Need new valve springs for my M&A heads?
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That is a great cam, but what is your issue with valve springs if the track times and your build shown in your signature is current?
Are you wanting more power and RPM? What RPM do do shift to run times like in your signature?
You have a good start on your question, but not enough info to give an answer without knowing want you want to accomplish.
My car will run slightly better times than you posted with a 70 mm HPQ turbo at 16 psi, so maybe you do not shift at a high enough RPM, is your flat tappet a hydraulic or solid?
Are you wanting more power and RPM? What RPM do do shift to run times like in your signature?
You have a good start on your question, but not enough info to give an answer without knowing want you want to accomplish.
My car will run slightly better times than you posted with a 70 mm HPQ turbo at 16 psi, so maybe you do not shift at a high enough RPM, is your flat tappet a hydraulic or solid?
I don't know what psi my springs are rated at. I could could just tell you that these springs have been around for a while. The heads I have use to belong to Eric from Dynotech Performance on his stage motor. These springs were run on a roller cam set up with these heads, but when I bought the heads I went with the erson flat tappet 214/214 set up. The same springs were used on the erson cam that was used on the roller cam set up but without the inner spring, not to have enough pressure to chop the cam.
Hi Nick
My cam is a hydraulic cam. The reason I want to change the valve springs is because I am peaking HP at 4600 rpm and when I spoke to Dusty about this he said that my valve springs are probably weak and that I should be peaking HP at a higher RPM then that. The car shifts from 1st to second gear on its own at about 5500 RPM and from second to third its hard to say cause the tranny has a flare on that shift. It flares to about 5900 to about as high as 6200 and comes in at the end of the 1/4 at 5900. Dusty and David Hussek have told me that the tranny flares cause the valve body does not create enough psi to let the tranny shift on its own and that I would need to start shifting the car myself cause there would be more oil psi in the valve body that way.
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You want to control the valve train events at whatever RPM you determine is wanted or needed. I believe there's a math equation to get real or best answer ?....i went with Tim at Bullet Cams...told me to control my
(212/212/465) valve train at 6K i would need 120 on the seat. Sounds like alot for a flat cam...i am very diligent with my oils/additives. So far so good here!
(212/212/465) valve train at 6K i would need 120 on the seat. Sounds like alot for a flat cam...i am very diligent with my oils/additives. So far so good here!
If I am not mistaken, I would need to measure my spring height with the valve closed and the springs that I get can't surpass 110 psi at that height. let me know if this is the right way.
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i would suggest you seek out our head/cam pros we have here...cant go wrong.
fastblackracing
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Several things that need to thought about here, One is the seat pressure that is needed to control valve bounce as the lift cycle ends and also the open or nose pressure that is needed to keep the lifter in contact with the cam at max lift and to prevent lofting of the lifter....... When one of your springs was removed it most likely impacted one of these two requirements more than the other....so without any info on your current set up its just a WAG as to what is really going on......Your rocker ratio also plays a small part in spring requirements......Looking at the times in your signature I would say that your engine is running well and without issues, are you chasing a problem or has the car ran this way all along? .......I would not think your converter could be coupled up enough at 4600 rpm to give you a true HP reading.......With all of that said 125-130# seat pressure and 280-300# open pressure is generally the max that can be run on a flat tappet cam with any sort of success and this is pushing things.....what is the lift of your cam and what is your max installed height that you have available?......you will have to share these numbers so help can be given for spring numbers ........................................I would target 120-130 seat pressure and over the nose will be the result of spring rate and max lift.....Your ET/MPH are in line with each other and do not indicate a problem, might be a couple% high on converter slip tho.....
Its not that I am really chasing a problem, car runs great, idles great, doesn't really give me a problem. I still think the should have ran a 134 to 135 mph. On my stock motor when I upgraded to the 980 comp cam springs, I gained 2 mph on the1/4. On the dyno I peaked hp at 4600 rpm, thats to low. I am at work now, but these are the specks that I found for my cam.
GRIND DUR ADV DUR 050 LIFT L/C ad
TQ20H 292/292 214/214 463/463 111 4
fastblackracing
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I would expect to see less mph gain on the back half if springs were an issue.... 106 + 25% =132.5 looks like its on target. Is your boost holding steady on the back half ?
fastblackracing
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You all ready know that you have a trans issue.....short shifting 1-2 and flaring on the 2-3 Is costing you some.......those heads would most likely benefit from additional valve lift closer to .530 ish and the boost could stand to come up some....what compression is this combo and have you considered an .82 housing ?
The boost starts at 26 lbs in first gear and by third gear I am at 28lbs. When I finish work tomorrow, I will try to post my dyno run so you could look at it and tell me what you think.
thanks by the way,
Marco
You are right about the tranny issue, I need to start shifting the car. The compression on the motor is 8.5 to 1. So you think I would benefit with a bigger cam, I know a roller would be the best. Just love the way the car sounds stock with a flat tappet and quiet. I never wanted to go to big with cams, cause I find that sometimes bigger is not better. Next year I would like to upgrade to a 68/70 bb turbo and an Rjc front mount intercooler.
forcefed3.8's
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With a roller, you dont have to go bigger in duration numbers. A 212/212 is a great cam, and has mild lobes so it doesnt require a heavy spring. I also like the 214/214 full throttle sells, but is has the more aggressive xfi lobes, and needs a serious spring. For something really driven, I recommend the milder lobes.
I wouldnt recommend the 68/70 turbo for your combo unless you want to push into the 150mph range. I think you would be happier with the 6766. It has been proven to support 8 sec power, and will probably spool as fast maybe faster than your current turbo.
I wouldnt recommend the 68/70 turbo for your combo unless you want to push into the 150mph range. I think you would be happier with the 6766. It has been proven to support 8 sec power, and will probably spool as fast maybe faster than your current turbo.
Hi Rob, how are you.
I am still very happy with the short block you sold me, just want to get this car in the nines. I don't know if I want to put a roller cam in my car yet, I know that it is probably the way to go. I just love the fact that my car runs very quiet with not to much clacking except for a bit of the roller rockers which I guess is normal. I am trying to get this car to run as fast as I can with my flat tappet. I just want to know which valve springs to put on my heads for my cam. M&A heads are not popular anymore (old stuff), not many people have advice to give me with these heads. I would like to get this car running mid nines one day and that is why I want to upgrade to an RJC front mount intercooler and a bigger turbo. Both Cal Hartline and Jason from RJC recommend that I go with the 68/70 bb turbo with my set up. How much HP is the 67/66 turbo rated at? At first I was looking into a 71hpq billet turbo, but was told that is old stuff now. Believe me Rob, I love fast spool up, its great and fun, but already with the turbo that I am running its hard to get traction on the street. So I thought by going to a bigger turbo it will kill the bottom end a little , so it will be a little easier to get some traction on the street and have a faster top end.
By the way your car is awesome, it really rock and rolls. 8.76 at 154 mph is really kicking some ass. I could only dream of getting my car to run that fast one day.
forcefed3.8's
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I am just going by my experience with that engine and the larger q trim turbine with a front mount, it was a pig on the street. I am not sure how the 6870 acts, but cant imagine it to be any better than the old 68mm hpq. The front mount will add some lag. The 6766 is rated at 935 i think, the 67billet compressor will support over 1000. I have really changed my opinion on turbo sizes. These new turbos are killer. A friend of mine a a billet 6765, which has the old 65mm turbine that the 66 replaced, and it spools awesome on a 231, 8:1 engine. It makes boost easily at part throttle, and is controllable. The te63 on my brothers cutlass is pretty much all or nothing. Pretty similar combos, other than the turbos, but drive completely different when it comes to spool up.
Making big power that hits hard it tough on tires. But getting the turbie spped up on a large turbo sucks too, it is a fine line to walk, having the turbo ready to go, and hooking on the street.
Making big power that hits hard it tough on tires. But getting the turbie spped up on a large turbo sucks too, it is a fine line to walk, having the turbo ready to go, and hooking on the street.
forcefed3.8's
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I am glad to hear that 245" is still going strong. It is a engine. I dont see why you can do what you want with the flat tappet, i just worry about spring pressure and the cam going flat. On top of that, the larger valves in those heads will want more spring too.
Thanks for your advice Rob. Your friend that has a similar set up as your brother that is running the 67/65 turbo with the billet wheel, what does he run?
Before I upgrade turbo, I will get more informed on the topic before I buy one. I don't want my car to take forever to spool as well.
Rob, what is your opion with my car peaking HP at 4677 rpm. You don't think my valve springs have something to do with that?
Thanks,
Marco
Before I upgrade turbo, I will get more informed on the topic before I buy one. I don't want my car to take forever to spool as well.
Rob, what is your opion with my car peaking HP at 4677 rpm. You don't think my valve springs have something to do with that?
Thanks,
Marco
