Drill/tap hole for block heater

I bought a block heater from Sharp's that is 3/4 pipe thread & it screws into the bottom of the head. The drain hole on my head is 1/2 pipe thread. It looks like plenty of room to drill & tap a hole for this heater. Wha do you think?

From this picture which I took about 30 min. ago it looks like there is an insert. Anybody else see that? How could I remove it if there is indeed one in there that took it from 3/4 down to 1/2? This is the first time that I have seen this. I'll look more this weekend, no time now, homework.

Thanks

I know there's quite a bit of depth to that head/water fitting, but I don't have one lying around to measure. The heaters I found are as follows:

3/8" NPT 400 Watt element 2-3/4" long, #3500026

1/2" NPT 300 Watt element 5" long, # 8609659

If this is what has been done, and you drill the bushing out, you will expose the rusted-out 3/4 pipe threads.

I am almost certain Phillips-Temro makes a heater similar to the one you have that has 1/2 pipe threads.

If you would like, I can research this, and get you a part number. If, in fact they make a 1/2" pipe thread version, it shouldn't be too tough to get ahold of one, saving messing with the head.

I found their website but it doesn't have specific products, just categories, which engine pre-heaters was one.

Thanks
e-mail is open

In the paper catalog, (which I have at the shop), they have heaters listed by size, with photos.

If you can get in that far online, you can see what they have. Otherwise, I will look at the paper catalog tomorrow, and let you know what I find. A 1/2" unit sure would make things simple!

I'll see if I can find those .pdf catalogs.

Let you know if I need any more help.

Thanks

Can you scrape the paint to get a better idea, or go through the hole with a small pick, mirror, light, etc, to see if there is a ridge on the back side. Maybe this would help decide if it is for sure a bushing. A lot easier than tapping.

Rick

Keith & Shawn

Allan

Here

I see. I thought you were working with a tank heater. Back to your idea?

Allan