a bigger motor that ran well to 6000. But what lobes and spring pressures would you recomend for this Bison? looking to end up with enough power to go 140-145 mph, heads are nicely ported and compression is 8.6. It is also non-lockup converter. Thanks for every ones input.

The CR is a little low for optimization but I'd use hyd lobes 3014 and 3034, 110LS on a billet cam. 200 on the seat is fine with 885 lifters. Ive ran this cam and last time I ran the car it trapped 138+ on 93/alky @25psi. Peak power is at 5600 and it holds within 20hp of peak power past 6000. At 28-29psi in good air it would be enough to run 142-143. If you arent worried about spooling fast. On the strip you could run a larger intake lobe and raise the power band a little. The trade off will be a little more overlap. You need really good heads and enough turbo to support the mass flow and the converter has to be able to couple it or the cam won't matter. keep in mind the duration @.050 doesnt tell you much. Look at the duration @.200" and compare the different lobe families. You can see why some families of lobes will make more power and reduce overlap over other families. You need overlap or you won't make power but there is definitely room for improvement over the standard stuff you commonly see run on these forums. You might also consider running a higher rocker ratio to get some of the intensity back. I did and if you have the springs right you will pick up power.

 

[qws2000]

How do you find out this info on your cams/valves/springs.... My car is stuck at 5600 rpm and then fall on its face???

 

[lazaris]

I think the 200# would be enough. I ran 180# with heavy stage 2 valve train for years with no problems. When I dynoed the car it only had 225# at the seat. Now with my new cam I have about 270#. Like stated, backpressure may also come into play though.
As far as the 7000 RPM mark I think the cam will be done way before that.

Allan G.

Allan did you ever try running more spring and push rod with that original combination ?

 

[lazaris]

I can easily run over 7000 RPM with 190# on the seat, and do it more times than I like.

Your Chevy-style rockers would be more of a concern than the cam at 7K, even though you are probably past the power band? My paired Jessel-style rockers are much more stable, and the geometry is excellent, unlike the Scorpions on a Buick head?

My pushrods have always been 5/16" thick wall, and never had any issue with them.

Nick, did you ever try running more spring and push rod with that original combination ?

 

[turbobitt]

Allan did you ever try running more spring and push rod with that original combination ?

My original cam was initially run using the 180#(actually rated at 176#) springs and was able to meet my initial goal of running in the 9's. I never dynoed the engine at that point. Afer running it on the street for about 10 years I decided to tear down and inspect the springs and freshen the engine. Found that the springs ranged from 168-174# after 10 years of street beating/driving and a hand full of runs. I gave in to peer pressure from everyone telling me that I needed more spring so I stepped up to 225# springs. This is still with the same cam and 3/8 x .080 wall pushrods. this is when I put the car on a chasis dyno.
Afrer the dyno, I decided to change the cam to something I thought was more favorable for my combination. I again stepped up the spring load but kept the same pushrods. This is how I ran the car and made my first 8 second pass. Did not go back on the dyno.
Now fast forward to taday, I'm working on a new cam change and plan on changing the pushrods to a single or dual tapper style. They tend to be stiffer than a straight pushrod. Since I'm not working on many other things on the car at the same time I have a little more funds to make these changes. I havn't decided if I'm going to a different spring yet.
My current pushrod size concerns me a little. I don't have any problems with bent tubes but that doesn't stop them from becoming big springs under high RPM. The tappered pushrods will eliminate any concerns.
Allan G.

 

[fastblackracing]

My original cam was initially run using the 180#(actually rated at 176#) springs and was able to meet my initial goal of running in the 9's. I never dynoed the engine at that point. Afer running it on the street for about 10 years I decided to tear down and inspect the springs and freshen the engine. Found that the springs ranged from 168-174# after 10 years of street beating/driving and a hand full of runs. I gave in to peer pressure from everyone telling me that I needed more spring so I stepped up to 225# springs. This is still with the same cam and 3/8 x .080 wall pushrods. this is when I put the car on a chasis dyno.
Afrer the dyno, I decided to change the cam to something I thought was more favorable for my combination. I again stepped up the spring load but kept the same pushrods. This is how I ran the car and made my first 8 second pass. Did not go back on the dyno.
Now fast forward to taday, I'm working on a new cam change and plan on changing the pushrods to a single or dual tapper style. They tend to be stiffer than a straight pushrod. Since I'm not working on many other things on the car at the same time I have a little more funds to make these changes. I havn't decided if I'm going to a different spring yet.
My current pushrod size concerns me a little. I don't have any problems with bent tubes but that doesn't stop them from becoming big springs under high RPM. The tappered pushrods will eliminate any concerns.
Allan G.

Thanks for the info, I am going to run the 917 springs and install them at 230#.

 

[fastblackracing]

The CR is a little low for optimization but I'd use hyd lobes 3014 and 3034, 110LS on a billet cam. 200 on the seat is fine with 885 lifters. Ive ran this cam and last time I ran the car it trapped 138+ on 93/alky @25psi. Peak power is at 5600 and it holds within 20hp of peak power past 6000. At 28-29psi in good air it would be enough to run 142-143. If you arent worried about spooling fast. On the strip you could run a larger intake lobe and raise the power band a little. The trade off will be a little more overlap. You need really good heads and enough turbo to support the mass flow and the converter has to be able to couple it or the cam won't matter. keep in mind the duration @.050 doesnt tell you much. Look at the duration @.200" and compare the different lobe families. You can see why some families of lobes will make more power and reduce overlap over other families. You need overlap or you won't make power but there is definitely room for improvement over the standard stuff you commonly see run on these forums. You might also consider running a higher rocker ratio to get some of the intensity back. I did and if you have the springs right you will pick up power.

I see what your getting at bison, I am not sure if those lobes were out when I had that one made. Thanks for your input.