Spring recommendation for GN1s

[jpwalt1987]

I would run zero preload. Jwalt isn't sure if his problem is valve float either.

Well I guess the first thing to do is adjust to zero preload and test it out. I have to test on the back roads because the track is an hour away and only open on Saturdays. Brian, looking at the screen shot on the first page you can see what the converter goes to when I go WOT. Do you think if I could get the engine to Turn 6000 that I would be ok with that power band? Not sure where to go from here now.

 

[Quik Six]

I would run zero preload. Jwalt isn't sure if his problem is valve float either.

I looked at toomanymodz latest PL file and made some recommendations for changes to his chip settings and he has some leaks to find. Pretty sure the valve train is not his causing his problem.

 

[toomanymodz]

I received the email QuikSix. Thank you for your analysis. Remember, WOT BLM's can go up or down in real-time due to wide-band correction (6.0 chip). My boost drops a couple of pounds above 4900, so the chip starts pulling fuel. I think I was shipped a standard actuator instead of an HD actuator, coupled with the fact that I have a large ported WG hole with the large RJC puck.

My BLMs at idle have always been high (139 to 142 range), even with the old engine, so I suspect a leak under the dash somewhere. I'll run the other items past Eric.

 

[bison]

Well I guess the first thing to do is adjust to zero preload and test it out. I have to test on the back roads because the track is an hour away and only open on Saturdays. Brian, looking at the screen shot on the first page you can see what the converter goes to when I go WOT. Do you think if I could get the engine to Turn 6000 that I would be ok with that power band? Not sure where to go from here now.

It looks like it's going to 5400. It's not going to get much better than that. It should be a rocket @30psi between 5400 and 6000. I'd still try and keep it between 5400 and 6000 as long as possible with that cam/turbo. Peak flow will be around 3:1 PR/ 5700rpm.

 

[bison]

Well I guess the first thing to do is adjust to zero preload and test it out. I have to test on the back roads because the track is an hour away and only open on Saturdays. Brian, looking at the screen shot on the first page you can see what the converter goes to when I go WOT. Do you think if I could get the engine to Turn 6000 that I would be ok with that power band? Not sure where to go from here now.

 

[jpwalt1987]

It looks like it's going to 5400. It's not going to get much better than that. It should be a rocket @30psi between 5400 and 6000. I'd still try and keep it between 5400 and 6000 as long as possible with that cam/turbo. Peak flow will be around 3:1 PR/ 5700rpm.

It is fast now at 24 psi! The MTs go up in smoke at 45-55mph. I can't imagine 30psi. I may have to just ignore my audible knock sensor and see if it will to 6000 in a lower gear. The audible always goes off at 5500 and then I shift it to the next gear.

 

[toomanymodz]

Let me know how that goes. If I hold mine in 1st or 2nd, the acceleration completely stops at around 5500 rpm. I agree, I couldn't imagine 30 psi. High 9's would be in the cards (assuming everything holds together).

 

[jpwalt1987]

Let me know how that goes. If I hold mine in 1st or 2nd, the acceleration completely stops at around 5500 rpm. I agree, I couldn't imagine 30 psi. High 9's would be in the cards (assuming everything holds together).

I will know pretty quick if it will pull past it. 9s is what my motor was built for!! Time to test it out.

 

[bison]

It is fast now at 24 psi! The MTs go up in smoke at 45-55mph. I can't imagine 30psi. I may have to just ignore my audible knock sensor and see if it will to 6000 in a lower gear. The audible always goes off at 5500 and then I shift it to the next gear.

If you have verified tdc and checked timing then run some 116 octane and see if the retard goes away. If it does then you had detonation. If not it's something else. Ive never seen 116 octane detonate on any application. Not that it couldn't but it's not going to in your instance if everything else checked out ok. If that log was 24psi you will drive into the converter a lot harder with 30. I'd switch to high viscosity hydraulic oil in the trans to lower the couple speed a little. It's really good at your current level though. Even if the converter won't couple well with added boost I'd still be shifting around 6000. In 3rd if it's too loose it will just go past 6000. It's more important to keep the engine near peak power at the beginning of a pass than at the end.

 

[jpwalt1987]

If you have verified tdc and checked timing then run some 116 octane and see if the retard goes away. If it does then you had detonation. If not it's something else. Ive never seen 116 octane detonate on any application. Not that it couldn't but it's not going to in your instance if everything else checked out ok. If that log was 24psi you will drive into the converter a lot harder with 30. I'd switch to high viscosity hydraulic oil in the trans to lower the couple speed a little. It's really good at your current level though. Even if the converter won't couple well with added boost I'd still be shifting around 6000. In 3rd if it's too loose it will just go past 6000. It's more important to keep the engine near peak power at the beginning of a pass than at the end.

I verified the timing back when I had a gen 1 big stuff 3. It was one degree off. I had tried some Sunoco 116 at 18-22 psi boost and 18-22 degrees of timing and still had rpm related knock retard. That's why I have been leaning towards the valve train being the cause. What kind of hydraulic fluid should I use ? It has type F in it now. It's a TH400.

 

[bison]

I verified the timing back when I had a gen 1 big stuff 3. It was one degree off. I had tried some Sunoco 116 at 18-22 psi boost and 18-22 degrees of timing and still had rpm related knock retard. That's why I have been leaning towards the valve train being the cause. What kind of hydraulic fluid should I use ? It has type F in it now. It's a TH400.

I run the high viscosity that John Deere has in 5 gallon pails. Your knock retard is almost definitely bogus. I'd still check the timing one more time if you have removed the balancer or changed the crank sensor or disturbed it in any way.

 

[turbobusa69]

The comp 26120 conical springs would be about the least I'd run for that cam. Ive ran them up to .550 lift/6000rpm sucessfully.160-170 on the seat and about 450 open. There is no point in putting in a marginal set of springs.

bison, i have the engine sloGN mentioned. i was at richard clarks shop yesterday and had the comp 26120 springs with the retainers they call for. we tried setting them up on my heads and they are so close to coil bind(.025-.045). this is with no shims and installed height is 1.725. are you sure this is the right comp part number valve spring that will work on iron heads? if so do you have any other idea what i should try? also seat pressure was about 190 and open was about 380 so i didnt see the 450 open pressure you mentioned thanks john

 

[bison]

That's plenty of clearance. Seems like the open pressure is low. I'd see what you get out of it before you make anymore changes.

 

[turbobusa69]

after talking with comp cams, they dont recommend running 26120's closer than 050-060. so i think i will try another spring. i attached the comp cam pdf on the 26120's

http://www.compcams.com/WhatsNew/Files/26120 Beehive Spring2.pdf

comp gave me part number 978-16 a dual spring that they think is a better option. i have ordered K motion #750 springs and will try these this weekend and see how they check out.

 

[qws2000]

my car is having a spring problem, also (i think) I was informed that at the seat is 140 ish and the open is like 330. This info was from Champion Heads... My car is pulling fine in second gear till 4900 rpms then it just breaks up till I up shift... When it breaks up seems like the car is stuck in the mudd. The builder said the car should rev till at least 6200rpm. We are tryn to find a spring that has a 155-170 on seat and 390-420 in the open... I really dont know enough of this area, but really trying to learn, since it is my car!! What do you guys think? Right or could b something else...

 

[turbobusa69]

qws2000, my car wasnt getting past 5400 but i did have about 356lbs open pressure with my old pac springs. i currently am waiting on the K motions 750. these are supposed to be around the 130-140 seat and 400 open with my cam. i dont think the seat pressure is our issue. long as the spring rate rises fast and gets to around 400 at open. will have these this weekend and will set them up and see what the pressure works out to.

 

[qws2000]

Thanks for info 69,... But the builder told me the seat preasure is just as important, something like if not the car will fall on his face.... this stuff is way over my head, im trying my best to hang with this thread...Al

 

[turbobusa69]

i disagree about seat pressure qws2000. v8s typically run 120-150 seat pressure depends on valve train weight. so i highly doubt a buick v6 valve train is heavier than a big block chevy. the issue with our motors for open pressure is the boost pressure on the back side of the valve needing more spring pressure to close.

 

[qws2000]

ok, sounds good.... What spring are you using? What cam do you have? and are the heads off the motor? I think he likes PAC1206, and 99846 crane I think?

 

[turbobusa69]

i have PAC beehive springs that came in the full throttle roller cam kit. i also have the 215/220 roller with .517int .530exh lift with 1.55 t/d roller rockers. heads are off and motor is out. not sure the exact part number that comes in the kit since the springs came in a zip lock bag. mike at full throttle had another PAC to try, think it was a 1200?? but the spring was only a few pounds stronger than the current ones i have and im not sure that would be enough. so i have tried the comp 26120's and looks to tight to me from coil bind. so now i have order the K motions 750 and they will be here today or 2mrrw. so will try them this weekend and see.