Page 1 of 1
J pipe too close to head
Posted: Tue Jun 02, 2015 5:07 pm
by weldvair
My engine builder put J pipes on my engine....one of them is about 1/16" below the head & the other is about 1/8" below. I do not know where he bought them but, I feel they are to close to put heat shields on them......are there ones made that drop further below the head?
Don
Re: J pipe too close to head
Posted: Tue Jun 02, 2015 8:45 pm
by sideshow
I have observed that the more expensive J-tubes have a shape that follows the heater box innards. They drop away from the head and lack the shell for the heat exchanger. CSP has a good example
http://www.csp-shop.com/products/Produc ... 5922c/det/
Cheap J-tubes seem to be a straighter design, I have never measured nor cared much. Just try to stop buying cheap crap.
Re: J pipe too close to head
Posted: Wed Jun 03, 2015 4:16 am
by weldvair
I did not buy them my engine builder did. Does anyone know where I can
buy USA made that drop away from the head like the one shown ....in steel
not stainless? I want to weld on it so mild steel is better for me.
Don
Re: J pipe too close to head
Posted: Thu Jun 04, 2015 2:55 am
by weldvair
can not find any so I will make it......Don
Re: J pipe too close to head
Posted: Thu Jun 04, 2015 7:35 am
by FJCamper
Hi Weldvair,
The fix for too-close J-pipes -- which transfer heat to the head -- is to cut a simple sheet metal heat shield that is fastened to the J-pipe.
Cut the shield as a rectangle, and notch it so stainless steel hose clamps will hold it to the top of the pipe so it is between the pipe and the head.
This works very well.
FJC
Re: J pipe too close to head
Posted: Thu Jun 04, 2015 9:43 am
by Marc
You might also try loosening the nuts on the exhaust flanges and see if the tubes will shift downward a little. Or (with the nuts tight) remove the header and insert a jackhandle into the J-pipes and tweak them down slightly....a ΒΌ" clearance should be enough to allow for heat shields.
Gas-heater Things come from the factory with undercylinder tin designed for J-pipes, you'll probably want to emulate them.
Something like this:
http://i144.photobucket.com/albums/r173 ... G_0134.jpg ....'cept I'd use a softer radius at the top so there'd be less chance of denting the pushrod tubes if something ever smacked up on the bottom.
Re: J pipe too close to head
Posted: Thu Jun 04, 2015 10:56 am
by Max Welton
I think the j-tubes sold by Berg clear correctly.
Max
Re: J pipe too close to head
Posted: Fri Jun 05, 2015 6:18 am
by weldvair
I got them so I have a little more clearance....I will now make shields like Mark showed....thanks
for every ones help.
Don
