The wacky engine conversion thread

[Spectre]

That's why German and American corporations have millions of dollars (well, not the Americans anymore) and Jaguar has never made much money: They used sheap-to-build swing axles instead of spending the money to build a proper IRS like the one in your picture.

Incorrect. The Jag IRS shook the motoring world because it was the first true IRS offered to the motoring public at an affordable price. Competing systems cost two or three times as much if not more. In fact, it wasn't until much later that GM managed to get the Corvette's IRS down to the point where it was comparable. The price to build the Jag IRS isn't that much more than it is to make a swing axle.

The Jag IRS is quite literally constructed out of almost all off-the-shelf parts. The diff is a Dana 44 out of a US light truck, the lower control arms are basically plumbing pipe, the upper control arms are also the halfshafts - and are shortened truck units made by Spicer (with common American truck/car U-joints). The only "custom" or "expensive" parts are the hub carriers, and those really weren't all that expensive to make anyway.

It is telling that Jaguar had a higher per-car profit margin on the E-Type than Chevrolet did on the C2 or C3 Corvettes it competed against, even though for most of the run the E-Type was often *cheaper* than the Corvette.

GM did, eventually, get the hint.

Yes, by ripping off the Jaguar design and slightly altering it. For some reason, they didn't like the inboard brake idea.

 

[thedguy]

But one of my favorites was a Honda CRX one of my high school friends built. He took the turbocharged 2.2 Mitsubishi from a Shelby Charger and mounted it mid-ship in the CRX! Brilliant! It won a lot of drag races at the import shows too. In fact, he got disqualified from an event for having an "American" engine, and beat it by proving it was a Japanese Mitsu engine. Ah, good times... good times...

The only thing Mitsubishi in any Shelby Dodge was the turbo

Yes, by ripping off the Jaguar design and slightly altering it. For some reason, they didn't like the inboard brake idea.

Shot in the dark, but aren't inboard brakes a PITA to change rotors on?

 

[Leonidae]

The only thing Mitsubishi in any Shelby Dodge was the turbo



Shot in the dark, but aren't inboard brakes a PITA to change rotors on?

Yes, quite large PITA actually. That's why hardly no-one uses them anymore.

 

[Spectre]

Shot in the dark, but aren't inboard brakes a PITA to change rotors on?

Yes, quite large PITA actually. That's why hardly no-one uses them anymore.

Well, they're not exactly *easy*, but if you have a lift and know the trick, you can replace the inboard rotors in about three or so hours from start to finish without dropping the rear subframe.

On the plus side, swapping pads is trivial (I have literally swapped both sets of pads in less than three minutes using no jackstands and no tools other than a pair of ramps) and the massive unsprung weight reduction is, IMHO, worth it. It's amazing to follow a Series III in another low car on a rough Dallas road and watch the rear wheels moving around like mad under the back of the car (tracking the road, staying in contact) while the body stays perfectly straight and level. One of these days I'll fit a camera to the nose of Merp's Cobra and we'll get a video of it.

 

[thedguy]

Well, they're not exactly *easy*, but if you have a lift and know the trick, you can replace the inboard rotors in about three or so hours from start to finish without dropping the rear subframe.

Well that kind of says it all. That's with a fucking lift and knowing the "tricks"? I can see why Jag mechanics have $ signs in their eyes.

I'm sorry that is not a good design. Any consideration I had of buying a jag just went out the window (and took the house it was attached to with it!)

I'm honestly not sure I should laugh or cry after reading that post.

Why couldn't they have put on some kind of slip yoke and make it so you unbolt the flange from the diff, push the axle down the yoke, un-bolt the rotor and replace?

 

[Spectre]

Well that kind of says it all. That's with a fucking lift and knowing the "tricks"? I can see why Jag mechanics have $ signs in their eyes.

I'm sorry that is not a good design. Any consideration I had of buying a jag just went out the window (and took the house it was attached to with it!)

I'm honestly not sure I should laugh or cry after reading that post.

Why couldn't they have put on some kind of slip yoke and make it so you unbolt the flange from the diff, push the axle down the yoke, un-bolt the rotor and replace?

Well, the inboard brakes ended on the sedans after 87 and on the coupes/convertibles after the 1990 facelift. All of the XJ40-and-later designs are outboard rotor.

As for the slip yoke, that's exactly what you get if the nut comes off the end of the drive axle. Here's what *that* looks like.

Yeah. That slipyoke concept is not a good idea - remember, the driveshaft/halfshaft is also the upper control arm!

By the way, the three hours is only using hand tools. The trick is to get the thing in the air, disconnect the trailing arm and lower control arm (four bolts a side), then unbolt the flange from the diff and disconnect the driveshaft/upper control arm from the diff by unbolting it (four nuts). You then take out the shaft and hub carrier as a unit (because setting the preload on the carrier is a PITA). Then you can remove the calipers (four bolts per side) and pop out the rotors (rotors are held on by the shaft nuts). The reason you need the lift is because you need to get the car about 3' in the air to allow the lower control arms to droop enough that you can get the rotors out past them. You could do it with some really big jackstands, I suppose... With air tools, as in a shop, you're looking at *maybe* 90 minutes or so if you hustle. Most of that time is getting the #(*&$()#@&)#$@)(&$ calipers off because the bolts don't want to come out and its tight quarters in there.

If you *don't* know the trick (which is actually in the service manual - somehow people never seem to read that thing!), then you're looking at about an 8 hour slog.

 

[Rokovak]

48 cylinder motorcycle. You definitely don't want to lay this thing down.

Or how about a twin Hayabusa-engined, 1000hp all-wheel-drive Ultima. Ohhhhh god yes...

 

[thedguy]

Well, the inboard brakes ended on the sedans after 87 and on the coupes/convertibles after the 1990 facelift. All of the XJ40-and-later designs are outboard rotor.

As for the slip yoke, that's exactly what you get if the nut comes off the end of the drive axle. Here's what *that* looks like.

Yeah. That slipyoke concept is not a good idea - remember, the driveshaft/halfshaft is also the upper control arm!

By the way, the three hours is only using hand tools. The trick is to get the thing in the air, disconnect the trailing arm and lower control arm (four bolts a side), then unbolt the flange from the diff and disconnect the driveshaft/upper control arm from the diff by unbolting it (four nuts). You then take out the shaft and hub carrier as a unit (because setting the preload on the carrier is a PITA). Then you can remove the calipers (four bolts per side) and pop out the rotors (rotors are held on by the shaft nuts). The reason you need the lift is because you need to get the car about 3' in the air to allow the lower control arms to droop enough that you can get the rotors out past them. You could do it with some really big jackstands, I suppose... With air tools, as in a shop, you're looking at *maybe* 90 minutes or so if you hustle. Most of that time is getting the #(*&$()#@&)#$@)(&$ calipers off because the bolts don't want to come out and its tight quarters in there.

If you *don't* know the trick (which is actually in the service manual - somehow people never seem to read that thing!), then you're looking at about an 8 hour slog.

So if you have to do all that just to get the damn calipers off, how do you figure you were able to do a pad change in 3 minutes?

 

[Spectre]

You don't have to pull the calipers to get the pads out. The calipers are at the front side of the rotors next to the pinion and load from the front. You elevate the car, slide underneath, pull the cotter pins, pull the slider pins, swap pads.

(Note: Picture is from a car I had a decade ago.)

 

[Spectre]

Bumping and adding picture:

(Note: Picture is from a car I had a decade ago.)

This is why you need a lift or at least 4' of elevation to get the rear rotors out - you must swing the lower control arm down so the rotor will clear.

 

[thedguy]

And that is a good design how? Considering it's used on performance cars I'd expect brakes/rotors to be gone through at a higher than normal rate, necessitating a slightly easier rotor swap.

Hell I know a lot of enthusiasts who make it a point to replace rotors every (or at least every OTHER) time they change pads. High end street pads can be eaten through in less than 30k miles (worse yet on a heavy-ish jag), no wonder you don't see too many enthusiasts buying jags.

There has got to be a better way to attach the axles/trailing arms so that the rotors are easily changed... then again perhaps not given that even Jag has abandoned the inboard rotor design.

 

[Spectre]

And that is a good design how? Considering it's used on performance cars I'd expect brakes/rotors to be gone through at a higher than normal rate, necessitating a slightly easier rotor swap.

Hell I know a lot of enthusiasts who make it a point to replace rotors every (or at least every OTHER) time they change pads. High end street pads can be eaten through in less than 30k miles (worse yet on a heavy-ish jag), no wonder you don't see too many enthusiasts buying jags.

There has got to be a better way to attach the axles/trailing arms so that the rotors are easily changed... then again perhaps not given that even Jag has abandoned the inboard rotor design.

The last major user of inboard rear brakes is the US military - all the HMMWV have inboard brakes. I believe the commercial H1 does as well.

The last car I can think of that used it was the DB7.

If your goal is absolute unsprung weight reduction for better handling and traction, inboard is the way to go. If you're willing to trade off ease of maintenance for considerably more unsprung weight, well....

It is a fact that the later Jags aren't quite as much the driver's car as the Series III and the XJS. Both due to suspension tuning and to the additional weight out at the rear wheels.

If your speculation that inboard rear brakes are why enthusiasts don't buy Jags, that doesn't really hold water since they haven't shipped a new Jag with inboard rear brakes in, oh, 18 years now? And that should certainly apply to the DB7... which it didn't. It also doesn't make sense as the majority of Cobra replicas built with an IRS use a Jag IRS. And are these people not enthusiasts? If not, why are they buying Cobra replicas?

The big reasons enthusiasts don't buy Jags these days are 1) the line sucks for enthusiasts now, 2) what aftermarket?, 3) bad, sometimes deserved reputation, 4) perceived price, 5) that idiot pro-gay ad campaign, 6) ignorance.

 

[WellsieTRD]

I saw this wasn't mentioned (probably because everyone knows about it)
[YOUTUBE]oPQIizRp9ck[/YOUTUBE]
[youtube]f5S1NAMnYKM[/youtube]
Smart car with a Hayabusa engine.

The first ones a repost. Havent seen the 2nd one though

 

[thedguy]

The last major user of inboard rear brakes is the US military - all the HMMWV have inboard brakes. I believe the commercial H1 does as well.

The last car I can think of that used it was the DB7.

If your goal is absolute unsprung weight reduction for better handling and traction, inboard is the way to go. If you're willing to trade off ease of maintenance for considerably more unsprung weight, well....

It is a fact that the later Jags aren't quite as much the driver's car as the Series III and the XJS. Both due to suspension tuning and to the additional weight out at the rear wheels.

If your speculation that inboard rear brakes are why enthusiasts don't buy Jags, that doesn't really hold water since they haven't shipped a new Jag with inboard rear brakes in, oh, 18 years now? And that should certainly apply to the DB7... which it didn't. It also doesn't make sense as the majority of Cobra replicas built with an IRS use a Jag IRS. And are these people not enthusiasts? If not, why are they buying Cobra replicas?

The big reasons enthusiasts don't buy Jags these days are 1) the line sucks for enthusiasts now, 2) what aftermarket?, 3) bad, sometimes deserved reputation, 4) perceived price, 5) that idiot pro-gay ad campaign, 6) ignorance.

Considering the number I've seen with PERFECT paint, no tire wear and about 4k miles or less on the odometer, and the owner talking about who he paid to build it... I don't think they care, and I've never felt people who toss a blank check at a shop for a performance car much of a real enthusiast.

 

[Leonidae]

I'm actually surprised that no-one has built a dragster or something equally stupid with Napier Sabre. After all, the latest versions of that monster developed 5500hp with 130 octane..

 

[Censport]

48 cylinder motorcycle. You definitely don't want to lay this thing down.

I remember that thing. They're all little two-stroke engines, too. That's a lot of start-up smoke and ring-ding-ding!