Valve Spring Requirement w/ 40 PSI & Boost???

[BlownV6]

Valve Spring Requirement w/ 40 PSI Boost???

Looking for Advice! I have a 274 with Stage II Heads, Titatium Valves, 280 Deg Durration @ .050, 782 lift, Roots Style Kobelco Hi-Helix Blower on alcohol. Problem is it only makes about 850 HP and stops pulling around 6800 RPM. Seat pressure is around 260# with open @ 750#? This is all fairly new combination and I'm looking for answers to the problem! What kind of seat pressure do I NEED??? This set up is in a dragster 1500# .999-60', 2.80-330', 4.49-660' Looking for 3.90!


Thanks, Mike

 

[Lee Thompson]

picture

Saw the picture of you and your hotrod in National Dragster. Are you bringing it to B.G. this spring? Very few people know about your V-6 dragster. Sorry, can/t help with your ?

 

[HighPSI]

I have a customer with a twin turbo stage2 dragster that will be bringing it to BG. It would be nice if there was another one there.

 

[BlownV6]

Bowling Green Nationals

Lee & Cal,
Reference Bowling Green Nationals, definately would like to bring my car, but I am not sure if they will let me race. Also, I am changing alot of things on the engine and building a new house in the spring, so I am not 100% sure it will be running. Looking at switching to ODD FIRE. Thanks, Mike

 

[Buzzard]

If it has a Buick motor you can run it in Bowling Green.
I will make sure that if you plan on coming that you will get a great track to race on. I think a shoot out between two dragsters would be a neat exhibition race. Hope to see you there.

 

[BlownV6]

Bowling Green

Is there a chance we could enter quick 16 ???? What is minium dial in bracket race ?

 

[turbolou]

Re: Valve Spring Requirement w/ 40 PSI Boost???

Originally posted by BlownV6
Looking for Advice! I have a 274 with Stage II Heads, Titatium Valves, 280 Deg Durration @ .050, 782 lift, Roots Style Kobelco Hi-Helix Blower on alcohol. Problem is it only makes about 850 HP and stops pulling around 6800 RPM. Seat pressure is around 260# with open @ 750#? This is all fairly new combination and I'm looking for answers to the problem! What kind of seat pressure do I NEED??? This set up is in a dragster 1500# .999-60', 2.80-330', 4.49-660' Looking for 3.90!


Thanks, Mike

I'm no blower expert but that sounds like an awful lot of camshaft ? but aside from that I would suggest adding additional seat pressure in parrallel to whatever boost you are running. Over the base pressure the manufacturer recommends & order a case of valve springs while your at it.

 

[BlownV6]

boost,cam & springs

funny you mentioned the cam being to small, after discussions with about 8 blower experts on this subject i just ordered new cams 292/ 296 @ .050 with .748 lift. after further discussions with more experts about valve springs seems i was defenetly in left field on my springs. i have 4 sets springs off a top fuel car coming. proof is in the pudding !!! thanks for the info, seems none of the buick top dogs wanted to give up there secrets. lookin for a 3.999 ticket mike

 

[turbolou]

Re: boost,cam & springs

Originally posted by BlownV6
funny you mentioned the cam being to small, after discussions with about 8 blower experts on this subject i just ordered new cams 292/ 296 @ .050 with .748 lift. after further discussions with more experts about valve springs seems i was defenetly in left field on my springs. i have 4 sets springs off a top fuel car coming. proof is in the pudding !!! thanks for the info, seems none of the buick top dogs wanted to give up there secrets. lookin for a 3.999 ticket mike

Don't feel bad! I don't get much respect around here either.lol

 

[n20junkie]

we have lots of love for ya lou, i think the problem here is that no one runs 40+ psi that i know of, 30 or so seems to be the limit, and I would say that the top fuel springs are a good choice, i would say that the cam manufacturers are the best call for advice here, most people here are very smart, but we know what we race, your combo with a roots and 40 +psi is unknown and any advice is probably more of a guess.
Grant

 

[John Wilde]

Re: boost,cam & springs

Originally posted by BlownV6
funny you mentioned the cam being to small, after discussions with about 8 blower experts on this subject i just ordered new cams 292/ 296 @ .050 with .748 lift. after further discussions with more experts about valve springs seems i was defenetly in left field on my springs. i have 4 sets springs off a top fuel car coming. proof is in the pudding !!! thanks for the info, seems none of the buick top dogs wanted to give up there ?

Did you call Ken Duttweiler 805-659-3648?
He has several applications that run 40PSI of boost.

 

[BlownV6]

valve springs @ 40 psi

thanks to all for reply. i knew when i took this project on i was probably in uncharted territory. thousands of hours of planning, machining,fabricating, testing, etc. and i dont think i gave valve springs much consideration. how could you possibly need more than 280# on the seat, cup cars dont use nearly this much spring and they turn 9200 + for hours !!!! big mistake on my part. latest info i have is that i need 420 + to be capble of 8000 rpm !!! this would be reduced by approx 30 % if it were for gasoline. so i suspect that turbo guys with gasoline and 30 psi turning 7500 have 320 # on the seat. i run alcohol so i use about 2X the amount of fuel . this additional weight of fuel in intake charge has so much inerta above 6800 rpm that the springs need to be about 30 % heavier. i would like to thank dan white of white racing in detroit for pointing out this spring issue as the problem, i think he opened my eyes and got me looking in the right direction. i started this question after talking with him and wanted info from others. after talking with many people outside of the buick world there is little doubt that this is a very big part of my problem. of coarse this brings on other issues, lifters, pushrods, etc to handle this much spring. working on it !!! john i bet i called duttweiler 10 times and never got an answer,thought maybe i had wrong # but its the same one you gave me. thanks again to all who tried to help. mike

 

[turbolou]

Reply

Originally posted by n20junkie
we have lots of love for ya lou, i think the problem here is that no one runs 40+ psi that i know of, 30 or so seems to be the limit, and I would say that the top fuel springs are a good choice, i would say that the cam manufacturers are the best call for advice here, most people here are very smart, but we know what we race, your combo with a roots and 40 +psi is unknown and any advice is probably more of a guess.
Grant

Thanks for that! 30 # of boost & 78-8400 rpm is all I ever ran on a stage motor & never more than around 700 lift so 260 seat pressure was sufficient. I probably old school on this now. But the question is how much cam do you really need on a blown application where your relying on boost to make HP ? Its a mistake to run more cam than the heads & combination can flow. This is where an expert wih a flow bench can best advise. Any comments on this or am I off base ?

 

[John Wilde]

Re: valve springs @ 40 psi

Originally posted by BlownV6
gave valve springs much consideration. how could you possibly need more than 280# on the seat, cup cars dont use nearly this much spring and they turn 9200 + for hours !!!! big mistake on my part. latest info i have is that i need 420 + to be capble of 8000 rpm !!! this would be reduced by approx 30 % if it were for gasoline. so i suspect that turbo guys with gasoline and 30 psi turning 7500 have 320 # on the seat. i run alcohol so i use about 2X the amount of fuel . this additional weight of fuel in intake charge has so much inerta above 6800 rpm that the springs need to be about 30 % heavier. i would like to thank dan white of white racing in detroit for pointing out this spring issue as the problem, i think he opened my eyes and got me looking in the right direction. i started this question after talking with him and wanted info from others. after talking with many people outside of the buick world there is little doubt that this is a very big part of my problem. of coarse this brings on other issues, lifters, pushrods, etc to handle this much spring. working on it !!! john i bet i called duttweiler 10 times and never got an answer,thought maybe i had wrong # but its the same one you gave me. thanks again to all who tried to help. mike

Mike,

I am sorry that you did not can any info from Kenny. You have to call before 9:30AM Pacific to have a chance.
I can tell you you that our motor that is set up for 40PSI and 2100HP with Turbo Boost and spin to around 8500RPM has much less valve spring and a smaller cam!

Maybe you need 30% more but I would think that would be closer to 350 on the seat. Kenny was telling us that many people over spring their race car. He said it was costing us horsepower!

 

[turbolou]

Re: Re: valve springs @ 40 psi

Originally posted by John Wilde
Mike,

I am sorry that you did not can any info from Kenny. You have to call before 9:30AM Pacific to have a chance.
I can tell you you that our motor that is set up for 40PSI and 2100HP with Turbo Boost and spin to around 8500RPM has much less valve spring and a smaller cam!

Maybe you need 30% more but I would think that would be closer to 350 on the seat. Kenny was telling us that many people over spring their race car. He said it was costing us horsepower!

Good Logic John! but 40# boost ( gulp) How many runs do you get out of an engine pushed that hard? The EGT's created at that boost must raise hell with the valves & seats not to mention the head gaskets! Those parts must have the life expectancy of a sperm lol

 

[BlownV6]

valve springs

I use o-rings and copper head gaskets, i have had no problem with head gaskets. it does try to lift the heads( shows signs of slight leakage . we think this may be cured with lower compression. probably made 35 runs at 9.59 to 1 with no problams except valve seats would start leaking after 5 or 6 runs, looking back this was from lack of spring pressure letting valves bounce . then went to 10.64and 11.48 to 1 compression . I know this sounds rediculious to you guys but most alcohol guys run 11.0 to 1 minimum. all i saw with more compression was more destruction. next step is in 7 to 8 range . also more cam will actually lower the boost by getting the air through the motor,boost levels may have been higher because of valve hanging open ???? I have a race pack data recorder ,we kept exh temps below 1100 on advice of several blown alcohol experts and there are no sigs of trouble there. I was told buy a number of racers that 1150 is nuclear. Mike

 

[John Wilde]

Re: Re: Re: valve springs @ 40 psi

Originally posted by turbolou
Good Logic John! but 40# boost ( gulp) How many runs do you get out of an engine pushed that hard? The EGT's created at that boost must raise hell with the valves & seats not to mention the head gaskets! Those parts must have the life expectancy of a sperm lol

Lou,

The SBCs have been pretty reliable being able for the most part to run for a season. The issues with we have had are due to the fact we have asymetrical port 18* heads. The center cylinders like to leak. On Chow's 8.0 @ 175 he had one hole down more than 25%. Kenny is putting a different gasket combination on it and he said it will live. The SBCs with the symetrical heads like the canted valve and some of the brodix heads fix this problem.

The other big issue is the inconel valves don't seem to live long.
Since the stem and the head have different metalergy they have different rates of expansion as well. The is not a correct fix at this time. Kenny suggested we go with titanium and just change them every season.

Some say it is all in the tune, that is true to a certain degree but you have to have the right junk at that level.

 

[John Wilde]

Re: valve springs

Originally posted by BlownV6
I use o-rings and copper head gaskets, i have had no problem with head gaskets. it does try to lift the heads( shows signs of slight leakage . we think this may be cured with lower compression. probably made 35 runs at 9.59 to 1 with no problams except valve seats would start leaking after 5 or 6 runs, looking back this was from lack of spring pressure letting valves bounce . then went to 10.64and 11.48 to 1 compression . I know this sounds rediculious to you guys but most alcohol guys run 11.0 to 1 minimum. all i saw with more compression was more destruction. next step is in 7 to 8 range . also more cam will actually lower the boost by getting the air through the motor,boost levels may have been higher because of valve hanging open ???? I have a race pack data recorder ,we kept exh temps below 1100 on advice of several blown alcohol experts and there are no sigs of trouble there. I was told buy a number of racers that 1150 is nuclear. Mike

May I please see pictures of your combination!

 

[turbolou]

Re: Re: Re: Re: valve springs @ 40 psi

Originally posted by John Wilde
Lou,

The SBCs have been pretty reliable being able for the most part to run for a season. The issues with we have had are due to the fact we have asymetrical port 18* heads. The center cylinders like to leak. On Chow's 8.0 @ 175 he had one hole down more than 25%. Kenny is putting a different gasket combination on it and he said it will live. The SBCs with the symetrical heads like the canted valve and some of the brodix heads fix this problem.

The other big issue is the inconel valves don't seem to live long.
Since the stem and the head have different metalergy they have different rates of expansion as well. The is not a correct fix at this time. Kenny suggested we go with titanium and just change them every season.

Some say it is all in the tune, that is true to a certain degree but you have to have the right junk at that level.

I didn't know that you were envolved with Chris Chows project. Say hello to him for me! I too am envolved wiyh a TT SBC that I once owned & built & still support. I used a production 350 block & crank & pair of 23 degree AFR heads. Ran the crap out of it & held togather great. But I couldn't run it past 21# boost because of chassis limitations. 9.02 @ 155 & very streetable. Also what's your opinion of cometic gaskets? I seem to be haveing pretty good luck so far with them. Any Comments to the contrary?

 

[John Wilde]

Re: Re: Re: Re: Re: valve springs @ 40 psi

Originally posted by turbolou
I didn't know that you were envolved with Chris Chows project. Say hello to him for me! I too am envolved wiyh a TT SBC that I once owned & built & still support. I used a production 350 block & crank & pair of 23 degree AFR heads. Ran the crap out of it & held togather great. But I couldn't run it past 21# boost because of chassis limitations. 9.02 @ 155 & very streetable. Also what's your opinion of cometic gaskets? I seem to be haveing pretty good luck so far with them. Any Comments to the contrary?

I have been really good friends with Chris for about 10 years.
He does most of the work on his own car, but I do research for him. We impletment changes on his car based on his needs and my findings. For example he changed to a glide and a neil chance converter after I researched the best way for him to race his goals. We also are putting some GT series Garrett Turbos on the car this season.

I remember your v-6 ssdx car and the v-8 street car.
I also remember that you sold both to Glen Redmond.
You and kenny were the only guys using the motec.
You street car was super nice and you were one of the
first to jump the shark to the v8. My friend in New York
Bob Goldfine was the first with an all out race car that I can remember. I wish I could have bought that car or your street car.

We have not used the COMETEC but I have heard good things about them. Kenny is taking the copper gaskets out and putting in a new set of Fel Pro MLS Gaskets.

Does Glen still have the back half car and how fast did he go with it?