Coolant Crossover AN Conversion, Part List and Pictures.
05-06-2011, 11:01 AM
#23
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Nice write up .Some additional information .The head is actually threaded 1/4 npsf which is a straight thread ,the 1/4 npt will screw in and tighten up but I always run a 1/4 npt tap in first so that you have a proper seal. You should also use steel fittings in the heads as when you use aluminium you are putting 2 of the same materials together and the chance of galling is greatly increased and screwing up the head.JMHO.
Parts run! 
12-29-2011, 11:14 AM
#25
Can't imagine trying to tap the rear of the heads and get all that pluming together back there. I imagine someone could do it, but I hope it is never me
Al 95 Z28
12-29-2011, 11:41 AM
#26
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FYI using A/C conditioner flat seals will work to seal the tube and bolts. They cost about 1.25 each. As for removing the bolts a ratchet wrench works the best and to tap it a Snap on thread chacer works perfect in the tight in car area.
I do like the way this was done but SS line would set it off.
I do like the way this was done but SS line would set it off.
12-29-2011, 01:10 PM
#27
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FYI using A/C conditioner flat seals will work to seal the tube and bolts. They cost about 1.25 each. As for removing the bolts a ratchet wrench works the best and to tap it a Snap on thread chacer works perfect in the tight in car area.
I do like the way this was done but SS line would set it off.
I do like the way this was done but SS line would set it off.
01-02-2012, 08:17 PM
#29
and a HUGE number of people like to "save" a little where it would make a big performance difference, and spend a lot where it doesn't.
If someone were to do this for aesthetics I would think you could just replace the section that runs along the intake and save a handful of fittings.
On a b-body the upper bellhousing bolts are easily accessed with a ratchet wrench from the top, looks like this would make that harder.
If someone were to do this for aesthetics I would think you could just replace the section that runs along the intake and save a handful of fittings.
On a b-body the upper bellhousing bolts are easily accessed with a ratchet wrench from the top, looks like this would make that harder.
01-02-2012, 09:34 PM
#30
A for price, i used some brass fittings, hose clamps and 3/8 hose.
cost me only about $10 and no leaks. runs 180* all day in stop and go traffic in az heat..
AN line may look better but ive got no problem with one blaco hose next to my intake. its hidden by all the wiring BS anyways
cost me only about $10 and no leaks. runs 180* all day in stop and go traffic in az heat..
AN line may look better but ive got no problem with one blaco hose next to my intake. its hidden by all the wiring BS anyways
01-02-2012, 11:54 PM
#31
[QUOTE=96capricemgr;15792970]and a HUGE number of people like to "save" a little where it would make a big performance difference, and spend a lot where it doesn't.
/QUOTE]
Well Dwayne, you're the genius around here so I guess whatever you say goes. Yep.
/QUOTE]
Well Dwayne, you're the genius around here so I guess whatever you say goes. Yep.
01-03-2012, 09:59 AM
#32
and a HUGE number of people like to "save" a little where it would make a big performance difference, and spend a lot where it doesn't.
If someone were to do this for aesthetics I would think you could just replace the section that runs along the intake and save a handful of fittings.
On a b-body the upper bellhousing bolts are easily accessed with a ratchet wrench from the top, looks like this would make that harder.
If someone were to do this for aesthetics I would think you could just replace the section that runs along the intake and save a handful of fittings.
On a b-body the upper bellhousing bolts are easily accessed with a ratchet wrench from the top, looks like this would make that harder.
08-21-2012, 11:22 PM
#34
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GM part 12556260 - steam crossover Its $73.93 from Scoggin Dickey Parts Center.
http://sdparts.com/details/gm-factor...parts/12556260
Tom
http://sdparts.com/details/gm-factor...parts/12556260
Tom
03-03-2013, 03:08 PM
#36
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I did this with brass fittings from home depot for about $30... didnt even dawn on me to use an stuf, facepalm... This is a little nicer looking but same exact concept. Soooo much more convenient than the original steam pipe deal with dumb banjo bolts and washers...
03-03-2013, 10:06 PM
#37
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if you dont want to pay alot for a replacement line and yours is messed up, i can maybe understand trying to do something different. but the stock hardpipe is a good design and cant see doing away with it for a half dozen fittings and a hose that could potentially leak.
03-04-2013, 06:32 PM
#38
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Well, my original line looked like it had been bent/kinked a few times and both banjo bolts looked corroded on the threads. Dealership told me the bolts are discontinued... then, even if I opted to clean them up nd reuse them, the damn washers from the dealer were about $8/ea.. a new steam pipe setup at dealer was over $100. Sooo... knowing that all the parts i am now using are easy and cheap to replace as well as it provides me with easier access (with the way I set it up). Brass fittings, standard 3/8" heater hose, and stainless hoseclamps and thread sealer on all the stuff... havent had any leaks yet.
Edit : Not advocating that its better or a performance gain here... although... looking at the stock tubing and smaller holes in the stock banjo bolts, this setup might allow a little more coolant flow over stock and be less likely to clog up (if thats even a concern). The banjo bolts that were in my car looked pretty cruddy up in the holes. Dont know if previous owner did a bunch of stop leak or what.
Edit : Not advocating that its better or a performance gain here... although... looking at the stock tubing and smaller holes in the stock banjo bolts, this setup might allow a little more coolant flow over stock and be less likely to clog up (if thats even a concern). The banjo bolts that were in my car looked pretty cruddy up in the holes. Dont know if previous owner did a bunch of stop leak or what.
Last edited by hyperzone; 03-04-2013 at 06:45 PM.
04-18-2013, 10:50 PM
#39
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I just did this on my motor while it was out, and I should not if your not careful when putting the motor back in the elbows will hit the firewall and bend. Changed my chain setup on how I hooked the motor and no more problems getting it in, but it's a real tight fit back there. I'm very happy with this mod!
03-24-2017, 01:39 PM
#40
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Not 1/4 NPSF threads Thought to share a little more info for the next guy who's doing this:
The stock threads in the back of the heads are NOT 1/4 NPSF. They do seem to be straight threads, but I'm guessing are some metric dimensions.
I bring this up because I thought instead of using a 1/4 NPT, I bought 1/4 NPSF to AN fittings. Apparently then I wouldn't need to bother with tapping the heads. Incorrect. The 1/4 NPSF fittings will not fit into the heads. I still had to buy a 1/4 NPSF tap to be able to thread the fittings into the heads. I've attached pictures showing the measurement differences between the 1/4 NPSF fitting and the OEM banjo bolts. The 1/4 NPSF fitting major diameter is 0.020" larger and has a 0.010" larger minor diameter. As you can see, the OEM threads do not have the allowance for 1/4 NPSF fittings. And after tapping with 1/4 NPSF, the OEM banjo bolts feel significantly looser for installation.
To be clear:
I'm not saying using the 1/4 NPT fitting is a bad idea.
I'm not saying you shouldn't use a 1/4 NPT tap instead.
I'm only pointing out - that if you think you could just buy 1/4 NPSF to AN fittings, unfortunately, you'll still have to tap the heads.
The banjo bolts having a 15 mm head further suggests the threads are metric. The OEM thread pitch is pretty close to 1/4 NPT or NPSF though. Your call with what fitting to go with. Good luck.
The stock threads in the back of the heads are NOT 1/4 NPSF. They do seem to be straight threads, but I'm guessing are some metric dimensions.
I bring this up because I thought instead of using a 1/4 NPT, I bought 1/4 NPSF to AN fittings. Apparently then I wouldn't need to bother with tapping the heads. Incorrect. The 1/4 NPSF fittings will not fit into the heads. I still had to buy a 1/4 NPSF tap to be able to thread the fittings into the heads. I've attached pictures showing the measurement differences between the 1/4 NPSF fitting and the OEM banjo bolts. The 1/4 NPSF fitting major diameter is 0.020" larger and has a 0.010" larger minor diameter. As you can see, the OEM threads do not have the allowance for 1/4 NPSF fittings. And after tapping with 1/4 NPSF, the OEM banjo bolts feel significantly looser for installation.
To be clear:
I'm not saying using the 1/4 NPT fitting is a bad idea.
I'm not saying you shouldn't use a 1/4 NPT tap instead.
I'm only pointing out - that if you think you could just buy 1/4 NPSF to AN fittings, unfortunately, you'll still have to tap the heads.
The banjo bolts having a 15 mm head further suggests the threads are metric. The OEM thread pitch is pretty close to 1/4 NPT or NPSF though. Your call with what fitting to go with. Good luck.