for some reason my car cuts off at about 5300rpms and literally has no power at all after so i have to shift just before. ive screw with the tweecer to try and fix this (happened before i got it) but i cannot. i now have no rev limiter, no fuel cutoff and no spark cutoff (mostly so my car doesnt cut out at 127mph like it used to). i cant figure out why im done so quick with my car. i know the heads arent the greatest but i had a really good guy port the hell outta the stockers as much as they could really go and he said they can outflow gt40's in a heartbeat but definately not as much as the better aftermarket heads. any ideas to why my car cuts out cause i hear 5.0's going all the way to 5800rpms with power all the time
how many rpms do you think im off?
- Thread starter HazMat404
- Start date
Rootus
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What do you mean by "only .006 more than the e303?" That sounds scary. If you are running them 0.006" from coil bind, that is why. What were/are the spring specs? Seat and open pressure, installed height, distance to coil bind?HazMat404 said:
Joe
the e303 cam has a .498 lift correct?? well these springs are for a cam UP TO .504. was told you can go over/under (under isnt that good tho) to about .010 from the spring rate to the lift of the cam and it will still be fine. you dont have to have a spring that is absolutely perfect for you cam all the way down to the exact number, you can be a tiny bit off. this is what i was told by summit and many of my friends and father's friends
Rootus
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Assuming stock 1.6 rockers, an e-cam is .498 lift. I'm not sure I'd be comfortable with only 6 thousands between max lift and coil bind.
Dave
Dave
whatcha mean "not comfortable"?? are you saying it should be closer to exact or should be further apart. heads are something that i dont know tooooo much about but have an idea. i went off of what many people said so i trusted the majority. if you think that is screwing me up really bad, ill buy new ones and replace them when i do my intake swap (god knows when that is happening) since they are right there.
thats kinda why i asked this cause its all strange to me. feed me info
thats kinda why i asked this cause its all strange to me. feed me info
so ur saying i should be higher by that much?? so i should be lookin at a .560 or something?? i thought it was made for the lift of your cam. wow...looks like i didnt do any research at all on this. i think im gonna have to be buying that trick flow lower and new springs so i can get all this done soon 
.....thanx for the info cause i thought it was right the way i had it
btw, what exactly will too tight of springs cause then??
.....thanx for the info cause i thought it was right the way i had it btw, what exactly will too tight of springs cause then??
Rootus
Officially Addicted
My valve springs are good for 0.600" of lift, and with 1.6RR my cam is setup for 0.544. I consider that a nice margin.
The problem with having such a close tolerance is that higher RPM the valves get thrown a little bit, so you may see a bit more lift than what your cam is rated for. And if the springs bind, they might break. And that would be a Bad Day.
Dave
The problem with having such a close tolerance is that higher RPM the valves get thrown a little bit, so you may see a bit more lift than what your cam is rated for. And if the springs bind, they might break. And that would be a Bad Day.
Dave
well i can swear they were for .500 lift. thats what i thought. i dont think i remember being for anything higher . ill do some research to see what im at. so ur saying like a spring up to .580 lift would be a good margin for me then?? ur scaring me on not running my car hard now (not like i can cause i busted a stud
. ill do some research to see what im at. so ur saying like a spring up to .580 lift would be a good margin for me then?? ur scaring me on not running my car hard now (not like i can cause i busted a studWhat's the installed height and OD of the stock springs? I could help you find a spring, but I'm unsure of what exactly to look for. Because they're a narrow spring OD wise, I'm guessing that the installed height is somewhere around 1.900.HazMat404 said:well i can swear they were for .500 lift. thats what i thought. i dont think i remember being for anything higher
Hazmat - you probably want to start another thread and ask what spring pressures people run with hydraulic cams. I'm running what I believe to be 130 at the seat and about 320 open.
Dave - do you know what you're spring pressures are on your heads?
Joe
Another thing I just thought of...
Hazmat - Go out and pull your valve cover off, and turn the motor over by hand. Try to find max valve lift on any cylinder and measure the distance in between the coils of the valve spring. Use a feeler gauge to do so. A digital caliper will suffice if you don't have one.
The more and more I think about it, the more I'm thinking that you just goofed on your numbers, and you are running more than an acceptable amount of clearance.
Joe
Hazmat - Go out and pull your valve cover off, and turn the motor over by hand. Try to find max valve lift on any cylinder and measure the distance in between the coils of the valve spring. Use a feeler gauge to do so. A digital caliper will suffice if you don't have one.
The more and more I think about it, the more I'm thinking that you just goofed on your numbers, and you are running more than an acceptable amount of clearance.
Joe
Rootus
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so maybe i ended up getting like a .600 lift instead of a .500 like i thought. its gonna be a few days (maybe a week or so) before i get around to this cause i got too much going on but im going to save this thread so i can check it and come back at a later time.
so im guessing i am potentially losing a lot of power and rpms outta this right??
so im guessing i am potentially losing a lot of power and rpms outta this right??
If the springs are indeed binding, then yes, you are losing tons of RPM and power.HazMat404 said:
What has me questioning whether the springs are really binding is the fact that you haven't dropped any valves yet. When springs bind, the valves have no where to go, but the rocker is going to force the valve open, no ifs ands or buts. What becomes the weak point is the retainers/keepers. The stockers aren't very strong, so when you coil bind with a stock head, I think you'd know it.
I doubt the springs are your problem. Check anyway, come back with the results, and we'll go from there.
Joe
k....well last fall i threw a valve into a piston and messed it up good. the retainers are the titanium ones (i think thats it). not the best of the market but i got good ones when i did my cam/intake swap a few years back. i think im just going to buy new ones and swap them out when i do the intake swap just to be safe cause my friends make fun of me cause i always say that my car should have so much more power but doesnt.......i hope it isnt because of stupid springs on the heads
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