Hi all. I've got a type4 2lt, 6rib box and standard wheels n tyres. I often cruise @ a good 65mph+ more 70 than lower. I've not got a rev counter and was wondering what revs this would be. This speed is driven by the package seemingly being in its sweet spot. I have tried searching but can't find any "table" etc that gives this information. If I knew what revs = 10mph in 4th gear I'd have an easy guide. Once I've established that my next q would be............................ Cheers Rob Sent from my iPad using Tapatalk
Hi, Maybe this could help: http://johnmaherracing.com/calculators/gear-ratio-calculator/ You'll need to dig out the correct ratios and wheel size though. Alternatively @Baysearcher has recently sent me a few documents with the information you're looking for. PM me your email and I'll share that with you. If you just want a reference point, he also told me 3700rpm at 70mph. Stock wheels and stock 6 rib.
Now there's a thing, I had RR tuning and 3700 was about where it was sweetest. I'll dig out the photos. So am I right in thinking that that's why 65 nearing 70 is the natural "happy engine" cruise speed. I'm talking thee point where you can just hover on the throttle to maintain speed?
Right that's it, we're so over I'm leaving Funnily enough as some know I'm deaf and the other day the missus got in the bus and gave it "wtf is that bloody ticking? Oh great that's going to be brilliant when I'm trying to sleep" Personally I can't see/hear what the problem is
They are so incredibly and famously loud (for a clock) that many disconnect them, at least when camping. You know you'd rather have a rev counter and they're available to match your instruments.
Rev counter is a good thing to have. My mgb has one and when driving I keep an eye on the revs and never do more than 3500 as I want the engine to last.
After the trauma of getting my clock it's going nowhere. I think if I had a Rev counter it would dominate my attention and destroy my experience. That's why I asked reference speed. If 70 is circa 3500rpm and 3500rpm is considered a safe ish prolonged cruising rpm then happy days. I can hear the engine, it might be screaming Sent from my iPhone using Tapatalk
I do 70mph at 3200rpm, (Info from an old post) Tyres are 185 65 R15 which have a diameter of 621mm Type 1, 2110cc engine, 3 rib gear box with same final drive as 6 rib: 4.57 ring & pinion (apparently it's only the final drive that alters the overall gearing). These figures could be approx 5% out because of non standard tyres Original bay window van tyres were either 185 R14 C 6PR, or 185 SR14 Reinforced (stengthend passenger car). Diameter was approx 652MM. (based on 185 80 14, rather than 82% profile) 3500rpm sounds fine for prolonged driving, but I don't really have a clue about techincal stuff. A wise man said temperature is best indication of engine
Gearbox nonsense for geeks: Trikky 2 over on prototype posted this useful information about codes and ratios Here is a summary of the different gearboxes out there but, as I said, its really only the final drive that changes the overall gearing. 1.6 liter and 1.7 liter 1st 3.80 2nd 2.06 3rd 1.26 4th 0.89 final drive 5.375 Overall in top 4.407 1.8 liter 1st 3.78 2nd 2.06 3rd 1.26 4th 0.89 Final drive 4.86 2 liter 1st 3.78 2nd 2.06 3rd 1.26 Top 0.88 final drive 4.57 Overall in top 4.02 Final drive ratios for all gearboxes; 95%of 1-4th gearsets are the same just the dif that changes much 1600 engine CA - 5.375 68-71 CB - 5.857 68-71 CC - 5.375 68-71 CD - 5.857 68-71 CE - 5.428 72-75 CF - 5.857 72-75 CG - 5.375 72-75 CH - 5.857 72-75 1700 engine CK - 5.375 72-73 CL - 5.375 72-73 1800 engine CM - 4.857 74-75 CN - 4.857 74-75 2000 engine CP - 4.571 76-79 CT - 4.571 76-79 1600 engine CU - 5.428 76-79 CV - 5.428 76-79 CW - 5.857 76-79 CX - 5.857 76-79 Code Engine 1st 2nd 3rd 4th Rev. Final Years CA 1600 3.80 2.06 1.26 0.82 3.61 5.375 68-71 CB 1600 3.80 2.06 1.26 0.82 3.61 5.857 68-71 CC 1600 3.80 2.06 1.26 0.82 3.61 5.375 68-71 CD 1600 3.80 2.06 1.26 0.82 3.61 5.857 68-71 CE 1600 3.80 2.06 1.26 0.82 3.80 5.428 72-75 CF 1600 3.80 2.06 1.26 0.82 3.80 5.857 72-75 CG 1600 3.80 2.06 1.26 0.82 3.80 5.375 72-75 CH 1600 3.80 2.06 1.26 0.82 3.80 5.857 72-75 CK 1700 3.80 2.06 1.26 0.82 3.80 5.375 72-73 CL 1700 3.80 2.06 1.26 0.82 3.80 5.375 72-75 CM 1800 3.80 2.06 1.26 0.89 3.80 4.857 74-75 CN 1800 3.80 2.06 1.26 0.89 3.80 4.857 72-75 CP 2000 3.78 2.06 1.26 0.88 3.28 4.571 76-79 CT 2000 3.78 2.06 1.26 0.88 3.28 4.571 76-79 CU 1600 3.78 2.06 1.26 0.82 3.28 5.428 76-79 CV 1600 3.78 2.06 1.26 0.82 3.28 5.428 76-79 CW 1600 3.78 2.06 1.26 0.82 3.28 5.857 76-79 CX 1600 3.78 2.06 1.26 0.82 3.28 5.857 76-79
I think for many, having a rev counter for 20 minutes would satisfy. Pretty sure mine's above 3500 at satnav 70 (73 on speedo), more like 3700-3800. How hot your engine will get if you drive at 70 for prolonged periods depends on many things - vehicle loaded weight, poptop type, roof racks and tat, how hilly, wind direction as well as the state of the engine and cooling system. So, either monitor the engine, or stick to 60-65 would be by view. CHT shows the current head temp which flucuates quite a lot. CHT will leave clueless of a gradually rising oil and core component temp though, so not enough on it's own.
I'm really reluctant to have a bank of gauges as I feel I'd be so focused on them it'll destroy the point of having it. I've seen posts where folk are pulling over every half hour because their temp looks high yet they can't even guarantee they've got a matched sensor/gauge. You've got a fair point about 20 min Rev counter as then I could quickly test my set up rather than trying to work it out. I like to play on the banter bus but really I'm quite sympathetic towards engineering hence why I'm trying to astatine the "float cruise" parameters, that point where you just rest on the throttle to maintain momentum excluding hills, wind, excess load. Mine is 70 but if that's a ridiculous rpm then I need to thank my lucky stars I've got away with it and back off. I'm talking Luton to Paignton distances too.
Rev limiters for your engine go off at 5400. You should be able to hit 60mph in 3rd, so 70 in 4th is no great shakes as far as rpm goes. Technically, 100mph is possible within the rev limit.
I have all the gauges though rarely look at them. They line up with the spokes on the steering wheel, so I have to shift to see them, but I find them reassuring as I belt up a long hill at 70.
I’ve just plugged the numbers for my 6 rib box and 195/70x15 tyres into John Mayer spreadsheet; 3,700 revs is 70.5mph. 100mph is just over 5200 revs but of course that’s just theoretical. By the way what happened to John Mayer? He seems to have disappeared half way through a 2110 engine build. I know he got involved in photography but from everything air-cooled to nothing seems odd.
