emissions delete/perfect threaded plug for open holes

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89rebelpup
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Isuzu vehicle(s): 1989 Standard cab swb 2.3l (carb)

emissions delete/perfect threaded plug for open holes

Postby 89rebelpup » Fri Jun 10, 2016 7:05 am

For all those who have removed their emissions equipment and realized how difficult it is to locate the exact size of M14x1.25 in a bolt, plug, cap or any possible threaded contraption ever created... I may have figured it out!

If I am not the first or if it has been tried and found to be another failure forgive me and I'll be okay with that and we can move on! :)

Go to most any parts store, walk back to the motor oil and associated equipment and look for the display containing replacement vehicle oil pan plugs.. among the various sizes available you should find both magnetic and non-magnetic plugs sized M14x1.25! ..I have found that usually each store only stocks one or two of any size so it may take a couple stops but finally the search is over, the mystery is solved and the 4 holes in the engine can be properly filled in a neat and orderly fashion.

Rebel
Last edited by puttputtinpup on Fri Jun 10, 2016 7:22 am, edited 1 time in total.
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puttputtinpup
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emissions delete/perfect threaded plug for open holes

Postby puttputtinpup » Fri Jun 10, 2016 7:18 am

Sounds good! Thanks for sharing that with us,
Last edited by puttputtinpup on Fri Jun 10, 2016 7:23 am, edited 1 time in total.
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oldestisuzuist
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Re: emissions delete/perfect threaded plug for open holes

Postby oldestisuzuist » Fri Jun 10, 2016 8:53 am

Just be aware that the oil drain plug head may be too big to fit into the head recess plus the recess is tapered, not flat. The hex portion of the original air rail fitting is quite small & fits within the head recess. The fitting actually seals on the bottom against a slight lip in the head, not against the bottom of the hex portion. Oil drain plugs are probably too short to seal against the lip, so you may experience sealing problems.
Also on rare occasions you may develop a "chirping" after replacing the air rail fittings with something else that is shorter than the original. This is caused by the exhaust gas pulses passing across the open hole in the runner left when the air rail fitting is removed, similar to blowing across a bottle neck.
My recommendation is to use the original threaded air rail fittings, they seal properly, fit into the head recess & don't cause weird noises. Cut the air rail pipes & remove from the fittings, then plug the hole in the fitting (drill & tap for a bolt, solder/braze, liquid weld), re-install the fitting.
Do something similar to the M22x1.5 fittings on each end of the EGR tube at the intake & exhaust manifolds to remove even more emissions.
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89rebelpup
Regular Member
Posts: 33
Joined: Sat Apr 23, 2016 3:46 pm
Location: Georgia
Isuzu vehicle(s): 1989 Standard cab swb 2.3l (carb)

Re: emissions delete/perfect threaded plug for open holes

Postby 89rebelpup » Fri Jun 10, 2016 10:05 am

I respect your opinion and wisdom on the matter,

Previous to buying my pickup the seller had removed the air rail fittings and replaced them with these bolts that are way too long but they tighten. Until I read here on isuzupup and experienced the impossible search for a suitable filler firsthand I assumed after the purchase I could just buy shorter bolts.
Uh.. yeah NO!
On another but now known to be a related note, before my purchase of my pickup I mentioned the "chirping" sound when accelerating and neither of us associated the incorrectly seated bolts and the chirping. The seller said he thought it was probably just a loose exhaust flange bolt and he or I could tighten it and that sound would go away. That made close enough sense to me so I agreed to just handle it myself after the sale.
But then I found nothing loose or leaking and learned here how the two are related. Then while researching the elusive size and thread patterned bolt I stumbled on this idea. Personally I believe it will work even if it doesn't silence the chirp (kinda gotten use to the unique sound actually) at least the holes will be sufficiently sealed-up and it will look alot better than known alternatives.
Rebel

89rebelpup
Regular Member
Posts: 33
Joined: Sat Apr 23, 2016 3:46 pm
Location: Georgia
Isuzu vehicle(s): 1989 Standard cab swb 2.3l (carb)

Re: emissions delete/perfect threaded plug for open holes

Postby 89rebelpup » Sat Nov 04, 2017 11:44 am

Dumping the nylin washer for aluminum washer, why wouldn't these work?

http://www.clipsandfasteners.com/Oil_Dr ... a18024.htm