boost pressure Where to set?

[Behemoth60]

what i would do is sart low say 10 psi, give a try, turn up the fuel, try again.

You're never going to learn much about your engine doing things this way. I say the exact opposite. Start high... maximize the boost. Then, each time you re-install the engine, turn it back 2 or 3 psi. When frequency of engine rebuilds becomes tolerable, leave it set there.

In all seriousness, the design of the 12HT, 1HD-T is very similar to the Cummins, and they're running 15-20 PSI stock, and regularily upgrade to 30-60 lbs for big power. Our engines already have piston cooling, excellent quality rings, pinstons, rods, crank, and an absolutely gi-normous main bearing cap that makes those ever-so-covetted-stongest-you-can-get 4 bolt main caps look like marimba chimes. Even the head gaskets are a multi layer steer (MLS as it's called in the racer crowd, sometimes called a Cometic gasket) which is what the hot rodders are abandoning their o-ringed copper gaskets for. I wouldn't hesitate for a second (there's got to be a good turbo-lag pun in there somewhere) to run 15 to 20 lbs in a 12H-T or 1HD-T. THe ONLY thing I would ever think that needs improvement on a 12H-T/1HD-T to run higher boost might be replacing the head bolts with Studs. But that's it, and for 20lbs, it's not a concern. I would, however, run an intercooler if you're pushing more than 15 lbs for more than 30 seconds at a time (i.e. towing)

An indirect injected engine, however, is a different story. I would jack the boost up on one of those as high as I can too, but when I pull it's blown ass out of the truck, it would be replaced with a direct injection engine.

I really should get my ass in gear and build that super-turbo charged 1HZ and prove once and for all just how much boost you really squeeze through an indirect injected engine. If only I had an FJ80 carcas to install it in....

Peter Straub

 

[crushers]

LOL!!
the old Peter is back, excellent...
i love a good laugh...
cheers

 

[BURGER]

if you have : oil temp, boost, pyro gauges. then you are set,

Is oil temp that critical. What kind of temps are we talking here when running more boost. How does it affect it so much?

 

[brownbear]

I might have had a slip, I have heard guys talk about oil temps. as its the only guage you don't have. You have water temp( although not always revered as accurate) you have oil px. But you don't know oil temp.

It might not be important. I have only two gauges, boost and pyro.

http://www.autometer.com/cat_gaugesearch.aspx

it would be nice to know that you are not cooking your oil.

maybe a mech oil px would be better. unless you keep getting high water temp readings I would still use the stock gauge.

maybe others can chime in.

I was thinking of adding a oil temp gauge. On aircraft it's oil temp that we monitor before applying power in the winter. we wait till it's warm enought that it's in the green arc on the instrument.

But again it would be open to discussion what is the appropriate reading and what is considered "MAX" temp.

 

[crushers]

i like running the mech oil gauge since our factory ones are always fubared for acuracy. it is noice to know if the oil pressure is stable. if the oil pressure drops and stays down then you know the bearings are on their way out (or another problem)...
cheers

 

[brownbear]

also another way to look at it, if the oil px does drop down, the oil temps could be getting quite high.

 

[crushers]

this is true...but i was talking all the time.
say you have 60 psi hot at 2000 rpms and 3 months later you have 35 psi hot at 2000 rpms constantly then you now your oil pressure has dropped for a reason... probably you have bagged on it and the bearigns are going the way of the dinosaur...

 

[brownbear]

what typically is the "range" one of these engines run at? 60 psi? just wondering if I do buy a oil px gauge then do I get the 0-100 or 0-200 gauge?

 

[denis]

I really should get my ass in gear and build that super-turbo charged 1HZ and prove once and for all just how much boost you really squeeze through an indirect injected engine. If only I had an FJ80 carcas to install it in....

Peter Straub

wasn't that engine supposed to go in tippyR ?
I say get it done

 

[BURGER]

what typically is the "range" one of these engines run at? 60 psi? just wondering if I do buy a oil px gauge then do I get the 0-100 or 0-200 gauge?[/QUOTE

I bought the auto meter sport comp oil pressure gauge 0-100psi.Seems to work fine for me.

I thik my cruiser cold goes to about the 80 psi mark and at idle hot is running around the 28 psi mark.

Going to do some tests tonight(unless I have friday beers) to see how the valve works. I will post with my results either today or tommorrow.

 

[Tapage]

what typically is the "range" one of these engines run at? 60 psi? just wondering if I do buy a oil px gauge then do I get the 0-100 or 0-200 gauge?

2F and 2H engines 62PSI @ 2000 rpm .. ( with operative temp )

 

[expat]

remember that guages are most accurate in the midrange (middle third)... so 0-100 seems about right.

 

[silvercrusher]

Why do all these web sites that I read all have a bleed off port. Is the the design for some other type of turbo or only for gas motors?

Again going on Gt theory. Bleed air is required to stop the surge and stall that can occur during startup or initial spoolup. If you have air constantly moving through the turbine you have less chance for it to reverse flow . It pretty much allows the pressure to build slowly instead of slamming the turbine with max pressure. You may be eliminating the need for this by using the variable spring setup. Try without like you said and if it doesn't "unload" Then put it on.

 

[BURGER]

Again going on Gt theory. Bleed air is required to stop the surge and stall that can occur during startup or initial spoolup. If you have air constantly moving through the turbine you have less chance for it to reverse flow . It pretty much allows the pressure to build slowly instead of slamming the turbine with max pressure. You may be eliminating the need for this by using the variable spring setup. Try without like you said and if it doesn't "unload" Then put it on.

Good explanation!