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I don't recall roller rockers as being inherently noisy? But, indeed, the need for them is another subject.
I had a set of comp's premium priced steel roller rockers... very noisy.
Then I tried some scorpion roller rockers... much quieter with a much lower price but they are fat and had clearance problems with my valve covers.
Then I tried an old fashioned set of stamped steel, same noise as the scorpions. Back to the rollers which are very necessary... IF...you have an agressive cam with high lift, very quick ramps and high spring pressure in the heads. The cam I'm running has the fastest ramps appropriate for a street cam and is noisier that a stock cam. I'm running AFR heads and springs. AFR heads comes with springs on the stiffer side of the range which further necessitates the need for roller rockers.
So in my case roller rockers are necessary and they are always necessary with a high lift cam becasue the pivots ball on OE stamped steel rocker is not designed for the orbital travel of a high lift cam. With stiff springs and high lift the stamped steels would probably fatigue crack and gaul on the fulcrum becasue of the high lift. When running high valve spring pressures there is so much friction at the fulcrum the rocker can over heat and crack in half.
Last edited by icsamerica; 02-17-2017 at 06:49 PM.
I feel your pain! Awesome car though, I can't believe how fast you made this happen.
Thanks, I've got 2 other coupe projects I'm gathering parts for.
1. A XJC with the last and best Jaguar v12, the 6.0L with distributor-less ignition. This one is going to have a heavy focus on refinement, and quietness, and less on all out performance. Still should be be very capable with wide 16 inch tires, a rear sway bar and and outboard rear brakes.
2. A late XJS V12, going to be properly stanced, braked, and converted to a 6 speed with a rear sway bar. Got the car, waiting on the bell housing.
The car drives so well I'm going to invest more in the finishes and fine details.
The chassis stiffening has improved the car so much it feels very contemporary. I've had the opportunity to give some of my car enthusiast friends a ride in the car and they are all amazed with the performance and refinement.
Need to refinish the dash and ski slope to match.
Gotta get some new contemporary gauges.
Need to finish the headliner and trim around the glass inside and out. Install sun visors and Gentex auto dimming rear view mirror
AIR BAG is functional. I even tested it by accident. My ears are still ringing.
Got some new tires 255/50/17 ultra high performance Nitto 555 all around. Amazing... it still has a compliant ride, handing and road holding is astonishing. Slight rubbing on dipps when the wheel is turned, a fender lip roll should help. Wont go with a smaller tire the performance it just too good.
Been driving it daily.
ABS works a treat! Heated seats, memory seats, dipping mirror, modern climate control.
Road holding and driving dynamics are amungst the best I've ever experienced. I have total admiration and respect for those Jaguar engineers who developed this chassis and suspension in the late 60's. So good that Aston Martin used it until 2007. That 40 years, mostly unchanged.
Small block with Northstar DIS is much more refined than I expected.
Last edited by icsamerica; 02-25-2017 at 08:07 PM.
Certainly needs to be lowered. I dropped lots of weight with this project and will try XJS rear springs. The coils on XJS springs are .5mm thinner and have 1 fewer coil than the springs that are in there now. The spring in there now might from a sedan.
Anyone know the exact lb/in on coupe springs? I calculated 250 lb/in based on coil diameter, coil count and wire thickness.
This could be a high 11 second car with a dead smooth idle. I cant use more than 1/2 throttle up to 40mph and I let off early because speed was excessive. Transmission is shifting a bit late too. Managed 12.9 on my first run. Great way get milk. Cant wait to make some adjustments and get to a real track.
Last edited by icsamerica; 03-07-2017 at 12:51 AM.
I've been daily driving this project and the 1 inch MC bore requires a bit more pedal effort that I like. It is very responsive and quick but almost touchy. This is perfect for high performance driving....but pedal effort is a bit grating on my sometimes traffic laden commutes. So... Back to the parts bin to trade in my 1 inch bore for a OE sized 15/16. The Mitsubishi Eclipse Master cylinders comes in three different bore sizes depending on whether or not they had ABS, were non ABS or had a turbo. Conveniently they are available in 7/8, 15/16 and 1 inch piston bore sizes. These choices allow a customized feel for whoever want to do this. Want less pedal effort go with a 7/8, OE feel then choose the 15/16, want more pedal effort but reduced travel, then the 1 inch. The bore size is cast as a number on the under side of the piston bore.
If you've been following this project you know I upgraded to a Mitsubishi Master cylinder form 1993 Eclipse but I found a better match. The 1997 Eclipse has the correct bore booster interface bore size and fits with great precision in the XJ6/XJ12/XJS booster. The 1997 eclipse also has a remote reservoir with Japanese engineered and reliable fluid level sensor. I bought the 1997 eclipse unit off of ebay strictly for the remote reservoir but when I got a closer look I noticed an opportunity. It's a better fit over all.
The 1997 MC has fluid adapters that fit straight up but the booster interface bore size is perfect. The 1993 has fluid adapter that are at a good angle but the booster bore size is not correct. The 1997 MC is a better option for retrofitting and is available in both 15/16 and 1 inch piston bore sizes.
The solution for for my needs was to use the 1997 MC and transfer the 1993 fluid nipples. They fit with a bit of trimming.
To install...
Both the MC's will need their bolt holes drilled out to 7/16 so it will bolt up to the vacuum booster.
The piston rod will need to be adjusted. The tip will need some grinding along its circumference. No grinding is necessary on the face of the rod.
See pict.
New fluid lines will need to be made as with Metric on the MC side and what ever the Jaguar is on the other. I dont know becasue I replumbed the whole car.
1997 Mitsubishi Eclipse MC with 15/16 bore found on Ebay with Reservoir and level sensor for 27$ free shipping.
Adjuster rod bolt ground smooth around the sides and bolt holes drilled out to 7/16
1997 MC with 1994 fluid nipples installed and under going bench bleeding. Very VERY important to bench bleed. Takes time, tapping and pumping to get all the air out of the MC. Notice how the rearward fluid nipple faces just so there is room for the fluid line to go around the boosters vacuum line as if it was made for it.
Last edited by icsamerica; 03-13-2017 at 12:38 AM.
Just got back from an longish test drive. Made improvements. Old exhaust was 2 inch in quiet mode and 2.5 inch in loud mode. It wasn't that quiet in quiet mode and it wasn't that loud in performance mode but it did have a drone and resonance that was noticeable.
Now The quiet side of the dual mode exhaust is now all OE with 1 3/4 inch tubing and 4 mufflers. It's dead quiet with no drone and no resonance. So quiet that there is no exhaust note to be heard. In loud mode it's 3 inch and has a very noticeable sound. A few open throttle blasts seem to indicate I've got some more top end power now.
G force data from the testing I did last week showed the acceleration slowed significantly just before the 1-2 and 2-3 shifts indicating the transmission is shifting 300 RPM too late. So rather than try to get the transmission to shift 300 RPM earlier, I'm trying to help breathing so the engine extend its RPM range and can still make power before the shift. Seat of the pants says job well done. I'll be testing with instruments as soon as the weather clears up and air temps return to where they were for the last test.
As for the brakes with the 15/16 MC... they feel more natural and less Porsche like. That special touchy caffeinated feel is gone. I missed it during my evening performance run. I wont miss it tomorrow when I'm sitting in slow moving traffic.
hey icsa, i was thinking about a slightly different type reservoir!
some place on net a picture of a two outlet push on res. it did not use a remote system,
a much simpler set up , it was very low so did not stickup and hit the hood!
my Ford truck MC works fine 15/16 bore, a bolt in mod.
but when messin around in that area have started some small weeping leaks from the res. hoses! annoying.
Move that air intake cleaner outside the engine compartment for some cool air.. will help performance... I have not tried my 1/4 mile performance yet on my new GPS speedo that records them... figure mid to high 13's due to 2:88 LSD now... but fuel mileage is 21.5 MPG at freeway speeds. Gotta feed them horses...
02-17-2017, 06:42 PM
