While I await delivery of my eBay cheapy cht, I thought I should research what sort of temp is considered healthy for a type 4 head? @zedders I believe you have cht gauges on a type 4... what sort of temps are you getting?
On my break in test ..my 'bbq special' head sensors got no1 st 266 and no 3 at 293°F.. Wii be able to compare to spark type plug sensors soon.. Sent from my SM-T580 using Tapatalk
I got the twin aircraft engine type from a microlite shop .. with ring thermocouple... not tried that yet.. bbq probes in the FI head temp probe holes Sent from my SM-G930F using Tapatalk
I have sensors bolted into the FI sensor holes in my new EMPI heads. Basically short sections of brake pipe with thermocouples epoxied in and bolted in with M10x1 brake union fittings that fit the thread tapped in the head. These are cast bosses between the plug and the exhaust port on no1 and no4 cylinders. Last night, I saw up to 300F heat soaking when stopped. Usually and between 210 and 300F running Or 100-150C as it reads in Celsius.
125°C to 175°C which is 250°F to 350°F Spark plug thermocouple. Dual one here from a 2CV place. VW Jim I see sells for £175, maybe he's extended the wires for that price, I paid about £110 not that long ago and extended the wires with cheapy 5A lamp cord.
Yes, 1700 beetle. It probably was on the idles for most the way. I will see if I can find some clear road in the morning to exercise the mains..
Well, I have learnt 2 things this morning... 1. Upright fan on a type 4 works very well.. 2. My decision to not bother making up a thermostat rod was daft.. On à slightly chilly morning, after running very much on the upper limits of the rev range, cht only got to 89c. Looks like I shall be having the fan housing off and finishing the job properly then.
Maybe. I think the idles are more or less there, as they take a while to shift the cold start popping, any more would be a pita I think. I will have a rummage through my jet collection and see if I have a size smaller mains.
Tell us what you have fitted. Go on, go on. I'm going with John at aircooled.net, he often says most peoples engines are out of tune too rich with consequentially too much timing, but they never realise because "it goes fine". One trick engines play, particularly noisy air cooled ones, is that they are quieter jetted too rich.
Annoyingly, I can't remember what mains are in at the minute.. I think 130.. 55 idles 30 chokes Can't remember the rest. I might whip em out dinnertime and look.
DRLA36s? I find the 4x vent or 4.2x vent thing is way too lean for a type-4. 30 vent in a 40mm carb I can't get under 135 and that should be suckier than 30 vent in a 36mm carb. You don't really need the 30 vents I'd guess, the stock carbs are 26mm vents in 34mm carbs and mine went like a rocket. I've got some DRLA36 29mm vents (turned from 28's) for sale if you think 28 too wimpy. Suit you sir!
Interesting. It turns out I have the following. Drla 36 30 chokes 55 122 180 9164.2 It goes “quite” well like that, although feels stronger at the top end than the bottom. I do have some 28 vents to try. . I should also look at the dissy, as like everything else, it was one I dug out a pile of old bits. Bosch vac jobby with leccy module.
Ha! Damn you for being 4x vent + 1 size - text book! My 1700 with it's stock 3 rib box and refurbished stock carbs took off around 40mph in 3rd up to 60mph. In a bus it was a bit poor at lower revs but at whatever revs that was it was like turning on a switch. Sounded like a Porsche. You know I like these engines, it must be dandy in a Beetle.
It is quite dandy, but you know what it’s like, you always feel like there is more to tweak out... I would mainly like a bit more torque to be honest, so maybe 28’s with appropriate mains, although it’s a temporary engine, and it goes pretty well, so I should probably just leave it alone and fit a thermostat
