just wondering is it possible to get a stroker kit for a 4.1 250 Xflow motor, is there any benifits of stroking the 250 motor or it boaring a better option?
Ther used to be a kit which took the 4.1 to about 280 c.i , but really to me it seems ridiculous. The 250 already has a long stroke- 99 mm - and has trouble making much power past 5000 rpm. You can't bore the motor much, as you end up having trouble with head gaskets, cracked bores, etc. The less boring the better. Just work on good cam, compression, exhaust, intake,etc with a N/A eng. , or spend the big dollars and go for a turbo or blower. Lower gearing will also help acceleration a little....
I'd like to see more about the 280ci stroker. How much was it ???
I rang Quick 6 Performance and COME and they said it couldn't be done and it was not worth it. "It would cause inherrent vibration, etc, etc"
I believe anything can be done but at a price ???
You have to pay to be different !!!
i c tagsxf on the forums here has a set of pistons for sale for the Xflow motor which use the 200ci rods on these pistons do u think it would be the way to go
I believe using the 200 rods and custom pistons actually de-strokes the engine. Better if your going to rev it high but really needs a turbo to help wind it up!
A stroker wouldn't be worth the money because of the reasons listed above. After investing all the cash in making a custom stroker setup all you'd have is an engine that couldn't rev past about 4500rpm and although the torque would be nice, it would get thrashed by even a small turbo on a well prepped standard engine.
There was a thread around somewhere about boring the block about 120thou over and having custom pistons made to suit. Would get about 278ci.... expect to go through a few blocks to find one that would take such an overbore and it wouldn't be the greatest for a few things but should be a fair bit cheaper than stroker crank!
Safely? most blocks will take a 30 thou overbore, after that it can get close in places.
My XF was rebored and the block cleaned up. Crank reground, new pistons, whole assembley balanced, head ported and oversize valves installed, big cam, new lifters and valve springs, good set of extractors and a redline 4bbl intake with a 465 holley.
The HP is not this engine's big mover, its the big flat torque curve that climbs to 440nm at 2500rpm (when the converter locks up) and slowly moves up to 460nm at 3100rpm (peak) then slowly drops off to 440nm around 4200rpm.
The engine is still pumping out just over 400nm when peak HP is reached but it drops off quickly after that. This is looking at the RW dyno print out.
Check your block. I think XE and XF are stronger with more webbing round the mains and possibly thicker bores. Most make pistons up to 0.040" but I think ACL make a 0.060" set. I used 0.020" Precision cast pistons n cast rings.
150hp is only 112kW. Is that flywheel or rear wheels ???
Quote:
Originally Posted by blueovalxfboy
so wat size could u bore a 4.1 block to with out running any risks wit cracking cylinders also how do u get 150 hp out of ur xf
150hp is only 112kW. Is that flywheel or rear wheels ???
115KW by my calculations but not much difference.
I'm talking RWHP/KW. The engine would be good for a low 15 or even a high 14 in a sedan.In the porky station wagon a 15.5 is about the best I can hope for!
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
Linear Mode
