Hi-Pop Injectors/stock motor(high-mile)

[C.K. Piquup]

I have fresh Hi-pops in a blown motor,just sittin`there.My`92GMC has 240,000miles on it and needs injectors,pump also.I know in stock application they would not be a benefit.But,are there any adverse effects of such an installation.Don`t want to hi-performance at this point w/o an overhaul.I do have a Banks dowmpipe/exhaust,K&N filter,and Banks in-fender scoop in place of snorkle.

[Turbine Doc]

I'd say use them, from my experience they probably will be more bottom end rattle than you are used to, try it if you don't like them swap back to stock.

[More Power]

If these "hi-pop" injectors were originally intended for an electronic 6.5, you "may" have some issues....

The 4-roller DS4 electronic pump generates a higher fuel injection pressure. Your DB2 2-roller pump could work, but may not generate as high a pressure, and "could" result in harder starts and lower power.

A well-worn DB2 may not generate sufficient pop pressure at cranking speed (especially while hot) to allow normal starting. Generally, one of the first symptoms of a worn DB2 is hard to start hot problems (has trouble popping the injectors). The hot thin fuel leaks past the twin plungers too easily at cranking speed (~200 rpm).

However, it might be worth a try... Then you can report back...

MP

[C.K. Piquup]

Thanks MorePower,are you saying this could be the case even w/rebuilt or new DB2?They are from my`95 motor that I replaced with the Peninsular motor.

[More Power]

Thanks MorePower,are you saying this could be the case even w/rebuilt or new DB2?They are from my`95 motor that I replaced with the Peninsular motor. You may not know what the actual results will be till you try the injectors with your DB2. However, I'd not have a high level of confidence for a good match (pump & injectors). If they don't work out for you, you could have them re-shimmed for a lower pop pressure perhaps better matching the pop pressure requirements of a DB2-4911.

Peninsular sells a DB4 (4-plunger mechanical fuel injection pump) that they use with their 340-400 horsepower marine 6.5's. These pumps would likely be a better match for the injectors you have.

My recommendation has always been to install an injection pump and injectors calibrated to work with one another. This takes a lot of the guesswork out the equation. The DP's 6.5 Project used a matched set of marine DB2 pump and Bosch injectors from Peninsular calibrated for 300-hp.

However, I would like to see a more thorough dyno test run on a 6.5, where just the injectors are swapped (comparing new factory spec to new hi-pop).

In spite of what I might think, please don't let this interfere with your experiments. At this point, I think you may as well run what you've got, then see what develops.

MP

[C.K. Piquup]

How about this.Would it be a bad move to go ahead and use a hi-performance pump on this higher mile engine?Isn`t it mostly a question of driving habits?As long as I don`t get carried away with the added power.