Need torq for injector install on head

[HulkgreenJetta]

Looking for the torque setting to install the injectors I recently rebuilt using Vince Waldens instructions.  The rebuild was just as easy as his instructions state, POP testing was done by the local Tractor repair man. The injectors all pop tested at 2000 psi.  Hope this isn't too high.  Anyway, I am in need of a torq setting for a 1986 jetta 1.6 N/A diesel.

[jtanguay]

155 bar = 2 248.08493 pounds per square inch
130 bar = 1 885.49059 pounds per square inch

TD = 155 bar injectors
N/A = 130 bar injectors

hmmm looks like yours are just a wee bit over.  shouldn't really hurt it and its good that they're all around the same.

the torque isn't much at all.  always use new heatshields.  during the last turn you will feel the heatshield 'crush'  just basically put them in snug after that, remembering that the head is made of aluminum & the injector is made of steel.  maybe use some anti seize compound so that they are easily removed later on?  :wink:

[Powered by Spearco]

I think it's 51 ft.lbs, and yes use new heat shields, always.

[ilomax]

Josh, you should know, you did it a week ago.   I was thinkin' 55 ft lbs.  
Either way, it's in the 50's.

[gldgti]

your higher than normal pop pressures are not optimal - for IDI turbocharged you want to be pretty close to 140-145 bar. this is in the best specific fuel economy range tested in indirect injection research. the reasoning behind vw making the pressure higher is for changing proportions of combustion products...

[burn_your_money]

50 ft.lbs is what I remember off the top of my head

[Vincent Waldon]

Yup.... I just checked Mr. Bentley:

Injectors:         70 Nm or 51 ft lbs

Fuel Unions:      25 Nm or 18 ft lbs


I'll go add that to the rebuild procedure... good catch.



Vince

[jimfoo]

your higher than normal pop pressures are not optimal - for IDI turbocharged you want to be pretty close to 140-145 bar. this is in the best specific fuel economy range tested in indirect injection research. the reasoning behind vw making the pressure higher is for changing proportions of combustion products...

Actually someone on the list did some research with pop pressure on a N/A engine, and the factory spec wasn't optimal for mileage either. I don't however remember what the best was, and who's to say the difference wasn't due more to the change in timing than pressure as I don't think timing was changed during the test.

[jtanguay]

actually straight from VAG, their reasoning behind running 155 bar injector pressures was to "ensure safe fuel atomization".  didn't really have much to do with anything else.  GTD injectors pop at 160 bar and also have 12 ponies.

[HulkgreenJetta]

Sounds good to me, I have the injectors torq'd to 30 ftlbs now.  I did apply anti-seize to the threads.  Was gett'n ready to install and prime the pump lines untill my boss called me into work early.  I got lucky with finding the pop test shop, the local tractor mechanic was very knowledgeable.  He told me that the nozzles would slowly break in, so it wouldn't be a problem.  All for 25 minutes and $20.  
 
  Before the injectors began leaking, I was driving from San Diego,CA to Cedar City, Utah on 7.5 to 10 gallons of Diesel.  Thats 489 miles getting 52 to 63 mpg. I am hoping to get the same mpg after the rebuild.  
 
  11 months ago my bud and I finished his Suzuki Samuari to VW 1.6 N/A conversion.  His Dub-Zuki is getting 45 mpg an runn'n fine.

Thanks for the reply's

[gldgti]

ahh the complexities of diesel injection... i wish there was a simple formula to work out the ideal pop pressures...

its certainly a big area... we need more diesel minded thermodynamics modellers..

[rabbitman]

Yup.... I just checked Mr. Bentley:

Injectors: 70 Nm or 51 ft lbs

Wierd, my mk1 bentley says 52ft-lbs. :?

[Smokey Eddy]

I got
70 Nm (51 ft. lb.)