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View Full Version : 2001 XJ stroker build: keep 0331 head?


anthrax323
December 4th, 2017, 11:54
My 2001 XJ made it 240,000 miles before breaking a piston skirt. I can say with 99.999% confidence this is the original 0331 head (non-TUPY), as I've owned it since ~110,000 miles. Never had a single issue with it.

Given that it made it this far, is it reasonably safe to assume that I have one of the good 0331 heads? Or should I plan on locating a TUPY or other aftermarket head as part of the build?

tech1001
December 4th, 2017, 13:17
If your building a stroker you want more power , I would look at a performance head to add to the power . the stock head is not good for performance even if you do a PNP on the head , the after market head was made to flow better to start with .

smokeyyank
December 4th, 2017, 13:37
I'd swap it. No sense in building the rest of the engine and having to worry about possible head issue.

lazyxj
December 5th, 2017, 09:13
If your building a stroker you want more power , I would look at a performance head to add to the power . the stock head is not good for performance even if you do a PNP on the head , the after market head was made to flow better to start with .

Check with Russ Pottenger, he can do wonders with a 4.0 head, no matter if it is a 7120, 0630 or a crack free 0331.
He recently supplied forum member RCP Phx with a built 0331 head, along with a stroker kit.
Read about it here. It's quite powerful.
http://www.naxja.org/forum/showpost.php?p=246520043&postcount=108

RCP Phx
December 5th, 2017, 09:19
I sent Russ a new CCH 0331 head that's supposedly like a TUPY head.
https://www.amazon.com/gp/product/B014E3RN9Y/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

tech1001
December 17th, 2017, 14:00
Did you ever decide what head you were going to use ?

anthrax323
December 18th, 2017, 21:37
Not yet - Clegg is offering me a 17k mile TUPY head off a customer rig for $380 shipped (surfaced and cleaned up), which is hard to turn down... but the tiny-ass 0331 exhaust ports are making me think more about it. Apparently the performance head sold by Titan and a few others (around $700) is actually pretty damn solid and breathes a hell of a lot better. That's what I'm leaning toward at this point.

The 232 crank arrives on Wednesday (decided to build a ~4.2 mini-stroker), and the pistons by the end of the week, so I need to decide soon.

anthrax323
December 19th, 2017, 14:34
Another question: should my connecting rods be re-usable even after 240,000 miles? Being a mini-stroker, the geometry will only be slightly off from stock (~0.100" longer stroke).

RCP Phx
December 19th, 2017, 16:13
Not without rebuilding, do the pistons account for the stroke?

anthrax323
December 20th, 2017, 12:28
Nah, I'll be using a crankshaft out of an AMC 232 (3.500" stroke instead of 3.400" stroke). Stock 4.0 rods, bored .040" over, Silvolite 2229 pistons.

The block is at the machinist as of yesterday being hot tanked, bored, and having the mains inspected to see if it needs line boring.

When you say "not without rebuilding", do you mean replacing the studs? Rod bearings will be brand new as part of the build, as will wrist pins. Do the 4.0 rods have wrist pin sleeves/bushings? I'm guessing that since they're press-fit, that's a negatory.

RCP Phx
December 20th, 2017, 12:33
Stock rods are press fit, but the rod gets re-sized at the big end and anything else when rebuilt. Good rods/pistons like from Russ are machined with a bushing as a "free-floating" pin.

anthrax323
December 20th, 2017, 12:52
Why resized? You mean as a result of use for 240,000 miles? I can't just toss new rod bearings in?

RCP Phx
December 20th, 2017, 15:45
Nope, the big end usually elongates!