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Engine Specific Info and Questions => IDI Engine => Topic started by: allsierra123 on November 30, 2008, 11:10:11 am
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Ok here are some thoughts on this. People keep talking about running at high rpm's being bad for the diesel. But how high is too high. Doesnt the govenor keep it from running to high or is that even too high?
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I also would like to kno about this..
what about the guys that have super pumps, or home modded governers? obviously there cars are running higher then the governers were intending them to run soooo..
How high do they safely go without hurting stuff?
but to answer your question briefly I just recently watched a dyno video of Burn your money's car with nothing but a giles super pump for modifications.. and he was safely hitting near the 5000 rmp mark.. with no apparent ill effects.. However im sure sustained periods at that rpm range would cause some damage :P
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Anytime you rev an engine high, diesel or gas, you increase the amount of stress that it is under. Usually the wear caused by this will not be immediately noticeable but it will decrease the life of the engine in the end.
Basically, the higher you go the more wear you end up receiving.
IMO: anything over the IP governor is too high for me. I run about 14psi and have done a couple pump mods but I won't do the governor mod simply because if I have the higher rpm range at my fingertips(or toe tips I suppose :lol: ) then I will be inclined to use them. As my daily driver I need it to be reliable and me, as a student, need it to last a long time. :)
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What are factory red-line ratings? The factory usually does a very good job of rating the rev capabilities of a motor for max reliability. No engine will like to run at redline forever obviously, but getting it there for a little while won't hurt you unless something else is broken or worn out. For instance, a 7.3L Powerstroke will rev to redline and run there happily for maybe a minute or 5, but not much longer (not much power there anyway on that engine) but if you rev, say, 500RPM past red, most 7.3L Powerstrokes will like to break rockers and pushrods. Now, with better rods and roller rockers, thats quite different....
With a balance job and a good oil supply using high quality oils, most engines don't mind running red or around that ballpark. But then again, most engines don't have, what, 22:1 compression? :lol:
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Well The reason Im asking is because Im thinking that at 70 MPH in my van I will be running at around 4000 RPM. Im just wondering if its going to hurt my aaz to cruise at that speed.
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giles super pump on my autocross 1.6TD, .040 over, everything balanced, piston/rod assemblies extreme spread of 3grams. It feels like it quits pulling in gear around 5700 or 5800 RPM. My dyno runs were up to 5500 rpm and on the Mustang Dyno it made about the same HP from 3500 to 5500. Mustang gave different numbers depending on what weight you entered for the car, but the shape was about the same. :?
I shift around 5100 to 5200, why risk breaking something when you are not making any more power? Use the torque. Factory red line is 5100 for the 1.6TD (from memory)
::edit:: at extended time higher revs, like 4000 plus on the Hwy, oil tends to get warm. Watch water and oil temps and add extra coolers if needed
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Yeah I have a large oil cooler witha thermo comtrolled fan and an intercooler. Im not sure what else I could do to lower water temps. I will be removing the trans cooler and installing an external one that is not run off engine coolant. I was thinking on hills especially that it would cause my water temp to rise.
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hey mate,
I have an AAZ in my mk3 golf.
i would be concerned about running for extended periods at 4000rpm with the AAZ - sepecially considering that the factory governor is already starting to kick in by then.
the AAZ will provide you with enough torque to pull you along very happily at anywhere between 2500-3000rpm - so of you can work it so your tansmission ratio's are better siuted to this, you'll see the benefits in oil, fuel consumption and engine life.
in adittion to the above, i would say you'll be running far above the efficient rev range for the engine, where maximun torque is between 1800-3000 rpm. you really notice (with stock governer setup) that the torque drops right off avobe 3500rpm with the aaz, particularly given the small standard turbocharger used (K03 or K14 or T25* i think.. i have k14).
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Factory red line is 5100 for the 1.6TD (from memory)
from the manual:
1.5D redline 5200
1.6D redline 4800
1.9D redline 4600
all are as the 'lower bound' for max rpm setting. upper bound is +250rpm... i think theres a fair amount of variation in this ;-)
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Well Since I have the autobox we all know the only hope for me is to change it out for the manual. But wont be able to do this right away. So was hoping it wouldnt be to much of a problem for the 6-8 months it will take me to figure out something on the gearing. Would love to keep the auto setup though.
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So, does the govenor mod completely throw the red line out the window and it's basically ...it will now rev as high as the pump will fuel it for or until it self destructs?
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So, does the govenor mod completely throw the red line out the window and it's basically ...it will now rev as high as the pump will fuel it for or until it self destructs?
It depends on how far you take it. There are two springs that can be shimmed. The amount you shim them determines how the governor will behave. :twisted:
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Im not sure what else I could do to lower water temps.
You might already be doing this but I've heard Water Wetter (http://www.google.com/products?hl=en&q=water+wetter&oe=UTF-8&um=1&ie=UTF-8&sa=N&tab=wf&oi=property_suggestions&resnum=0&ct=property-revision&cd=2) works really well. I haven't tried it personally but just passing on what i've heard.
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Around 6000 rpm a VW turbodiesel engine will require stiffer valve springs, helper springs or shims.
As for how much the engine can take, a good pointer is the fact that all the internal parts on a 1.6 or 1.9 TD engine ar as strong or stronger than in a equivalent 8V VW gas engine. So in terms of tensile and compressive forces, a diesel engine can rev just as high.
Heat load, however is a different matter. Adding boost to a gas engine doesn't increase overall stress all that much because the tensile and compressive forces normally far outweight the stress caused my added boost.
On a diesel engine, however the high compression ratio combined with high boost pressure does affect parts durability more than on a gas engine.
Since a gas 8V can take 7000 rpm easily without mods to bottom-end parts, I would assume 6000 rpm is about the safe maximum for the td engines and even then, some bottom-end balancing wouldn't go amiss.
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Im not sure what else I could do to lower water temps.
You might already be doing this but I've heard Water Wetter (http://www.google.com/products?hl=en&q=water+wetter&oe=UTF-8&um=1&ie=UTF-8&sa=N&tab=wf&oi=property_suggestions&resnum=0&ct=property-revision&cd=2) works really well. I haven't tried it personally but just passing on what i've heard.
Also, water temps won't be a problem if you can get your injection pump set up just right and adjust boost to suit.
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would an N/a be able to handle the same rpm? around the 6000 mark with a superpump as the only mod?
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N/A would handle high rpms better, because boost doesn't cause valves to float as much and there's less load on the pistons.
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mechanical heads have any advantage?should have i suppose...
if so what the rpm limits seen on these engines?
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Factory red line is 5100 for the 1.6TD (from memory)
from the manual:
1.5D redline 5200
1.6D redline 4800
1.9D redline 4600
all are as the 'lower bound' for max rpm setting. upper bound is +250rpm... i think theres a fair amount of variation in this ;-)
but im sure they have been safely pushed beyond these numbers.. I also think that mechanical heads would have some advantage of just being.. tougher? maybe a beefier made head..? i really have no idea.
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In dont either this engine is new to me Im still learning it. But it stands to reason the beefier it is the more abuse it would stand up to. Any one have any idea of what a safe higher rpm cruising range would be on an aaz. Just dont want to go all out and push it to hard with out knowing the facts first.
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I know in gasser engines mechanical lifters are favored due to no "bleed down" at higher revs causing lower lift and duration. I'd assume the same would apply.
No idea how high it revved, but our 1.5 IDI survived a starting fluid run-away running for what felt like forever but was really maybe 20 seconds. God only knows how high of revs.