Out with the TSP 233/239, Clueless on what goes in.
06-02-2014, 12:00 AM
#1
11 Second Club
Thread Starter
Out with the TSP 233/239, Clueless on what goes in. So after having the car for 6 months and chasing valve float the whole time, the TSP cam has got to go, now that the heads are coming off.
I have heard that cam occassionally has this problem with instability.
What sucks is the car makes unreal power for our combo, until the valve float hits. One day we crossed 470 at rwhp at 6100 rpm, thru a stalled auto and it looked like it would have hit 485 if the valve float had not kicked in.
Mods are LPE 346 shortblock with diamond pistons, PRC 5.3 heads milled .023 and valve job done, Fast 92 intake setup.
We replaced the valve springs with Brian Tooley's (shimmed to 1.75), checked pr length and swapped 7.375's to 7.350's, changed the stall to an Edge 4000, replaced the coil packs, plugs, and wires.
The tune shows good a/f and no timing is getting pulled so we figure it's the cam or lifters.
I hate to pull the heads just to try new lifters (especially since they are quiet) so we are probaly just going to swap in a new cam along with the short travel lifters.
I Do Not want to make less power. Shocker, I know.
What would you do?
If a cam is involved, which one?
I wish there was something in the high 230's/ mid-high 240's w around 610-620 lift and friendly lobes that wouldn't lose too much torque down low (it made 400+) and would drive well on the street.
Our last 2 dynos the float is getting worse and hitting earlier. It sounds like the brand new valve guides and seats less than 1,000 miles) are taking a beating too. Maybe I should 't have gone to the track those 2 times? Lol
I have heard that cam occassionally has this problem with instability.
What sucks is the car makes unreal power for our combo, until the valve float hits. One day we crossed 470 at rwhp at 6100 rpm, thru a stalled auto and it looked like it would have hit 485 if the valve float had not kicked in.
Mods are LPE 346 shortblock with diamond pistons, PRC 5.3 heads milled .023 and valve job done, Fast 92 intake setup.
We replaced the valve springs with Brian Tooley's (shimmed to 1.75), checked pr length and swapped 7.375's to 7.350's, changed the stall to an Edge 4000, replaced the coil packs, plugs, and wires.
The tune shows good a/f and no timing is getting pulled so we figure it's the cam or lifters.
I hate to pull the heads just to try new lifters (especially since they are quiet) so we are probaly just going to swap in a new cam along with the short travel lifters.
I Do Not want to make less power. Shocker, I know.
What would you do?
If a cam is involved, which one?
I wish there was something in the high 230's/ mid-high 240's w around 610-620 lift and friendly lobes that wouldn't lose too much torque down low (it made 400+) and would drive well on the street.
Our last 2 dynos the float is getting worse and hitting earlier. It sounds like the brand new valve guides and seats less than 1,000 miles) are taking a beating too. Maybe I should 't have gone to the track those 2 times? Lol
06-02-2014, 08:00 AM
#3
If you want the best stability I would look into one of Geoffs EPS cam he has a 234/246 that looks like it might fit you nicely. Give him a call he's good about returning phone calls and his cams are know for being easy on the setup but still making killer power
06-02-2014, 09:25 AM
#4
What RPM are you hitting valve float? With L92 heads I am using stock lifters past 7500 rpm's with no valve train problems. I am using PAC springs and 3/8" pushrods. Do you have roller tip rockers or stock?
As long as that cams been around, its hard to believe that it would be the culprit.
As long as that cams been around, its hard to believe that it would be the culprit.
06-02-2014, 07:11 PM
#5
11 Second Club
Thread Starter
Thanks for the input guys. The EPS cam is looking pretty good.
The valve float hits pretty hard and causes a hard dip at 6400, but the graphs show power trending down compared to earlier dynos, as early as 3000 rpm. I realize the cam may not be the culprit nearly as much as the overall prior combination, especially with the pre-load being too high for so long. I kind of expect it to be a lifter problem that may have taken out the cam and damaged the heads and valvetrain as collatoral damage.
We'll know for sure when the heads come off. I'm just trying to find a good replacement cam in the meantime. One with gentler lobes even if more lift and duration.
The valve float hits pretty hard and causes a hard dip at 6400, but the graphs show power trending down compared to earlier dynos, as early as 3000 rpm. I realize the cam may not be the culprit nearly as much as the overall prior combination, especially with the pre-load being too high for so long. I kind of expect it to be a lifter problem that may have taken out the cam and damaged the heads and valvetrain as collatoral damage.
We'll know for sure when the heads come off. I'm just trying to find a good replacement cam in the meantime. One with gentler lobes even if more lift and duration.
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06-07-2014, 09:37 AM
#11
Honestly, get any of these big names to do a custom cam for your build. The little bit of extra money will leave almost nothing on the table. Thats a generic bolt on cam imo good for what it is. Just to throw out some more names, Ed Curtis and Mikey @ RapidMotorsports
06-08-2014, 08:06 AM
#13
11 Second Club
Thread Starter
06-10-2014, 01:16 PM
#15
Tooley's 232/240 cam would be similar to that TSP cam and make more power.
I'd also look at the old GM 847 clone type cams... 234/242. EPS has that as does Tick, Tooley, and LG.
Of course Ed Curtis has the 236/240 StreetSweeper which might be cut on some of the most aggressive lobes out there. And it makes power. A lot of it.
I'd also look at the old GM 847 clone type cams... 234/242. EPS has that as does Tick, Tooley, and LG.
Of course Ed Curtis has the 236/240 StreetSweeper which might be cut on some of the most aggressive lobes out there. And it makes power. A lot of it.
06-10-2014, 07:34 PM
#16
11 Second Club
Thread Starter
Wouldn't real aggressive lobes mean real hard on the valvetrain?
I'm trying to make as much usable power as possible with just the cam and lifter swap (while fixing the valve float) without going overboard to the point of destroying drivability or durability. But then, who isn't?
I'm trying to make as much usable power as possible with just the cam and lifter swap (while fixing the valve float) without going overboard to the point of destroying drivability or durability. But then, who isn't?
06-10-2014, 07:46 PM
#17
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Just food for thought and something to research (I have no desire to get into a battle about this): Throw down a little more money on the rocker set up and switch to a solid roller. You won't regret it, I know I don't regret it at all.
06-10-2014, 08:21 PM
#20
We have the entire solution to your problems. We have any lifter you can imagine, or we can give recommendations, USA Made high quality pushrods in thicker wall to reduce deflection, and we can get you any cam you want or custom grind it for less money than the rest!
You want a good quality budget lifter, the Morel 5315s are a good set, esp for your possible intended rpm range. We do have the best prices on ANY of the morels also.
Let me know if I can be of ANY help.
You want a good quality budget lifter, the Morel 5315s are a good set, esp for your possible intended rpm range. We do have the best prices on ANY of the morels also.
Let me know if I can be of ANY help.