[xj40] performance camshaft

I’m trying to get more horsepower out of my 93 xj/40. Does anyone
know if performance camshafts are available? Parts people I have
spoken to so far have said there’s not much that can be done with
overhead cams. Could this be true?–
spc
cold spring harbor, United States
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SPC.
Of the shelf parts would be very few and far between,
I have seen a tape from the Jaguar factory, they produce a series called the
Andrew Whyte Lectures. There was one which gave sketchy details of an
individual who required more oomph from his XJ40. He eventually attained a
figure in the region of 450 hp with a combination of tuning and I think
Turbo charging, if you can find a copy it is well worth watching.
Best chance would be to talk to a performance shop about getting your
original cams re-profiled, A small amount of work can be achieved by
reducing the base lobe on the cam which can give a slight increase in lift.
or the top of the cam lobe can be re-profiled to increase the duration of
maximum lift by flattening off the top radius, or a combination of both,
reducing the base diametre and flattening the top will retain, within
limits, the lift and give a slightly longer duration.
I had a set of cams modified for my ‘S’ type way back in the eighties when I
was running it on compressed natural gas, they simply reduced the top of the
cam to hold the valves open longer at maximum lift. Even running on CNG I
could still tow a Mini Cooper around with out a problem.
The only down side to this was that the engine was a little clackey from the
top end.
BTW we do use real names on the list :slight_smile:
Regards Robin.----- Original Message -----
From: “spc” spc816@aol.com
To: xj40@jag-lovers.org
Sent: Sunday, 14 December 2003 6:41 a.m.
Subject: [xj40] performance camshaft

I’m trying to get more horsepower out of my 93 xj/40. Does anyone
know if performance camshafts are available? Parts people I have
spoken to so far have said there’s not much that can be done with
overhead cams. Could this be true?

spc
cold spring harbor, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting
services and resources including Photo Albums, Event Diary / Calendar, On
Line Books and more !

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SPC,
Please let us know your name as it is considered impersonal/harsh to
address a sudo.
In answer to your question, NO. The camshafts can be removed and sent
to many different cam makers to be reground into a different configuration.
I am not familiar with any aftermarket company’s at this point that offer
ready made cams for these cars. I can however state this: In 1982 I built
a 1500cc tri-case Porsche engine w/dual 40 Webbers in which no one offered
an aftermarket cam. Crane Cams of the USA reground the OEM cam at a
reasonable cost. The engine was a screamer but you must understand that
cylinder head porting, valve spring loads, and higher compression had to go
along with this cam to make it work properly not to mention timing curve.
A quick note of advise though, the horsepower gain you are looking for
may very well be more feasible using nitrous oxide due to fuel system
modifications that would need to be made with the new cams. A mild kit can
be installed to add 50-75hp without any internal modifications and only
minimum fuel mods.
Turbo-charging is another option. A turbo can be added with mild boost
(4 lbs max) without any major mods to the engine.
Changing camshaft geometry makes for a stack up effect where many other
modifications should be made as well to gain any real horse power advantage.
Not a real efficient or economical way to boost HP.
Best Regards,
Greg
“Scotlander”
90 VDP Majestic
91 Sovereign
63 MKII 3.8----- Original Message -----
From: “spc” spc816@aol.com
To: xj40@jag-lovers.org
Sent: Saturday, December 13, 2003 11:41 AM
Subject: [xj40] performance camshaft

I’m trying to get more horsepower out of my 93 xj/40. Does anyone
know if performance camshafts are available? Parts people I have
spoken to so far have said there’s not much that can be done with
overhead cams. Could this be true?

spc
cold spring harbor, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting
services and resources including Photo Albums, Event Diary / Calendar, On
Line Books and more !

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

Yes, there is a place called Terry’s Jaguar in Indiana that will sell
you a high performance hear with high performance cams or rebuild yours
including truing it up for squareness and cleaning out the exhaust
passages, relapping or replacing valves, seals and seats as needed.

No I do not have any association with Terry’s Jaguar but I did just
receive his catalog of parts and if you want to modify your Jag, this is
the best site I have seen in terms of what is available. If I knew how
to up load this site to the archives I would.

Just do a search on Terry’s Jaguar Indiana in Google and it should come
up. If you can’t find it write me off-line and I will give you there
site. He is not cheap but the modification seems to put one heck of a
HP gain on the engine ( I would not put this head on an engine with
200,000 miles on it without first rebuilding the engine. He also offers
complete rebuilt engines with the modified hear but I have no idea of
the price. As for any modification you make to improve HP be sure the
bottom end can take the addition or you will be one un happy camper.

Jay 90 VDP Majestic

spc wrote:

I’m trying to get more horsepower out of my 93 xj/40. Does anyone
know if performance camshafts are available? Parts people I have
spoken to so far have said there’s not much that can be done with
overhead cams. Could this be true?

spc
cold spring harbor, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !