Cam runs out early?
12-13-2011, 09:53 AM
#22
Shouldnt Datamaster be pretty accurate? I know the factory tachs are not very accurate to rear life. I forgot how high it went on my dash but im trying to think 62-63 maybe i know it was a touch higher then what the log showed.
In the datalog while doing the run it showed peak airflow at the 6-61 mark. My tuner said the rpm reference on the dyno had to of been off. I asked that questions why so low as it wasnt close to where it should have made peak power which is 61 off lloyds site. If it made peak power at 5650 there is a serious problem and leaving a big opening for more power to be made being the springs if its running out that early?
In the datalog while doing the run it showed peak airflow at the 6-61 mark. My tuner said the rpm reference on the dyno had to of been off. I asked that questions why so low as it wasnt close to where it should have made peak power which is 61 off lloyds site. If it made peak power at 5650 there is a serious problem and leaving a big opening for more power to be made being the springs if its running out that early?
Last edited by 95mysticta; 12-13-2011 at 09:59 AM.
12-13-2011, 10:23 AM
#24
Village Troll 
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Unless there's something wrong with the Dynojet software I would say that RPM is spot on. IIRC both RPM and torque are calculated through the Dynojet's inductive pickup. If you think your RPM is off then your torque is off as well. From that graph and what I see/IMO RPM looks accurate and makes perfect sense regarding your problem being valve float.
12-13-2011, 10:25 AM
#25
These PAC 1518s are good to .650 lift wtf 
So going back to the start of this tread where i noted that these required a good shim to get them to the right height when my builder r&r'd them. What do i need to do with that shim issue and what kind of springs should i look into so i can fix this issue when i put the cam in next year? Also if im getting float does that mean they are robbing power in my current state not being adequate or are the fine only untill they reach that rpm?
So going back to the start of this tread where i noted that these required a good shim to get them to the right height when my builder r&r'd them. What do i need to do with that shim issue and what kind of springs should i look into so i can fix this issue when i put the cam in next year? Also if im getting float does that mean they are robbing power in my current state not being adequate or are the fine only untill they reach that rpm?
12-13-2011, 04:14 PM
#29
I could be wrong but this dyno had a pickup thats setup to get the rpm reference from the accessory drive.You can see it from the video its going underneath the front of the car. If the springs are no good im curious to see what a set of good springs have in store for my car i might even not want to cam up if its still making that kind of power way way below where it should be peaking 
12-13-2011, 07:42 PM
#30
wrd1972 went through a lot of hassles with multiple sets of springs and eventually a cam swap to solve his issues, he wouldn't listen, bought springs stronger over the nose but with no more seat pressure etc.
loss of valve control over the nose of the cam at rpm is just free lift, what costs power is when it bounces back off the seat letting compression escape. So it doesn't matter if a spring can handle .700 lift and you are only using .500 that doesn't make it an adequate spring, it might be, it might not.
loss of valve control over the nose of the cam at rpm is just free lift, what costs power is when it bounces back off the seat letting compression escape. So it doesn't matter if a spring can handle .700 lift and you are only using .500 that doesn't make it an adequate spring, it might be, it might not.
12-13-2011, 08:07 PM
#31
wrd1972 went through a lot of hassles with multiple sets of springs and eventually a cam swap to solve his issues, he wouldn't listen, bought springs stronger over the nose but with no more seat pressure etc.
Anyways just a quick info plate
the pac 1518 from what i can find are 133 closed, 318-330 open
The patriot 8401 golds are 135 closed, 375open.
Closed isnt much of a difference, but open your looking at 50lbs which might cure some issues.
Since i was running ls7 lifters and my max install height was 1.780 instead of 1.800, i was reccomended the 8401's over the 8501's. Bought a set of 8501's and had to return them due to this issue, and the ls7's cant take pressure 8501's would give at 1.780 lol. The 8501 is 155 closed and 410 open. Considering you said the heads were old, the pac's probably lost the first initial pressure drop. 6000 miles might be enough to do that.
The 8401's are a nice peice to me, id reccomend them! Once the valve covers come off this weekend ill take some pics after some abuse from a cam that has eaten up alot of other valve springs in its life lol. maybe ill find some busted *** ones maybe i wont. Maybe some missing keepers or a valve spring just laying in there would be cool. My tach does go way over 6000 though, and seems to still pull to 6500 ish. I have no dyno graph to prove anything of valve float or a massive power drop though.
Shitty that your dyno rpm was off too, that really throws everyones judgement on whats really going on. If the tach in your car doesnt want to go over 6100, thats very very odd. Its possible your valve springs mightve gotten to weak, or were to weak to begin with.
Last edited by trilkb; 12-13-2011 at 08:13 PM.
12-14-2011, 07:48 AM
#34
I have his old cam (lol). Im running patriot 8401's, no huge issues yet, getting ready to pop a valve cover off for the first time in a couple hundred miles and a track pass + high rpm backroad abuse since the build. I was specifically told not to run beehive springs by LE. Ive talked to WRD1972, didnt buy the cam from him though (small world) But i dont think he tried the 8401's. He deffinetly gave me some heads up about it, so did LE though. I wouldnt expect him to grind the cam the OP has to the same aggressive specs.
Anyways just a quick info plate
the pac 1518 from what i can find are 133 closed, 318-330 open
The patriot 8401 golds are 135 closed, 375open.
Closed isnt much of a difference, but open your looking at 50lbs which might cure some issues.
Since i was running ls7 lifters and my max install height was 1.780 instead of 1.800, i was reccomended the 8401's over the 8501's. Bought a set of 8501's and had to return them due to this issue, and the ls7's cant take pressure 8501's would give at 1.780 lol. The 8501 is 155 closed and 410 open. Considering you said the heads were old, the pac's probably lost the first initial pressure drop. 6000 miles might be enough to do that.
The 8401's are a nice peice to me, id reccomend them! Once the valve covers come off this weekend ill take some pics after some abuse from a cam that has eaten up alot of other valve springs in its life lol. maybe ill find some busted *** ones maybe i wont. Maybe some missing keepers or a valve spring just laying in there would be cool. My tach does go way over 6000 though, and seems to still pull to 6500 ish. I have no dyno graph to prove anything of valve float or a massive power drop though.
Shitty that your dyno rpm was off too, that really throws everyones judgement on whats really going on. If the tach in your car doesnt want to go over 6100, thats very very odd. Its possible your valve springs mightve gotten to weak, or were to weak to begin with.
Anyways just a quick info plate
the pac 1518 from what i can find are 133 closed, 318-330 open
The patriot 8401 golds are 135 closed, 375open.
Closed isnt much of a difference, but open your looking at 50lbs which might cure some issues.
Since i was running ls7 lifters and my max install height was 1.780 instead of 1.800, i was reccomended the 8401's over the 8501's. Bought a set of 8501's and had to return them due to this issue, and the ls7's cant take pressure 8501's would give at 1.780 lol. The 8501 is 155 closed and 410 open. Considering you said the heads were old, the pac's probably lost the first initial pressure drop. 6000 miles might be enough to do that.
The 8401's are a nice peice to me, id reccomend them! Once the valve covers come off this weekend ill take some pics after some abuse from a cam that has eaten up alot of other valve springs in its life lol. maybe ill find some busted *** ones maybe i wont. Maybe some missing keepers or a valve spring just laying in there would be cool. My tach does go way over 6000 though, and seems to still pull to 6500 ish. I have no dyno graph to prove anything of valve float or a massive power drop though.
Shitty that your dyno rpm was off too, that really throws everyones judgement on whats really going on. If the tach in your car doesnt want to go over 6100, thats very very odd. Its possible your valve springs mightve gotten to weak, or were to weak to begin with.
The graph is totally fooling alot of people im not big into the dyno stuff but again my tuner has the log and he told me that the rpm had to of been as it didnt make sence. Im not saying that it is right cause im not the expert im learning and trying to figure out this issue to get it solved so i dont run into problems down the road or limit my motor if the springs are too weak.
So can anyone answer this question: What can i do when i go to put the springs on the heads with already using a big shim? Should all of my valves be at the same height or can they be all within a given gap and be fine? Anything i can do to correct this?
Thanks for the input so far guys, really appreciate it!
12-14-2011, 08:21 AM
#35
Resident Racing Jerk
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So can anyone answer this question: What can i do when i go to put the springs on the heads with already using a big shim? Should all of my valves be at the same height or can they be all within a given gap and be fine? Anything i can do to correct this?
Thanks for the input so far guys, really appreciate it!
12-14-2011, 09:34 AM
#36
Also you continue to get the facts wrong, I never did install Patriot Golds on my motor with the LE1.5 cam. I installed them on anothers car with the identical cam and we quickly determined on the road and on the dyno that the valve control issues were history. I then installed the tamer LE1 cam on my car with the existing beehives and determined on the road and on the dyno that even with the beehives, my valvetrain was in total control.
Because of the beehive failure issues of years ago, I decided to install the Patriot Golds on the engine because I had more piece of mind with dual coils as opposed to a single copil spring and I had never read of significant issues with the quality of the Patriot springs. The Patriot Golds are very near the spec of the PAC 1518s and they continue to work fine to this day.
I must assume that if I installed a AI cam then, then you would not continue to post "he wouldnt listen" and further might end up in your good graces. This **** just gets tired after this many years.
12-14-2011, 09:40 AM
#37
Village Troll
iTrader: (2)
... and if that is the case you should go ahead and have new valve guides and seats put in. Theoretically all of your guides should be w/in a few thousandths of eachother, but as stated you need to measure each one and shim accordingly.
12-14-2011, 03:08 PM
#38
Also you continue to get the facts wrong, I never did install Patriot Golds on my motor with the LE1.5 cam. I installed them on anothers car with the identical cam and we quickly determined on the road and on the dyno that the valve control issues were history
OP, Im not saying the 8401's will be a direct cure for you. However If valve float is your issue, they should probably help. To much spring pressure is just as bad as to little spring pressure. The fact your heads have different spring pockets isnt good either, I would try to install them all close to the same with a small, but ample, tolerance. Obviously if one is severly higher or lower then another, that will effect things.
Get ahold of LE and ask what he thinks about 8401's for your setup, thats really the best approach.
