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-   -   How To Drill Holes In The Block And Not Get Shavings In The Engine? (https://www.rx7club.com/1st-generation-specific-1979-1985-18/how-drill-holes-block-not-get-shavings-engine-153279/)

RotorMotorDriver 01-28-03 09:34 PM

How To Drill Holes In The Block And Not Get Shavings In The Engine?
 
Ok, I have ONE LAST LEAK that need to be fixed. Some of you may or may not know, I have JB weld from the previous owner on my rear plate where the oil pressure sender is supposed to go. I have a feeling it was covered up because they stripped it out or something stupid like that. Anyway, its SLOWLY leaking from around the JB weld, and its just pissing me off. I talked to my uncle who is a damn smart guy, and he suggested against trying to JB weld over it again cause it was just asking for trouble. I agreed, and asked about drilling, tapping, and putting a plug in or whatever. I wasnt sure how to do this without getting a bunch of shavings all inside my engine. He said that back in high school in shop class, when they had an engine that had a leak but they didnt know where it was coming from, they used to hook up a regulated compressed air source (~3 PSI) to the dip stick tube, and then go around with soap water and look for bubbles. He said that he didnt see why I couldnt pressurize my oil system with about 3 PSI then drill and tap the hole, because the compressed air, along with some oil wouldnt let the shaving go into the engine, instead they would be pushed out. I cant see why this wouldnt work, but I just thought Id ask you guys for another opinion before I do it.

~T.J.

Felix Wankel 01-28-03 09:45 PM

Put grease on the drill bit and the tap.

Keaponlaffen 01-28-03 10:52 PM

magnetize the drill bit and the tap?

RotorMotorDriver 01-28-03 11:00 PM

I thought about all that...But you guys are avoiding the real question. It would be basically impossible for shavings to fall into the engine if there was air pushing them out...Can I do this or not?

~T.J.

EDIT: This sounds angry. I cant think of how to re-word it so it doesnt, but Im not mad :). Sorry if it sounds like that :).

mar3 01-28-03 11:23 PM

Chaos rules regarding turbulent air flow at the drilling area guarantees some shavings will get into the engine despite the compressed air...seriously...the thick grease idea and slowly working the tap is a much better idea....finish the bass coffin...:cool:

DriveFast7 01-28-03 11:31 PM

Doesn't sound angry to me; you're just making a point. :)

3 PSI really isn't much air pressure. I'd need more than that before trying something like this. That port leads down to the rear oil pressure regulator and up to the oil filter so you got some options. Drop the oil pan, remove rear oil pressure regulator and oil filter. Put compressed air into the rear oil pressure regulator port and drill and tap that JBweld port, assuming you can even get a drill or dremel tool in there. Clean it all up and install a Racing Beat 85 PSI rear oil pressure regulator and a baffle plate while you got the pan dropped!!!!! I'd be that oil pan gasket is leaking as it is so good idea to drop the pan and regasket anyways.

You might be able to try a heli-coil in there to rethread it.

Or use Devcon Aluminum Putty. Denser and stickier than JB Weld. MarineTex (sp) is even stronger!

Of course to do it right you need to take that back plate off. Some rotary shops are willing to just take the back housing (s) off to fix a prob back there.

-bp-

MarkPerez 01-28-03 11:33 PM

Yes ! it could work,check it out man. there is no way to drill INTO an engine, all the way through it, then tap the hole. some bits WILL get in no matter how much air is pumped into it, can't get around it. how about drill only half way through, then tap that. might be better, thats a good idea felix about the grease on the tap. good one! man.

Directfreak 01-28-03 11:33 PM


Originally posted by RotorMotorDriver
I thought about all that...But you guys are avoiding the real question. It would be basically impossible for shavings to fall into the engine if there was air pushing them out...Can I do this or not?

~T.J.


Well, if you're gonna have an attitude...


Originally posted by RotorMotorDriver
EDIT: This sounds angry. I cant think of how to re-word it so it doesnt, but Im not mad :). Sorry if it sounds like that :).
Nevermind. ;)

RMD, where does the oil go behind the stock oil pressure sender location? If it's nowhere serious, maybe any shavings could just fall into the oil pan, (which you could remove easily). I am guessing on this one.

The stock Oil pressure sender is (almost) the same as 1 1/8 in NPT plug. You can actually cross thread it by accident if you put the NPT sender in it.

The ACTUAL thread is a British-spec thread. I forgot the actual name, but "British" is in the name. Same thing happened when I was looking for a fitting on my wastegate. They sell those fittings at Home Depot.

You can use a maganatized drill bit
You can use grease on the drill/tap
You can "Pressurize" the crankcase
You can tap with a shop-vac right next to the tap.
You can do all of the above..

I've known people to drill and tap their front covers this way (for turbo returns) out of laziness.

680RWHP12A 01-28-03 11:40 PM

no matter what you do metal shavings will get in the motor! i dont care what you do!
you might get lucky or maybe not!

the question is can you put up with the oil leak?or worst case senario if you do drill it out and metal shavings f**** up the motor, can you be without the car?

RotorMotorDriver 01-28-03 11:53 PM


finish the bass coffin...
No money :cool:

I'd be that oil pan gasket is leaking as it is so good idea to drop the pan and regasket anyways.
New pan and gasket before the engine went in les that 7K miles ago :).

Or use Devcon Aluminum Putty. Denser and stickier than JB Weld. MarineTex (sp) is even stronger!
Anyone else heard or used of this stuff?

RMD, where does the oil go behind the stock oil pressure sender location? If it's nowhere serious, maybe any shavings could just fall into the oil pan, (which you could remove easily). I am guessing on this one.
I dont know.

The stock Oil pressure sender is (almost) the same as 1 1/8 in NPT plug. You can actually cross thread it by accident if you put the NPT sender in it.
I was going to tap it 1/8 NPT for simplicity, and also to keep from making it too big and hitting a coolant passage or something.

I've known people to drill and tap their front covers this way (for turbo returns) out of laziness.
I was thinking that too. Moremazda (Ryan, right?) did his like that ;).

the question is can you put up with the oil leak?
Well, I probably could put up with the leak, but its the JB weld thats scaring me. I wiped it down with a rag the other day and a chunk came off. Im just afraid that one day its all just gonna come out or blow out or something and make a huge mess, not to mention run my engine out of oil in a matter of seconds. With my low oil sensor not working, I dont need that.

or worst case senario if you do drill it out and metal shavings f**** up the motor, can you be without the car?
No :(.

~T.J.

TheBigOne 01-29-03 12:19 AM

Try this!
 
Weld a square piece of metal over it :)

Keaponlaffen 01-29-03 12:21 AM

or more JB weld :D :cool:

Rota_Motor 01-29-03 03:20 AM

just a thought,
am I right in thinking it is the oil pressure sender hole in the rear endplate that needs to be drilled, tapped and sealed??
to my way of thinking this shouldnt pose a problem if the metal shaving do get into the engine, well into the oil gallery there specifically.

OK assuming you are using the early air/oil type oil cooler, oil comes out of the cooler, thru the pipe, and into the rear housing via a banjo bolt at the bottom.

excess pressure is bled off thru the rerar pressure relief valve at the bottom, and the rest of the opil flows up thru the endplate.

then it flows past the pressure sender unit, which is where any metal shavings will be, and then onto and thru the oil filter and into the engine.

so try to keep as much as you can out of the engine of course, but if any metal goes into that opil gallery, I should think it would get washed up and filtered out anyway, although it would be an idea for a new filter before first starting to make sur it is clean, and change it after 50 miles or something so the metal thats caught doesnt go thru the engine.

inittab 01-29-03 06:31 AM

I don't have a loose end plate to look at but I'm sure someone here does. What exactly does it look like in that sender hole? Does is drop off down a tube or is there a ledge or something that might catch the shavings? You can build your strategy around how it actually looks. If there's a ledge where the shavings can rest, I would drill carefully then use a shop-vac to suck the chips out. When tapping do as others have suggested and use grease on the tap. I had to put a heli-coil in my one of my leading plug holes and that's how I kept chips from getting into the rotor housing. It worked perfectly! Good luck!

MikeLMR 01-29-03 06:46 AM

Its a 1/8th " BSP thread, as in British Standard Pipe

Its is a well know trick to screw an NPT fitting into a BSP tapping as the tapered fitting (Nation Pipe Tapered) will bite into the non tapered hole threads making a better seal than if it screwed into the tapered NPT hole

This trick has been used by industry for many years :)

85RX7GS 01-29-03 07:37 AM

Change the oil after you do this.

jeremy 01-29-03 07:50 AM


Originally posted by 85RX7GS
Change the oil after you do this.
:crackup: i think that summed it up.

also, is it necessary to drill and tap all the way through? all you need is 2-3 thread engagement. make sure you put some good sealent on it that can stand up to heat and oil.

Rx7carl 01-29-03 09:16 AM

I use a 1/8 npt fitting off that port on my motor for my oil press and oil temp gauges. I'd agree with draining the oil, dropping the pan, removing the reg. Then drill,tap, blow out the passage. Also spray some carb cleaner in then blow again. You dont want stray particles to stick to the passage from oil stuck to the side of it. When your satisfied its clean, re assemble. Plan on taking a whole day to do it so you dont rush the job. Do it once, do it right. Then you can sleep at night and not worry. Dont JB weld over it, you know sooner or later itll just start leaking again. remember this is under pressure, you need a good solid plug in that hole.

Pele 01-29-03 09:36 AM

Drill your hole... Then use a shop vac to remove as many of the shavings as possible... Finally, see if you can pump the oil without running the engine. Shoot the oil out of the drilled hole. (Perhaps remove the oil filter and stick compressed air to that... Or use compressed air down the filler or dipstick tube.) This way, the oil forces out all the shavings that the vacuum didn't get.

Finally, change the oil... There's bound to be some microscopic little particles that the vacuum, nor the oil stream didn't pick up. Some small shavings probably won't hurt much.. What do you think happens when engine parts wear out... That's why there's oil filters.

On the blowing the blowing the oil out of the engine trick... I remember when I first did an oil change on the RX.-7. I wanted to get ALL of the old oil out of the engine. I know theres a little sitting in the oil pump and in the passages. I really don't wanna crank it with no oil in the sump though... I know... I'll remove the oil filter and blow down it. But I don't wanna put my mouth on it... What's this... Craftsman 1/8 HP leaf blower - 200 MPH Air Velocity... That'll work... Vreeeeeeee... UGH... Now I gotta take a shower...

But like I've said before... Welcome to Bad Ideas 101... I'm your professor, Pele.

Rx7carl 01-29-03 10:53 AM

:rofl: Pele, as I was reading your post thats just what I was picturing. RMD covered in oil!!!!!!!

error402 01-29-03 11:13 AM

Pele, your not the only one who has tried that. It seems to be a good idea at the time. :D

That also reminds me of the time when I was draining the oil from my car, and it was taking forever to drain, so I blew down the oil filler neck...not realize that the oil was coming out with more force and totally missing the pan I had down there to collect the oil.


-Error

RotorMotorDriver 01-29-03 04:32 PM


Originally posted by Rx7carl
:rofl: Pele, as I was reading your post thats just what I was picturing. RMD covered in oil!!!!!!!
Thanks guys...:D

just a thought,
am I right in thinking it is the oil pressure sender hole in the rear endplate that needs to be drilled, tapped and sealed??
to my way of thinking this shouldnt pose a problem if the metal shaving do get into the engine, well into the oil gallery there specifically.

OK assuming you are using the early air/oil type oil cooler, oil comes out of the cooler, thru the pipe, and into the rear housing via a banjo bolt at the bottom.

excess pressure is bled off thru the rerar pressure relief valve at the bottom, and the rest of the opil flows up thru the endplate.

then it flows past the pressure sender unit, which is where any metal shavings will be, and then onto and thru the oil filter and into the engine.

so try to keep as much as you can out of the engine of course, but if any metal goes into that opil gallery, I should think it would get washed up and filtered out anyway, although it would be an idea for a new filter before first starting to make sur it is clean, and change it after 50 miles or something so the metal thats caught doesnt go thru the engine.
This is what I was thinking too last night.

I don't have a loose end plate to look at but I'm sure someone here does. What exactly does it look like in that sender hole? Does is drop off down a tube or is there a ledge or something that might catch the shavings? You can build your strategy around how it actually looks. If there's a ledge where the shavings can rest, I would drill carefully then use a shop-vac to suck the chips out. When tapping do as others have suggested and use grease on the tap. I had to put a heli-coil in my one of my leading plug holes and that's how I kept chips from getting into the rotor housing. It worked perfectly! Good luck!
I have one, just not at this house :(.

~T.J.

Rx7carl 01-29-03 05:22 PM

I was thinking youd look like a cartoon character LOL.

SO I took the time to dig you up a housing and inspect it. Theres no real ledge. The port goes straight in and meets the passage up from the rear regulator and your new oil supply inlet (with your air oil cooler thats now the supply line). Yes the next stop for any chippies that go down the hole will be the oil filter. But remember, at start up, most all filters bypass valves open cause the oil is cold. So your taking a chance. Look if it hasnt blown out yet, plan a day to do it right (like a weekend) and drain the oil (hell you could even re-use it if you drain it into a clean container). drop the pan, remove the reg, disconnect your rear oil hose (dont worry the crush washers are usually good for at least 3 or 4 re-usese). Do your drilling, tapping, yadda....... Then flush the passage with carb cleaner to remove chips and contaminated oil. blow it out good. And then your set. Its the best you can do the job.

RotorMotorDriver 01-29-03 06:13 PM


Originally posted by Rx7carl
I was thinking youd look like a cartoon character LOL.

SO I took the time to dig you up a housing and inspect it. Theres no real ledge. The port goes straight in and meets the passage up from the rear regulator and your new oil supply inlet (with your air oil cooler thats now the supply line). Yes the next stop for any chippies that go down the hole will be the oil filter. But remember, at start up, most all filters bypass valves open cause the oil is cold. So your taking a chance. Look if it hasnt blown out yet, plan a day to do it right (like a weekend) and drain the oil (hell you could even re-use it if you drain it into a clean container). drop the pan, remove the reg, disconnect your rear oil hose (dont worry the crush washers are usually good for at least 3 or 4 re-usese). Do your drilling, tapping, yadda....... Then flush the passage with carb cleaner to remove chips and contaminated oil. blow it out good. And then your set. Its the best you can do the job.

What if I got the engine hot first, burned myself while working on it, then started it and the oil would hit the filter and catch any "nasties"? Or, if I went the whole take it all apart route, why couldnt I just take the line off the fitting and flush it? Why do I have to take the fitting off and try and re-use the crush washer?

~T.J.

Rx7carl 01-29-03 06:23 PM

DOH!!!! yea just unscrew the hose. Well I feel your taking a chance if you dont take it apart. It wont cost anything to do it that way other than time right? so why not take every precaution?


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