If you had only used scotchbrite, it'd usually be a no brainer (but it might not have gotten the rust off). But with 'real' abrasives, it's less the case. I'll also note that in the second (cleaned up) pic - it looks like there's a score/groove across each of the two lobes toward the bottom of the pic. I can't say for sure as it might just be the lighting/digital pics making it look like something but in reality it isn't a groove, just a colouration or something (I remember trying to take pics of cams for another forum and it was just about impossible to show what was easy to see with the cam right in front of you).... So i'd be a bit reluctant. Then again, if it owes you nothing, you could always try it.

I would _definitely_ add my name to the list of people (on any forum) who recommend Clive Cams. I couldn't tell you just how good their reputation is, and they earned it fair and square. A few years (actually probably closer to 10-12) ago there was a big issue with lifters from the US that had been ground flat instead of the usual very slight convex shape on the foot. They were lunching cams left right and centre. Some other places didn't check em, and customers cam's were destroyed within a few hours of running. And some of these other cam places wouldn't do anything honourable with regard to replacement. Clive Cams checked their stuff, and their customers (afaik) didn't suffer the same fate. I think at one stage Clive was even contacted about a big job from one of the manufacturers, looking at getting all the remaining lifters that were 'wrong' and machining the proper shape onto them so as they didn't all have to simply be binned. I don't know if they went ahead with that or not.

Anyhoo, when other companies were shafting customers, CLive Cams did rigght by theirs, and ironically (or not) were actually a lot less expensive than the purchase price for cams from some of the other mobs to start with!

I've sort of paraphrased the above to try and condense it, but anyone who happened to be on the moparmarket forums circa 2002 (approximately) would know just how big of a thing this lifter problem was, and just how bad one cam firm (in particular) was in terms of their customer service, production values, quality control and general integrity.

Short version, either try it, or take it to Clive Cams and get their input on it, and if need be, look to them for a regrind if you want to go to a different cam spec and this cam can't be used as is.

I've got 2 coupe shells I have to strip. You are absolutely welcome to grab a big section out of either to be able to plate yours with absolutely free.

I did a post on this a few years ago - I dunno if it is still easy to find.

In very basic terms, THE single most important dimension of extractors is primary pipe diameter.

Since the dawn of working on engines for more power, a bunch of guys smarter than me discovered that the headers/extractors work most optimally when the gases inside them are flowing at an average speed of X (I forget what it actually is, and the actual figure isn't as important as knowing that such a phenomenon exists). So then they worked out that if each cylinder was a certain capacity, then at a certain rpm, it'd take a specific pipe diameter to attain that average speed.

In practice, yes every engine is different, rod length, port efficiency, etc etc etc, so you'd actually find, if you could test it, that a particular 0.25mm difference in pipe diameter would be a little better for some engines, and worse for others.

THe thing is, short of a million dollar budget, you really only get pipes made (that you can then make extractors from) in 1/16th of an inch increments or 1/8th or whatever. As an example, most street hemi 6 cylinder engines could actually work pretty well with 1 11/16th primaries. But the tooling to bend pipes in this diameter doesn't exist (or isn't common) so the two main sizes are 1 5/8" or 1 3/4". Since the hemis have a (relatively) short rod for their stroke, the 1 3/4" is the go for anything going above about 280-290bhp (actual hp, not claimed).

But anyway back to the a series. Oh, and a big point to make here - just because the math pinpoints "X" rpm, well that's the theoretical 'sweet spot' where the pipes will give their biggest boost to torque, but the pipes will tend to work VERY well as much as 2000rpm either side of that. Certainly they'll work over 3000rpm (1500rpm either side of said sweet spot).

Note that this isn't where the motor would make peak torque, it's just where the extractors are giving the biggest boost to torque. IF you have a cam/port combo that makes peak torque a lot lower or higher, it will still tend to be the main factor as to the torque curve (unless you run an exhaust so restrictive that it is choked to death by mid range rpms or something) the extractors won't magically shift this powerband a few thousand rpms either direction, they'll only be working at _their_ best at those particular rpms.

You have to allow for the pipe thickness, as it is the inner diameter that counts for the math, but the pipes are measured by outer diameter. I generally round it off to 1/8" less than the outer diameter which isn't perfect but it'll do.

With an a-15, std bore, the main primary pipe sizes going around tend to be 38mm and 35mm which are basically 1 1/2" and 1 3/8" . the smaller of the two has its sweet spot (for a std bore a15) around 4700rpm (and looking at this I might have mistakenly plugged in the numbers for 1 3/8" pipes in a post I made about 88mm stroked a15 buildup stuff, hte perils of posting without ever getting much sleep!) - which means it'd work from about 2700rpm to 6700rpm - not a bad street/mild/stock range. For 1 1/2" primaries you would be looking at 5770rpm or from 3700-7700rpm (or maybe 4200-7200rpm) that'd be very decent for a mild-more serious streeter.

---------


Primary length does have SOME effect but it's far lesser than that of diameter. Basically longer will make them work a little better at lower rpm and shorter will be better at higher rpm. There's (again) somewhat well established and tested lengths to coincide with the sort of rpm range you are chasing. FOr a streeter possibly as long as 34-38 inches would be good, but don't lose sleep if it's shorter than that, the effect is icing ont he cake, not 'end of the world' stuff. Equal length is 'nice' but the thing is, they might all be 'equally wrong'! So again, a few inches difference from one primary pipe length to another - just don't lose too much sleep over it.

FOr an all out racer, sure, but for anything else where you don't spent a few grand just chasing 1-2% power increases, just don't worry too much.

Collector size. There is certainly such a thing as too big. BUt there's also 'adequate' and 'on the restrictive side' . Generally you'll find most come with 2inch main collectors. Not a bad place to look for an a15, esp a street one. You could start to make a case for 2 1/4" at really high power levels but again, unlikely on any streeter. A different engine, I'll grant you, but 2 inch collectors work on race mini engines up to around 140-145bhp, so it's a good enough size for that.

Where it can all fall down is the muffler itself. THe problem is the right sized pipes and collector will not work well at all with a restrictive muffler. you have to make a call on just how quiet you need it because generally good flow and low noise aren't easy to combine.

There is a way you can 'trick' the exhaust gases into thinking they are exiting from the collector into open air (which when done right - i.e. the collector into actual open air = the best exhaust scavenging effect at the most power). and that is a pressure wave termination box. All it is is a big pipe/section that the collector feeds into, where the cross section area increases dramatically. It needs decent cross section area and volume (about double the total engine capacity at a minimum afaik and there's almost no such thing as too big) and then it'll work like an open exhaust. At the other end of this big 'bucket' or cannister, you simply funnel it back down to go into the rest of the regularly sized exhaust pipe and on to the rear muffler. Done right this lets you get the exhaust scavenging effects and still run a muffler that quietens it down enough to keep you safe from unwanted attention (be it the epa, the boys in blue, whatever) and make it liveable for daily driving.

As far as mufflers go, there's massive difference in flow and noise elimination from brand to brand, and I honestly don't have ANY decent advice on what brand is currently a good option (I'd also add that you can find similarly named brands that are possibly low buck copies from who knows where being sold as the real thing, so it is a battle to get the best outcome)

Another option you can look at is brazing a copper pipe into the main exhaust just in front of the muffler, and routing that (with enough loops so that the temperature doesn't potentially reach the cockpit/guage/whatever ) to a pressure guage. You are going to have to accept some backpressure (though for optimal power zero is the go) to get the noise down. If it is around 2-3psi, that's a very good place to aim. If it is 5psi or so, it's certainly still a reasonable enough compromise. Above 5psi, esp over 10psi, and it's costing you power serious power.

I'll do a diagram of a pressure wave terminator box if you wish, it can be easily enough made with a welder, a hammer or two and some time. In theory some 'resonators' do the same job, but most of them don't do it anywhere near as well if for no other reason than they just don't have the size/volume to achieve it. Depending on the precise shape you aim for (it doesn't have to be perfectly round, you could oval it for better floorpan/ground clearance) it may or may not require a bit of floorpan massaging to clear it without it being too low to go over speed bumps and the like.

The following is opion/based on experience (but I haven't worked on a million a series dattos specifically). It's not the last word, I'm not perfect. I've tried to provide reasoning explaining anything I've said, but read it all with a critical eye, because ultimately whatever you do with or to the engine your the one who will be responsible for how it turns out.

If it 'must' stay NA, and is deliberately going to be made to work at more all round user friendly rpm range then the long stroke crank is worth a look. It'll likely cost you more than running a diy sc14 supercharger on a std stroke a15, and produce less torque and less hp, than the supercharged option, and also not last as lnog as the 'budget/ghetto supercharged a15) but that's just the way it goes.

It's also worth noting that if you do go to a supercharger, you'll need to run a lower compression ratio than you would with an NA 1.7 and a different cam (less overlap, less duration, and specifically for supercharging, you'd run a little more exhaust duration than you would for any given intake duration for an NA engine. You'd also not be needing or using twin webers (or if running efi, a single throttle body in front of the supercharger and an injector in each manifold runner instead of itbs). You'd not need the longer stroke, the supercharger will pump in all the air you need, so the capacity of the engine is a little less crucial. So aside from knowing a fairly mild a15 with supercharger will make more power than the stroked NA 1.7 ish sized motor, there's also the issue that not a lot of the bits could be retained, so if you found yourself still wanting more grunt, then it'd be easier and way cheaper to just pursue forced induction from the beginning

Now for 'real' racing you will get to the point as far as engine capacity goes, that it's just so big (like around what 1.7 litres if you went with a 2mm oversize bore and 88mm stroke) that no matter how well ported the head is, the head is just not capable of properly feeding all that capacity at higher rpm, and the increased friction from the longer stroke would combine with that and cancel out most if not all of the gains of the extra capacity.

But you aren't looking at those rpm levels so a properly "pocket ported" head will do the trick and be capable of supplying enough flow to feed that much capacity. Pocket porting is basically focusing the work on the bowl area (around the valve/valve seat and valve guide boss area of the intake and exhausts) these areas are essentially a 'bottleneck' and flow a lot less than the main 'straight' section of the port. So you effectively work on those areas to minimise as much as possible the obstructions. you won't be opening up that straight main section of the port and as a result of there being no increase in the cross section area of that part of the port (and those more restrictive regions won't exceed that size/area/flow of the main part pretty much no matter how much time you spend porting them) so since that area isn't increased, the flow velocity won't be compromised, meaning no loss of low/mid range output and efficiency.

On a similar note the added friction from the longer stroke is far less of a factor/penalty at lower rpm ranges. Same story goes for rod:stroke ratio. Shorter rods mean more rod angularity and so more 'side thrust' and more friction, power losses and stress/wear and tear on the bore walls and the piston thrust face on the skirt region. In your case presumably you wouldn't run shorter rods, but a longer stroke with the same length rods so it's 'like' running relatively shorter rods. Again, at more reasonable rpm levels it's just not any real worry.

Lighter flywheels mean quicker throttle response, and with low enough diff gears (like 4.875:1) well the difference in acceleration in first gear can be noticeable. The gearing (first gear combined with said diff ratio) is just so low that a heavier flywheel will actually manage to slightly reduce how quickly the engine can spin to redline. By second gear the effect is reduced a lot, and by 3rd and 4th and 5th, it's negligible. For a purpose built hillclimber, the lighter flywheel is definitely the go.

Now presuambly the engine combo/rpm range/usage would actually rule out using 4.875 diff ratio, probably 4.1:1, maybe 4.375 (but the latter is imo highly debatable with the longer stroke) but certainly not 4.875. WIth this in mind, much like how the effects of a super light flywheel is reduced progressively to nil as you go up through teh gears, well with 4.1s the advantages will be minimal. GIven the longer stroke (if you go ahead with it) and the desire for long engine life, you really can't aim for anything beyond 4.1:1 diff gears imo, and furthermore you'd definitely want to be running a 5 speed with an overdrive 5th, not a 1:1 5th (though admittedly those boxes/gearsets are darn

That said, I'm talking about more exotic ultra light flywheels here. The good old trick of using an a12 flywheel (which is slightly lighter than the a15 one) has no real 'drawbacks' and they are plentiful, so you might as well use one. The gain in throttle response won't affect in gear acceleration much, but the quicker response can help with regard to launching the car from a standstill/various shifts. The ultra light flywheels also mean the rpms drop a lot quicker so it is harder to keep the engine rpms up, and it makes them a lot less user friendly in heavt traffic (it's not unusual for tractors - that have to potter along at very low speeds, and also can get slightly bogged or whatever - it's not unusual for them to have much heavier flywheels - the inertia in the heavier flywheel will prevent the engine rpms from dying and stalling when you hit a bump or whatever. Anyway, the a12 flywheel just isn't much lighter than the a15 one, and heavier than a race spec one, it won't incur the driveability issues, so again, go for it.

knife edging a crank is only a big deal for much higher rpms in general. Additionally, generally the more weight in the crank, (when it's not ever going to see sky high rpms) the longer it will last, so I'd definitely leave it as is.

Out of curiousity, what is the plan as far as the crank itself goes - is there some company out there offering a custom (possibly billet) long stroke crank for the a-series, or are you taking an a15 and having the rod journals welded up and offset ground to attain the longer stroke?

Since the capacity is larger than an a15 (and a lot bigger than an a12) - in general you'd aim for more airflow headwise (though the rpm limitation helps avoid some of this) . Also a cam that would see a particularly grumpy idle on an a12 will be smoothed out a bit in an a15, since at any given rpm range the a15 (or stroker a17!) will need more air/fuel to feed it. So look at a cam that is something above what might be considered mild, but something short of full race. I'd suggest that perhaps something with 280 - 285 degrees seat to seat duration (and as much lift as they can safely achieve for that duration without risking lifter/valvetrain issues) Quite often the sort of cam that would see light of day in a rally engine would be a good option (but that wuold be the biggest you'd typically want to run, and certainly a slightly milder one could be justified). A pretty good rule of thumb here is if there is ANY doubt at all, go smaller on the cam duration not longer.

As a very very general rule of thumb, when you go longer and longer on the stroke, the cam lobe separation angle tends to want to be a little bit narrower. Nothing drastic here. If a particular cam (approx rally spec) had 110 degrees lobe separation (it's probably narrower to start with on an a series spec cam 110 is merely used for sake of example) then with an 88mm stroke you'd want to perhaps close it down to 108. This has to be decided upon ahead of time (obviously) and the cam has to be ground to suit. You can't (of cuorse) alter lobe separation on a single cam engine, not like you can with dohc where you can individually time BOTH cams.

This narrower lobe separation (all else being equal) will result in a slightly rougher idle. Initially that might not make sense. But what happens is that at idle, the throttle plates are closed so very little air can be sucked into the cylinders. The tighter lobe sep means more valve overlap (period where the exhaust valve isn't yet fully closed but is close to closing, and the intake valve has already started to open - so both are open at the same time) - well the exhaust pipe has no 'throttle plate' in it, so at idle, whilst the intake throttles are closed, the engine can and will suck some air (or exhaust gases, or a bit or both) back in through the exhaust port. even if it was air, it was from the exhaust, so it isn't carrying with it a well distributed fuel mixture to burn, so idle is slightly compromised. Not night and day, just trying to be up front about it. Ironically once the throttle plates ARE open (even just at cruise rpm/power levels, and certainly at full throttle) the tighter lobe separation angle (within reason, obviously you can go too far) will lead to improved mid range torque without costing much if any peak power. And that's worth far more than peak power in 99 out of 100 situations even on a circuit.

The compression ratio you can safely run depends on a lot of things, fuel octane. head material (alloy means you can run higher comp than cast iron) chamber design (closed chamber head, with some quench areas will allow the higher comp ratio, but you might not be able to get it low enough since there's much more capacity being squeezed into the same chamber size, so the increase capacity leads to more compression. If however you can get dished pistons that still have quench areas intact (i.e. the dish is a similar shape to the chambers with some flat areas surrounding them, not a full dish as such). if you can get that sort of piston dish, you can run more comp. Bore size (generally the larger the bore, teh less comp you can run but even at 78mm the datto engine is a relatively modestly sized bore, it's not till you get into bigger 4/6 cylinder regions that it becomes a big issue. The other factor is camshaft duration/intake valve closing timing. Very very generally speaking, the later the intake valve closes, the higher compression you can run. SO with the sort of cam duration (and later intake valve closing point timing) you'll be running, you can run more static compression. You shouldn't have much trouble with 10.5:1 with that sort of cam timing (approx 280-285 duration) and I'd almost make a case for a touch higher if you had access to 98 octane, but you don't so 10.5:1 should be ok. If you can't run a closed chamber head/matched piston dish shape and the resultant significant quench areas and/or you can't run it so that the piston at tdc is no more than 45thou from the flat sections of the head deck (which is a combination of block deck height, piston crown height, and head gasket thickness. Look up quench on various car sites to learn more but basically if there are large flat areas sandwiched together when the piston is at TDC, then it works as if the fuel was much higher octane, but if the piston/head don't get that close to each other at tdc it just won't work. Ideally you'd aim for a tighter gap than that, but then, with thermal expansion, the possibility of very slight piston rock at TDC and all that, you would risk them actually making contact and that would be game over. Anyway, if you couldn't get decent quench then you'd have to reduce the static comp ratio to be safe. around 10:1 would be more inline possibly even less (and if you can't run over 10.0:1 then you really start to lose out at higher rpms (bigger cams not only 'allow' more comp ratio, they more or less 'need it') - and this dropoff in power can actually mean that if you (for arguments sake) had to go down to around 9.5:1 compression, you'd actually get a better performing all round combo with a smaller cam (perhaps around 275 adv duration or thereabouts)


Exhaust wise, the 4 into 1 headers in general tend to make the most power (but a bad 4>1 will lose out to a good 4>2>1 setup). There's a set available through hurricane 4 into 1 with 38mm primaries. Primary pipe diameter is by far the most critical factor in matching engine capacity/rpm and thankfully the maths behind it has been worked out by a bunch of people literally decades ago. Anyway 38mm primaries on these headers (they also make a 4-2-1 which apparently has 35mm primaries, which would be too restrictive for even a stock cammed a15 to be honest) will find their own peak efficiency (where they boost torque the most at about 4200rpm. Obviously they aren't that 'narrow' in their range, and whilst 4220 is technically their peak rpm point, they will happily and usefully work to optimise torque across a good 2000rpm or so either side of that. They are very very marginally too narrow, but nowhere near enough to lose sleep over and are off the shelf. Ironically their primary pipe length is a touch short for an a15 (a street/mild competition rpm range one). Whilst primary pipe length doesn't have anywhere near the overall influence that diameter does, running shorter pipes will tend to bias the rpm range upward a little. SO in this case they actually are a fairly good option. they come with a 2inch collector which is about right too.

One throat/barrel (webers or itbs) per cylinder always produces the best throttle response and wider powerband, whereas a larger plenum and single throttle body tends to see peak power *(if optimally sized). For any sort of circuit/climbing work the itbs/webers are for sure the way to go

drivetrain wise - there's two issues - weight of car/engine output being the first. But there is also shockloading - in other words even with a stock engine, if it is revved up hard and the clutch is let off too quickly, that sort of shock will eventually break the diff or the gearbox. so what I am saying is that whilst the 60 series box will last ok for a street a15(and maybe a17) IF the driver treats it very considerately - no harsh launches and a slightly restrained lift off of the clutch after gearshifts - it won't die overnight. But if it is seeing hill climbs, any rallying (where the grip can get loose then grab really hard every few meters) and drag racing/drifting, you're going to see the end of the gearbox a lot sooner. I reckon it'd be a good case of where at least a 63a box (which can be found with an a series bellhousing, thuogh they are rarer) or a 71b box conversion (tehre's a thread on that conversion on this forum, but it's still in very early stages so you'd be doing it as a one off, before there'll be a how to write up (or in the much longer term possibly the option to have the bellhousings cut/welded so the 71b boxes can be bolted up.

afaik the vanette with the most interest here in aus would be the ones with the a12 engine which should have a h165 and 4.875:1 ratio

wards, with respect don't put words in my mouth, I know about the test bar stuff. About the only way I could perhaps convey to you that this is the case is by saying (and I'm sure you will have seen this, but likely anyone without experience with this sort of work hasn't) that it's not unusual on bw diffs _before_ any shortening or work has taken place, esp if they've been in a relatively heavy car, that they are no longer actually straight but can tend to have a slight bend, with the outsides being 'forward' vs the centre if that makes sense (I'll do a diagram if not)



, I know about the potential for warpage, but it also depends on the extent to which it has to be altered in order to shorten it, and there's certainly (not that that is being discussed here) some difference between shortening and doing a complete sheet metal housing, or re-inforcing a housing with bracing along the back of the diff as is done to some ford 9" housings. I also made absolutely no reference to a stick welder, so I don't think it's fair to criticise me for allegedly thinking something that I categorically did not think. Just for the record, it'd be a couple of tack welds as necessary (and re-checking before proceeding) with a mig, and then tig for the rest. Not that that is exactly a government secret. If the person didn't have use (and ability) with a tig welder, I'd 'maybe' in some cases believe it's possible to do it with a mig, maybe. But a stick welder? Not in this lifetime.

I'm not suggesting you aren't good at what you do, so please take this in context. I am aware of more than a couple of people who have done this themselves and the cars are still going strong some years down the track. They had access to decent lathes and milling machines that allowed them to make jigs and bars in order to make it straight and make sure it ended up straight afer welding. I'm also aware of more than one diff shop who do some atrocious work (and I am certainly not putting you in that boat) and continue to do business none the less.

You're not bursting my bubble. I would hope I'm not bursting yours if I was to simply say that whilst it might not be a good idea for homer simpson to try and diy this, people with fitting and turning or similar backgrounds won't exactly struggle to do it.

I hope this has come across politely enough, I'm just saying that you have mis-interpreted and partly mis-represented where I was coming from, and have made some incorrect assumptions about my knowledge on the issue. Now perhaps that's because I didn't write a 10,000 word post covering all possible questions (ironically that's why some of my posts on other forums have stretched beyond a page or two - because any time I left out the smallest detail someone would nit pick it) that might arise. Can't help that, I just don't have the time for it much these days. SO if that's made it look like my earlier post was in that context, no dramas.

I don't take offence to what you've said, and I hope I haven't caused any with my reply.

THe hilux diff is the go here for sure, not just ratios.

MY advice isn't 'new' or revolutionary - do it slowly, small section at a time and leave to cool, then weld the 'opposite' side for about the same amount. Getting the 'dowel' pieces machined on a lathe to ensure it is all 'straight' is the hard part (and it's not 'that' hard either).

Once you've done yours, serious suggestion - consider weighing up what you'd want to be paid to do one for someone else. And if you come to that $$ figure, advertise the option. You never know, it might be the start of a decent little side earner for you (or anyone else).

Just in case you thought the idea of a firm with 'issues' suing the victims of their incompetence was out there in the twilight zone:

http://www.spokentorque.com/forums/sh ... les-suit-against-EVIL95GT

http://performanceforums.com/forums/s ... e-Dyno-Still-around/page4

http://www.aussiev8.com.au/members-lo ... g-head-trouble-yanks.html

http://www.yellowbullet.com/forum/sho ... 0da40e214792e5ba&t=546566

If you have some spare time read through these threads. The guy in question has had allegations against him in 3 separate countries. Scary to say the least.

There is a website, in spanish, and apparently they only do business over teh phone, very slow to respond to email (if at all). I ended up passing on it because communication would have to go through various different people some here some in Sth America and it just seemed too problematic. But here's the site anyway:

http://www.metalurgicariera.com.ar/quienes_somos.htm

good luck and please let us know if you make progress on this front.

JOhnB - there's two links of interest on the kameari gearsets:

http://www.rhdjapan.com/kameari-super ... set-s13-s14-r31-r32-58307

and

http://www.rhdjapan.com/kameari-super ... -l-type-fj20-fj20et-58308

initially it appeared that the first link was the 'right' one based on teh idea that we were going to use the 71b boxes specifically found behind ca20 engines in series 3 aussie spec bluebirds. But on looking at all the various car/combos they match we are fairly certain that they are for the 71c box.

the second link is for a variety of 71b boxes. so we 'know' it'll fit most. To be 'extra' sure what we (D and I) have been looking at was to get the set for the L-type type A. In this case, if tyou lok down the list, it says the L type set is for 71b boxes. type A in this case is not referring to the 71a (fore-runner to the 71b of course) box, but rather the type A ratio set. Now just by chance, luck, whatever, this set has the 2.6xx first gear, and (for many of us) a better/more even spread from 1-4. not quite as close as their other option, but about as close as I'd ever want. The more even spread is especially what I like. We did (afaik D did) submit a query as to the overdrive ratio. No reply. But on thinking about it I think it's just a case of the 5th/OD ratio is going to be determined by the gears in teh box you swap their gearset (which only contains the gears necessary to achieve said ratio alterations, not a complete new gearset as such) and whatever 5th gear ratio it started with.

We could debate what 'ideal' ratios may or may not be, suffice to say that these happen to be pretty darn good, suit me like they were made to my own specs (imagine that!) but perhaps just as importantly they are light years ahead of any of the factory ratios. Don't get me wrong, if they weren't available, I'd still want to do a 71 series conversion, it's not like the factory ratios are impossible - just not 100% ideal.

That option 'should' fit the ca71b boxes but we don't know 100% for sure. What we do know is they'll fit the series 1 and 2 aussie bluebird boxes (71b boxes behind the L series 4cyl). SO at the moment the status of this conversion is we're going to source a couple of 71b boxes from bluebirds to suit, and order a gearset (I'm not sure if D wants a set as well, but at the very least I'm going to get one). Beyond that there's been a bit of a holdup in loaning a jig that someone here has made owing to their hectic work schedules etc. SO what might have to happen, is I've got another friend with new milling machine and lathe (I've got access to both but both are a little old and probably capable of some margin of error 1 thou or 2, which isn't ideal for this app) and get him to spin up a mounting jig to allow the 71b casing to be secured perfectly inline with the crank tunnel on a spare engine block. and then cut/join the bellhousing to a spare 56a bellhousing front section. No call (for the moment) has been made about clutch actuation. Personally I'd love to be able to retain a cable clutch, if only because that would mean the jig would likely see more use (I think the less that has to be changed, the more people might want to get a 71b box modded to fit their a series)

FLywheel wise, that's been covered. There's 3 clutch/pressure plate sizes available for the L series boxes most to suit the L series, but one which will fit an A series flywheel as is. The 'middle' sized one will just fit onto an a-series flywheel, but would require it to be re-drilled/dowelled to suit the further outboard pressure plate attachment points, and machined so the flat 'step' where the clutch plate contacts the flywheel matches that of the 'middle sized' L series ones.

http://datsun1200.com/uploads/photos/22568.jpg
http://datsun1200.com/uploads/photos/22569.jpg
http://datsun1200.com/uploads/photos/22570.jpg
http://datsun1200.com/uploads/photos/22571.jpg

The last 2 pics show the difference in diameter vs a std a series clutch plate (or attempt to!)

THe input shaft 'spigot' finger section has to be machined down to fit inside the crank tail of an a-series. I'm holding off on this until I get one of teh kameari gearsets just to be certain precisely what comes in their kit, I may not have to machine the factory one, but might have to machine the new one if it comes with their close ratio kit.


What else - I picked up a decent tig welder about a year ago, so that's taken care of. Only other thing needed to purchase (not mentioned so-far) is a big propane forced fan space heater or two. I want to use these to pre-heat the block/gearboxcase/bellhousing sections before welding them, and then afterward to keep em hot and cool them down as slowly as practical. We know from Simon (and obviously this makes perfect sense) than an early prototype of his cracked, but wasn't extensively pre-heated (to be fair I think it was more to evaluate if it could be done at all, not intended to be the last version) . Anyhoo, the next prototype was thoroughly pre-heated and afaik is still in the car to this day going strong and setting lap records here there and everywhere!

SO it's a work in progress, albeit moving slow as a glacier.