BiTurbo228

Yeah I still need to go through and caveat everything where I can find out there's odd designs that skew the data. Things like runner taper and funky intake gubbins or VVT could well change the design parameters. I'm on light duties at the moment as I've f'd my back so it's not like I have anything better to do... I need to trawl through for some earlier Japanese 4v engines. I can't quite work out if big ports is just a Japanese design philosophy of the time, or if it's influenced by the Japanese cars being generally later than the European 4v engines (more 90s than 80s), and thus making more use of funky intake trickery. It certainly seems like comparatively small ports and valves is an Italian design philosophy in the late 80s/early 90s (excluding Alfa), so it could well be a cultural thing. If it does effectively fully close off one of the ports then yep, it's 1.8mm2/cc which is about the same as the S14 right at the bottom of the graph. Ah, I did wonder if the ports were more of a manufacturing ease thing. You get the same with the Saab 16v B engines, which all have the same valves and practically all have the same ports, regardless of displacement or aspiration. They'd still be pretty huge for a 3.0l engine as well (4.3mm2/cc), so right up with your 20v Volvo whiteblocks. Could also be that eyeballing a CAD model of a picture of a headgasket isn't the most accurate way to measure the area of a port... I expect the excuses stage will still require a fair dose of speculation Edit: Corrected an error with the RB20 which is now right at the tip top end of the port graph (3.9mm2/cc). Added in a few more older Japanese 4v engines to try and get a bit more representative. SR20DE, FJ20E and FJ20ET are 2.6mm2/cc which is middling, FJ24/RB25 NA/CA16DE have huge ports as well (3.0, 3.6 and 4.0 respectively). The only Japanese 4v engine in the bottom third of the graph (so far) is the little CG13 from a K11 Micra at 2.0mm2/cc, and that seems to be limited by a dinky 71mm bore.

Thought some graphs I've produced for the Maserati folks might help speed your recovery... I've been looking into benchmarking port and valve sizes for as many engines as I can, just trying to get a steer on what's what. As I don't have a storage container filled with various engine heads, I've been looking at the FIA Historic Database which has homologation docs for tons of cars up to the early 90s (and a few a bit later). That has specs on the valve diameters and port dimensions at the cylinder head face (would have preferred throat diameter, but they don't give that...the prudes). Long story short I've made some graphs plotting valve and port area against cylinder volume for as many engines as I can get my hands on. Makes for some interesting reading for saddoes like me. These are all multi-valve engines. I haven't got the 2GR and 4GR on the graphs, but I have worked out where they'd plot on them. For valve area (orange chart), the 2GR is 3.9mm2/cc which is pretty high up. Just a smidge above the YBB Cosworth. Interestingly, while your 4GR has smaller valves overall, they're similarly proportioned in relation to cylinder volume as its bigger brother (also 3.9, but a little further down so just slotting in above the Audi 20vT Sport Quattro). Probably bodes well for getting decent power and revs out of the 4GR as it's unlikely to be significantly undervalved. Port area (green chart) is a tricky one, and shows one of the limitations of using port area at the cylinderhead face. The super-heavy taper on the 4GR throws things off considerably. If the area is about the same as a 52mm circle as you mentioned, that would put it at 5.1mm2/cc which is off the top of the chart. Way in excess of the excessively large ports of the ST165 (which I note they progressively made smaller with the ST185 and ST205 GT-Fours). If it could comfortably lose about half that area while still being proportional to the throat area (as you guessed), that would put it closer to the mid-pack just next to the 323 GT-R. Tricky to tell what's better in this case as well as there's some high performing NAs with comparatively big ports (4A-GE, B16, B18), some with middling ports (S50, TU5, Mi16), and also a cluster with comparatively small ports (S14, 190E Cosworth, BDA). Edit: Mistyped on the RB20 and only counted one port out of its two. That should now be way at the top of the port graph at 3.9mm2/cc, above the B16A1

Going way back to page 1 (where I'm catching up), it's interesting about the 3mm vs 6mm steel for the engine mounts. I've had that mentioned to me before, but I measured the engine mount brackets on my Jaguar AJ6 and they're 3mm thick. The mounts are quite tucked in so you don't get so much of a lever arm on them trying to twist them apart, and they're quite well triangulated, but to be clear this is a 325kg engine and gearbox package so you'd expect the forces to be really quite large on these.

You may well be on the cards for world's fastest TR7 at that rate!

Could not agree more, in the best possible way. I've always thought a good set of staggered rear wheels does wonders for the look of a TR7, but you're taking it to extremes!

Ah, you must mean the Habsburgs. You know, the royals who managed to successfully convince practically every single royal family within Europe to marry them despite becoming progressively and horrendously inbred. See, marketing!

If the Germans had won the war, Alec 'bachelor his entire life with no romantic attachments that lived with his mother until she died at 86' Issigonis may not have had the employment opportunities he would otherwise have enjoyed. Of course, Britain was hardly a utopia in that regard either, considering what we did to Mr Turing... Ah, you must be talking about Martin Luther and the invention of Protestantism (in Wittenberg, Germany), dividing Europe along violently partisan religious lines for the next 500 years. Yet more evidence of German marketing prowess (convincing millions of Catholics that the Pope isn't actually the head of the church sounds like it should be an impossible feat...). Who else could you possibly be talking about?

If there's anything the Germans have excelled themselves at it's marketing. Case 1: 'German engineering excellence' (have you tried do anything at all maintenance-related on an Audi, or the litany of bearing failures on S54s and S65s, or their love of single-row timing chains, or Mercedes' biodegradeable wiring insulation, or 'lifetime gearbox oil changes', or...) Case 2: '50/50 weight distribution is the ideal' (it's not, anything approaching 40/60 is better for a RWD performance car) Case 3: 'Inline 6s are the perfect engine configuration' (I like a good I6, I own 3, but they're heavily compromised. They're overly long, which limits packageable bore size, which means many use overlong strokes to gain displacement and limits potential valve diameter. Their long noodly cranks are susceptible to harmonic resonance like no other engine configuration, which is made worse by any effort to improve upon bore spacing or stroke. The fact they need comparatively small bores and long strokes to get a given displacement packaged properly means they have to either be very tall, or compromise on terrible rod/stroke ratios. All of this adds together to an engine configuration that is comparatively difficult/expensive to gain power by added displacement or additional revs as one severely limits the other...beyond a certain point of course). Yours sincerely A fan of British cars that were largely outcompeted by German ones...not bitter or biased at all...honest guv.

Yeah I remember watching a video a while back about someone who had made an unequal length manifold for an S2000 to get it to sound exactly like a Subaru boxer. IIRC the Alfa Busso is of the 'short not-quite-equal primaries, long but unequal length secondaries (can't remember if they're unequal but divisible, or fully unequal). They're of the 'warbly' variety. My 156 was a 24v though, which aren't as warbly as the 12v versions. Given enough time to fish the car out of the weeds I might be able to get some measurements. Interesting you mention the KL sounding like a 4-cylinder as that's what I thought about that 2GR in the MR2, though I did get the hint of a V6 warble right at the top of the rev range in one of the clips. Definitely in for the continuous development on this thing.

Sounds like the 2GR is more in the 'seamless howl' vein like the Alfa DTM and Cosworth than the 'V6 warble' of, say, a Busso or a VQ. Though as you say, it's mostly in the manifolding, and a bit in the rest of the exhaust.

I think you mean tuning the handling Porsche style...

Garage looks good. I feel you about grit and crap getting everywhere. My old place was horrendous for that (only one real garage space, horribly cluttered so impossible to clean). Doing anything that required cleanliness like engine or diff builds was a nightmare. In my current garage build I'll end up with a clean garage and a dirty garage I can keep (mostly) separate which I'm very much looking forward to! To-do list doesn't look too bad car-wise (though I didn't spot anything about wiring on it, is that all done?). 'Finish building garage' feels like one of those single list points that expand into a whole second list with lots of bits and pieces in it. I suppose it depends on how 'finished' you need to get it before it's functional enough to 'finish' the Carina. Technically I suppose you don't even need doors or interior cladding. Just a roof, walls and floor. 11,000rpm Cosworth KF 2.5l V6 on bodies as some motivation

For the sake of your sanity, as someone who has grubbed a load of this stuff of the underside of a Spitfire for paint, don't touch the underseal if you don't have to. If this place is a known stickler, give it a try somewhere else first. Or at least go and have a conversation with someone else first. If you've got some pictures of what the other side of the metal looks like I'm sure that would go down well during that conversation. Though I didn't know about the dry ice thing at the time. That sounds like it would make it much easier.

Yeah I wouldn't rev a 4.0l that high! Not without significant work. The cast AJ6 cranks start getting nasty torsional resonance around 5850rpm. Later AJ16s with the forged crank can make it to 5950, though my understanding is they start having the same issues a bit beyond that. 102mm stroke will do that. Though that racecar video doesn't look particularly wanting for revs. Wonder what it's actually reaching, and what they've done to the engine. The 3.6s 92mm crank is much more reasonable though. Roughly comparable to the S38B38's 90mm crank, except it's much stiffer. Ginormous main bearings will do that (76mm!). Ford and Mopar big blocks are bigger, as is that monster 472 Cadillac V8. Cummins 4BTs are as well. Apart from that, I haven't really come across anything as beefy. I've seen racing 3.6l AJ6s that reliably rev to 8000rpm with Pinto forged pistons. They're monster engines, just in incredibly mild standard tune. *Like-for-like forged cranks are actually worse for torsional resonance as they're not quite as stiff, though they can tolerate resonance better. AJ16 has lighter conrods and pistons though, which might help.

Ah, probably not that then! Not sure you'd need an O2 sensor to be confident about pushing the timing forward a bit. Plenty of engines running with slightly advanced timing to no major harm. O2 sensor would let you dial that in though. If you want to get ambitious, I have it under good authority that 3.6l AJ6s are a set of ARP rod bolts (and presumably the appropriate regrind on the cams) away from 6500rpm

Well you've certainly done that a lot quicker than I've done mine! It's taken me 8 months to do all the ground work and I'm just getting to the point of laying some concrete down. 2-bay plus a workshop area? So maybe 6x9m or something like that? Should be a nice functional working space that!

Hum. Crank sensors on Alfa 156s like to die in a similar way to what that sounds like. Start off by working ok when cold, but losing the top end once the engine's warmed up a bit. Then the range of revs they work at progressively shrinks until they just stop working altogether. I know crank angle sensors are one of the first things to check under 'won't start' conditions on AJ6s. No idea how much they are these days, but might be a reasonable thing to swap around anyway.

Please delete if this is the wrong place to comment, but I can't see a discussion thread for this. Such an awesome car. Love a TR7, and this is nuts!

Is that a dinky little turbo I see...

To be fair, bog can't rust the metal underneath it if the metal underneath is actually plywood

It'd be interesting to see the crank on that. I wonder if they've done anything funky with tungsten counterweights or if it's just a bog-standard style crank.

Yeah I've stopped using POR15. Doesn't stick to fresh metal, needs to be absolutely utterly spotlessly clean, whole can goes off before you end up using it all. It's great stuff if you can get it to work, but it's finicky. I use Bilt Hamber epoxy now and it's much nicer to work with.

Sure you know this already but door handles are silly expensive as they were used on 308s, so either stash them if you break yours or sell them and make a profit before you've even touched anything else (same goes for the other rotten car you left behind). If it's an early car and yours is a later one then it'll have a fibreglass roof and yours will be ally (maybe just the Bertone-built ones). Saves 2kg right up top (9.6kg vs 10.6kg). Do you know if it's the earlier 1300 Uno Turbo engine or the later 1400? 1300s had closed-deck blocks so are a little stiffer and take boost better, but both will make silly power for an X1/9 with the right turbo. Man I want mine back on the road...

Nice find! Lots of goodies on that. I've got Uno Turbo front brakes on mine. Work well, but end up pushing the bias even more forwards. I fitted Fiat 132 rear calipers (same caliper, bigger pistons) which has sorted the bias out a treat, but I've ended up with a bit of a mushy pedal. Works, but doesn't feel as nice as it did. After I sort the engine I've got a bias setup on the mind. Would be interesting to see the engine bay. I like the relocated coolant tank as it's all a bit snug in mine for air filter placement (apologies, only pic I have of my engine bay has my chops in it...):

That's my understanding. Flat 6s are essentially just flattened I6s, so there's no fundamental reason they'd sound different. 2v vs 4v has a difference in sound as the valve opening and closing events are more sudden in a 2v giving them a bit more 'bark'. Silencer design could well make a fair bit of difference. I get the impression the packing in silencers cancels higher-end frequencies better, so it could end up sounding a little raspier with a different design. You could just put a tin can on a string with some pebbles in it to give it that 911 'clattery' sound at idle and/or replace the end of the j-pipes with butterfly valves for an open exhaust system as and when you please...