If your interested im makeing a camshaft upgrade in my 4.0 xk8, foumd a guy in alabama whose being doing shafts for years. I will send the shafts to him, he can reweld the shafts then upgrade the duration and lifts to give up to 15% more power. Spoke to him and he sounds like he has lots of experience with jaguar perfformance camshafts. Has already done a couple of xks . Couldnt find anyone who sells them but this guy If anyone has any info on someone else get back with me. Roughly 43 more horses . Ive done that in chevys before so i know that its real , so only thing to do is get them to him and see if it will work on jaguars...

 

i know a different company/guy from the BMW world but do you know your guys prices?

I'll pull some xj8 heads and use them as cores for a good price

 

This sounds interesting. Are there any downsides, such as increased potential to damage your engine, that could result from such a mod. Also, what does this guy charge? Has anyone done this mod?

Mark

 

he charges 500.00 to do all 4 cams, turn around time is 3 weeks, can your guy do this any faster. if so give me a way to contact hiom. and what did he tell you about horsepower gains. i would love to hear what gains he could give..

 

ive done them in my american cars many times before, valve to piston clearence is something to watch. but with the compression in a 4.0 of10.8 he feels that thier is plenty of clearence... also says
that the factory camshaft is a very moderate cam , so increases to what is already thier can really help increase power with no problems

 

I think this just made the top of my list for next years mods. Can you pm me his contact info? Thanks,

Mark

 

Is this being done without remapping the ECU? I would think it would be necessary to advance the ignition timing and increase the fuel injection.
RJ________________
97XK8 86K mi

 

[QUOTE=rsigue;594656]If your interested im makeing a camshaft upgrade in my 4.0 xk8, foumd a guy in alabama whose being doing shafts for years. I will send the shafts to him, he can reweld the shafts then upgrade the duration and lifts to give up to 15% more power. Spoke to him and he sounds like he has lots of experience with jaguar perfformance camshafts. Has already done a couple of xks . Couldnt find anyone who sells them but this guy If anyone has any info on someone else get back with me. Roughly 43 more horses . Ive done that in chevys before so i know that its real , so only thing to do is get them to him and see if it will work on jaguars...[/QUOTE

Are these cams a straight bolt on with no mods required, just install the cams & readjust the valves?

 

If it is a welded on solution, and you leave the stock diameter, it can be a straight fit. But $500 for a welding job seems very low in price for 4 cams, and without changing the diameter you might be limited in the lift you can create.

Contrary to a re-grind job, then the price sounds more ok, but then as you de-crease the diameter, you need lash caps to compensate.

 

I used to run a PCM tuning service on the side a few years back; based on my experience a cam change will need to be tuned, it's a significant enough change where the parameters fall outside of the regular PCM programming and the PCM just can't adjust itself. That said, I have never tuned a Jag PCM, though I suspect my reasoning holds true regardless.

If it is a mild cam the vehicle might run, but poorly. If it is a more aggressive change, the vehicle might not even run without a tune. This effect is compounded when you throw forced induction such as an XKR supercharger in the equation.

I'd definitely be interested in seeing someone bite the bullet on this and give it a try!

 

Well, I already did, have done a mild change via a re-grind, and no ECU adjustments are needed. Don't have any before and after dynos, but I did see an increase in airflow, somewhere between 3 and 5% gain, that usually also translates in the same power increase.

 

If his guy has already done this for a couple XKs he should know if PCM tuning is needed or not (and it sounds like it is needed) and if so, can he do the PCM tuning or does he know where it get it done?

Mark

 

I have reground cams on my car & run a stock ecu tune with no issues.

 

need not be done. the new cams will not need a ecu tune. The ecu will need to be disconnected so it can learn what the new cams like , Just the same as when we ad a cold air intake, or we change muffler systems, this is all we need to do. Its simple guys just have to spend the money to get the cams redone..Again factory puts smaller cams into this motor so that they can pass emissions and fuel regs. Ive had my ecu retuned and felt that i wasted money, Power band was way too high , no bottom this a way to aDmore horsepower to this engine , its the one that we have and perfer to make more powerful . Instead of selling it and buying an R.....If u want more bottm end all we have to do is change the rear end gears from the 3.06 to a 3.46 this will give us some ump and may be we could spin a little tire ,. this is what i want in my xk8 so i will under take this project and let you guys know how its comming out...MY LITTLE SLEEPER SMOOTH ON THE HIGHWAY BUT A REAL CAT AT A RED LIGHT!!!!

 

That's great. I'm looking forward to hearing about your experience. That's a lot of power to add just by changing cams.
RJ_____________
97XK8 86K mi

 

[QUOTE=rsigue;595750]need not be done. the new cams will not need a ecu tune. The ecu will need to be disconnected so it can learn what the new cams like , Just the same as when we ad a cold air intake, or we change muffler systems, this is all we need to do. Its simple guys just have to spend the money to get the cams redone..Again factory puts smaller cams into this motor so that they can pass emissions and fuel regs. Ive had my ecu retuned and felt that i wasted money, Power band was way too high , no bottom this a way to aDmore horsepower to this engine , its the one that we have and perfer to make more powerful . Instead of selling it and buying an R.....If u want more bottm end all we have to do is change the rear end gears from the 3.06 to a 3.46 this will give us some ump and may be we could spin a little tire ,. this is what i want in my xk8 so i will under take this project and let you guys know how its comming out...MY LITTLE SLEEPER SMOOTH ON THE HIGHWAY BUT A REAL CAT AT A RED LIGHT!!!![/QUOTE

I have changed rear end gears as well, if you install a 3.58 you will increase your acceleration. If you want a real sleeper you can get a 4.09 pozi to bolt in. This will give you a real sleeper. You will probally top out around 145 mph & loose quite a bit of fuel mileage.

 

Where can i find the ring and pinion gears and how hard was it to change them. Ive changed gears in the old camaro but this is a different animal, and what is the cost of the ring and pinion

 

You need a complete diff assy. & a mounting bracket fron an XJ6. I will the bolt right in with the only mod required being relocating the exhaust hangers from yours for the axle pipes.

 

ebay here i come, saw one on there today

 

I put new ring and pinon gears in my rear dif as well as an LSD. The expensive part is that you need a new/re-programmed transmission control module or it will not run (cost about $2k).

That said, I am very interested in this cam upgrade and will be following this thread closely. I'm just finishing up my mods for this year but want to do this cam upgrade, supercharger porting and pulley upgrade (1.5 psi so no snout grinding) next year. Altogether, this will add about 100 hp, which is all I want. Keep us posted, thanks,

Mark