Snedge
Comp Diesel Sponsor
- Joined
- Sep 1, 2006
- Messages
- 18,869
do they have the problem of the head lifting, stud stretching, if so how do they
solve that aspect?
They keep lots of parts and rebuild after every pass. LOL
do they have the problem of the head lifting, stud stretching, if so how do they
solve that aspect?
And I'll add to Jeff's post with a little $$$$$$ holla if ya hear me!
Listen goof ball, they don’t use gages, it take a ultra expensive piezo sensor. Listen bud, you know that we know the truth, so quite blowing smoke, when your evidently so far over your head. I have looked at cylinder pressure data logs on many types of engines, and your,,,, more than likely been closer then dreaming about that type of data logger .
Keep it up and I’ll dig a few out and print them on this thread.
We use Piezo sensors for PCP and see between 3000-3300psi and that range covers 11,13,16L engines that are all over rated tests with HP from 450-700. Not much peack Cly pressure changes for the range of cubic inch and horsepower.
top fuel 1.375in rod journal
b cummins 1.717in rod journal
k cummins 4in rod journal
i think the solution to fuel car racing is to put a modified k crank in em lol
I assume you do this on a load cell chassis dyno?
2.06 intake
Water and Electric engine dyno's
So If memory serves correct you would have to notch the top of the cly for the valves to clear, as a 2.02 will hit ???
Im sure this wouldnt be an issue for guys at this level anyway
http://www.precisionenginetech.com/tech-explained/2009/05/22/top-fuel-rings-bearings/
Greg if you can read this tell me what it says AFTER you re-read all my prior post's.......:bang
Right about when you get to this part. You'll feel even dumber...
"Cylinder pressures are incredibly high, as much as 12,000 to 13,000 PSI (when detonation takes place, cylinder pressure is in the 16,000 PSI range). To put that into perspective, a Pro Stock engine may generate around 4,000 PSI of cylinder pressure"
Greg, be Thankful for something! After all it is Thanksgiving day!
Hate to crap up the thread more than it is, BUT I find it hard to believe they are hitting those pressures.....(Again absolutely no direct experience) but when I look at the studs sticking up from the block to hold down the head I don't see that kind of pressure.
I remember reading a while back, and I don't know who's team it was but they said it was a order more difficult keeping the head seal in Top alcohol from higher peaks than it was in their Top fuel motors, and he equated it to the long burn you get with Fuel.....and when you think about it, thats were the torque is coming from. They are cracking the exaust valve with some serious pressure still in the cylinder.
However.....you can simply calculate the BMEP for a top fuel engine and that works out to 1400-1600 PSI!!!! So obviously peaks are higher right....but DAMN, its frankly hard to imagine those pressures and in reality not much for studs holding it down.
The little bit of data I saw for cylinder pressure put them in the ~5000psi range as well but again that was some time ago.
On a side note.....know of a 5.9 head that was modified for a cylinder pressure sensor? The duramax guys have it too easy!