Don Terrill’s Speed-Talk

Thanks, that is good to know. Ya the power is decent if I could keep it together. it will be going back on the dyno in a month, so I am just trying get things to look at. timing is another thing which seems high to me at 32 deg all the way up to 22 lbs.

Ya sorry got pulled away and didn't realize that I hit post. Edited it. I do not have any back pressure measurements but will be doing that. I guess wondering what I should be seeing at the turbo flange?

Running 2 60 mm compressors at 1000 hp with ex turbin AR of .68. seems very touchy for tulipping valves. It is a 260 ci running e85 @ 15 lbs @ 7200 rpm.

What is the application? Two of the racers that I have rubbed shoulders with over the years have both logged data of the water pressure of their boats open cooling system. One was a drag boat and the other a circle sprint boat. Both were shocked to see water pressure well over 100 psi in the heads ...

gruntguru wrote: ↑Tue Sep 10, 2019 1:43 am 8.7:1 CR, 22 psi boost on E-85 should be able to run MBT timing without det.

We dont see ANY det at all and it does concern me some. the timing is up at 32 deg even at the 22 lbs of boost. can a person not see any det but still be causing issues?

On a hard running turbocharged motor the exhaust valves run hot(er) Especially if the spark timing is run retarded to avoid detonation under wot boost. So this makes the hotter ex valves grow in stem length when run at wot under boost. May want to open up the ex valve lash setting a bit more to com...

I was afraid you were going to say to stay with the solid roller. We have just had a lot of problems with solid roller valve train not being forgiving enough. We see some times the valve job will start to go. Not enough to tulip a valve but enough that we start to notice. We run multiple leg maratho...

I have an odd ball combination and I have posted about it on here before but rather than everyone have to read through the whole post I will give a condensed version of here. LS based 260 Ci twin turbo on e85 8.7: comp 3.89 bore x 2.725 stroke mast ls1 heads holley hi ram and holley fuel injection c...

That is correct. The old lt1 was but that ended a while ago. Lots of issues doing it when using a closed cooling system apparently but I do not know of any when using an open system.

Looking at reverse cooling an LS engine with an open cooling system. Meaning now water pump just water supplied from an outside source and exiting back to that source.

Great job. =D> I'd like to have a peek at the dyno sheets of both the 15psi and 32psi if you don't mind. Did you ever figure out what killed those exhaust valves in the beginning? Dont think a guy will ever see the 32 psi one. It was kind of a whoops apparently. Wasn't enough water flow through the...

Well a little update on this project. Installed 8 egt sensors in the headers and ran it at 15 psi boost 30 deg timing and 1000hp@7300 for a 4 min dyno run and egt's stayed below 1400f. All are very close so this thing seems to be finished. made one pull at max boos but kept the rpm low. 1382hp@6400...

Well a little update on this project. Installed 8 egt sensors in the headers and ran it at 15 psi boost 30 deg timing and 1000hp@7300 for a 4 min dyno run and egt's stayed below 1400f. All are very close so this thing seems to be finished. made one pull at max boos but kept the rpm low. 1382hp@6400 ...

Did you mean peak TQ or peak HP at 7300? If boost is constant I have a hard time with it not making peak torque by 7300rpm. Unlike a wide band, the EGT probe's can be on the underside of the header. In this one we only went to 7200 and tq was still increasing at 11 psi consistent. The bottom of the...

Wouldn't that say that the exhaust cam is more likely to be too long duration than too short duration? In my view it is maybe 4 deg long as well as the intake but its pretty close. We cam doctored the cam just to make sure nothing was weird from what the cam card said. Such a small engine that it d...