logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
Jul 20, 2022 20:22:41 GMT
|
Today I had an opening in my diary at the same time as my long-suffering mate Barry, and we managed to get together for some mutual spannering. The object for today was, working out what the hell is going on with frank, so we went back to basics. First thing, check to see if my timing light is dysfunctional and nope, Frank is running with stupid amounts of ignition advance. Then we tried to reset the advance, and it still wouldn't run right, next we checked the cam timing, seeing as the cam now runs the dizzy again. I had set it up on the standard acclaim timing marks but not with the extra half tooth which is standard for an acclaim, so that was reset. Still no joy, next was the vacuum advance, which I swapped back to a triomatic and when refitted started to fall into place, the dizzy was turned all the way on its stop and fully advanced, (dizzy turns CCW body was fully CW) so I advanced it one tooth which improved things, a short drive, and it's a lot better, in fact it pulls so much harder in first gear it looses traction, but there is a hesitation / stumble if you don't ease in to acceleration from idle. It't not right, but it's a major step in the right direction. I've found a new acclaim dizzy made by Ignition car parts in Basildon, they say it does away with the need for the ignition module and connects straight to the coil, which is good, but they don't list the advance curve, so I've sent them a message. I have also been thinking about Darkspeed comment about exhaust manifolds, I've found a nice looking Honda b16 4-2-1 exhaust fanimould, it looks well-made, has fairly equal length pipes and best of all its at a pocket money price, and It's not far off my route for the weekend after next's trip to London. Dan
|
|
Last Edit: Jul 20, 2022 20:59:29 GMT by logicaluk
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
Jul 24, 2022 12:39:48 GMT
|
A run to the DarkSpeed Shop Friday night with all the travel chaos down south I had a relatively easy run over to almost Wales, which went quite well despite 2 torrential rainstorms, road flooding, variable motorway speed limits that fluctuated between 40 and 50 MPH, with pretty lights that flashed when some cars drove past on the 40 ones then 50 ones in between, oh and a horse box that parked itself in the scenery. On the way I dropped off some pistons and conrods to another acclaim fanatic who's rebuilding an engine, nice to meet you If you're reading this John. Stayed the night in The Red Lion coaching house, woke up far too early, went for a walk at 6am around Ellesmere to kill some time, saw some interesting sculptures in the park Another acclaim fanatic drove 2hrs from Bristol to collect an unobtainium chrome front bumper at 8.30 in the morning. Ate a good breakfast I arrived at Darkspeed towers about 10am, and promptly lost track of time. DS set to work with a pair of dividers, measuring them with his vernier, making notes and drawing digrams on the white board and having to stop to explain things, so I could understand what he was seeing, the major restriction was the throat of the valve seat narrowing the inlet down to 30mm Then explained how to work out how much it could be opened up and how that would affect the flow at low lifts. The seat will take a 1mm larger valve allowing the seat throat to be enlarged further, DS also pointed out that the head has no squish area and there was a lip on the back side of the valve. Then on to the bench, first the bare head, which seemed to flow better than expected, then the bare head with a radius which didn't flow as expected, doing exactly the same at the bottom-end, gaining a small amount in the mid-range and flowing less at the top. But I didn't get a pic of that "Air does strange things" says DS I wanted to test the rest of the inlet tract, first we added the manifold. The carbs were fitted and tested, then the mesh screen in the tops of the carb trumpets was removed, that made a 2 CFM difference. The complete air box, which made no difference. Next up we (I say we because I helped bolt the manifold on) tested the injection manifold which gave no restriction on top of the head, we also tested the throttle body with and without the spring in the shutter, but I can't remember the results. Then we decided the civilized thing to do was stop for food, and nipped out to chippy, afterwards we returned to test the exhaust port, due to the configuration of the acclaim head and manifold we couldn't fit the exhaust manifold, but DS didn't think it would make any difference on the bench anyway. Then DS got out a die grinder and worked some magic, opening up the valve seat to 31.4mm and blending in the short side radius, which took a surprisingly short amount of time. Then he chucked the valve in the lathe and ground off the lip. That half hour of work gave nearly 10% increase in flow @ .350 lift DS showed me a simple tool that he made for cutting out the throat of the valve seat. I have a couple of tank cutters, one of which that should be easily modified to the task After sleeping on it, my initial plan it to do nothing right now. The data gained from my trip will be put to use at a later date Here are my thoughts, and theythese are only good for the length of time it takes me to post them and subject to change at any moment. If an off the shelf valve can be found that can be modified to fit for sensible money, it will be worth it, if not then ill just open it out to 32mm and blend in the rest. The cam looks to be the limiting factor, with not enough duration, as cast blanks are not available I will look into a complete 1 off cam but think that will be far too expensive Compression could go above the 9.5:1 and still run on 95 octane, but I only want to do that to the head I have on frank, the rest of the head work will be just fine with a TURBO. DS is going to cogitate and digest the data, I look forward to hearing more, I really can't thank Darkspeed enough, for his time, knowledge, use of his flow bench and most of all his patience with me when I didn't understand. Thanks, DS if you're ever passing this way kettles always on mate. Dan
|
|
Last Edit: Jul 24, 2022 14:12:14 GMT by logicaluk
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
Jul 24, 2022 12:50:41 GMT
|
Hopefully, someone has access to a valve catalogue I'm looking for a valve 1-2mm longer and 1mm wider at the seat
Valve data
inlet length 109.5mm valve width 35.9mm stem 6.58mm collet stem 5.5mm collet cut out 5.5mm offset 5mm from top of valve
exhaust length 110.3mm valve width 32mm stem 6.5mm collet stem 5.5mm collet cut out 5.5mm offset 5mm from top of valve
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
Jul 24, 2022 12:54:52 GMT
|
I also measured the valve lift on the Newman reground cam. inlet 10.62mm Exhaust 9.93mm
|
|
Last Edit: Jul 24, 2022 14:06:58 GMT by logicaluk
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
I have some light bed time reading
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
Couple of hours in the workshop tonight, and for all of you that have never wondered what the in side of an acclaim distributor looks like I stripped it down because it's been running odd, and it sounded rattly like one of the bob weights was loose, but as you can see it wasn't, just the odd running condition that caused them to clack, the bearing race, the advance plate sits in seems fine too, so it was reassembled, and It seems to run better afterwards, not a lot, but a bit better. Just after I put the car away, I thought air leek and spanner checked the carb mounting boots, one of which was not as tight as it could have been, I'll have to wait till tomorrow to find out if that was the cause. Some time ago I lost one of the transponders for the immobilizer, and I've been having kittens about losing the other one, replacements are £25 quid each, or a complete new immobilizer kit is £70 and programme the 2 new transponders to unlock the original unit and have an immobilizer for the next project. It's a Toad Sterling Excel. Dan
|
|
|
|
Darkspeed
Club Retro Rides Member
Posts: 4,681
Club RR Member Number: 39
|
83 Triumph Acclaim, GAME OVERDarkspeed
@darkspeed
Club Retro Rides Member 39
|
|
That's a very Honda dizzy - The C27A has a similar ball race mounted advance/retard plate - if not checked already make sure the vac unit is vac tight, and if it's a cam driven dizzy check the drive "tooth" engagement into the cam end for any slop.
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
Thanks DS, checked the vac advance, and the cam gears are good, it's an almost new dizzy I bought a box of acclaim parts at an autojumble and found a NOS dizzy still in its BL box. Dan
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
I've been thinking about the dead spot just as I tip in to the accelerator, first I thought fuel, but I don't think there is any adjustment on the accelerator pump, so I thought I'll try a different vac signal to the dizzy and altho it's not cured it completely it's much more driveable, Today I'm playing with some Loti, so I'll report back after I've given it a dam good spanking. Dan
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
I'll just leave this here
|
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
Post spanking report, it goes very well, for a 1300, but it's not right. I'm pretty sure it's a fuelling fault, I've tried the different vac take-offs, including no vac advance. The one on the bottom of the carb seems to give the best result, but it still dies on acceleration from idle, I can also hear a definite miss on acceleration from mid-revs. I tried blocking the vac feed to the crankcase ventilation pot, which richened the mixture up and made it more of a stumble than dead spot. The centre arrow is next to the first linkage, which moves with the accelerator when the tag hits the stop the pump leaver stops moving, the pump leaver pivots on the screw and the other end presses on the accelerator pump rod which goes down to the diaphragm. As I need the car tomorrow morning, I'm not going to pull the carbs to check them over, but I have a cunning plan, it involves some rubber hose masking tape and my nuts, 2 x M8 nuts to be precise, and it looks like this The idea being, to stop the accelerator pump pumping by hitting the stop prematurely, if it doesn't work then it's a quick tug to take them off and return it to normal service. From putting Frank away it did feel better, but it was on choke, ill see tomorrow when I'm out on our club run. I've also ordered an AFR gauge, so I can check how the carbs are actually doing. Dan
|
|
Last Edit: Aug 6, 2022 20:52:01 GMT by logicaluk
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
After re-reading my post I had a thought and went out to check a spare set of carbs and found this bodge will limit the travel of the accelerator linkage to 3/4 but if it drives better, then the spring is only held on with a small split pin and should only take 10 mins to remove.
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
I can report it's not the accelerator pump, I disconnected it, and it made no difference. Having spent 200 miles driving around back roads over the weekend, I think all acclaims do it but, its much less noticeable in standard cars, my mods have made it worse, lighter flywheel, freer breathing.
It's only at the first few % of throttle opening, it happens at all revs if the throttle is closed.
Thinking cap on. Dan
|
|
Last Edit: Aug 7, 2022 16:26:25 GMT by logicaluk
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
|
|
|
|
|
|
|
VLC media player opens that first link, it plays REALLY fast, but I'm sure you could pause/slow it down.
|
|
1968 Mini MkII, 1968 VW T1, 1967 VW T1, 1974 VW T1, 1974 VW T1 1303, 1975 Mini 1000 auto, 1979 Chevette, 1981 Cortina, 1978 Mini 1000 1981 Mini City, 1981 Mini van, 1974 Mini Clubman, 1982 Metro City, 1987 Escort, 1989 Lancia Y10, 1989 Cavalier, 1990 Sierra, 1990 Renault 19, 1993 Nova, 1990 Citroen BX, 1994 Ford Scorpio, 1990 Renault Clio, 2004 Citroen C3, 2006 Citroen C2, 2004 Citroen C4, 2013 Citroen DS5. 2017 DS3 130 Plenty of other scrappers!
|
|
|
|
|
It could be not quite enough acceleration enrichment maybe. If it's a bit better under choke then more fuel might help just as you blip the throttle.
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
VLC media player opens that first link, it plays REALLY fast, but I'm sure you could pause/slow it down. Thank you your a bloody genius.
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
It could be not quite enough acceleration enrichment maybe. If it's a bit better under choke then more fuel might help just as you blip the throttle. Unless the choke holds the throttle open enough to be passed it. Then wouldn't disconnecting the accelerator pump make it worse?
|
|
|
|
|
|
|
Both true.
Could it be that the accelerator pump is putting such little fuel in it's not really making a difference? So when you disconnect it it stumbles more, but not enough to actually be noticeable in how it drives.
Is there a little lever you can press to see if it's squirting fuel at all?
|
|
|
|
logicaluk
Posted a lot
Every days a school day round here
Posts: 1,307
|
|
|
The carbs are sidedrafts with trumpets that turn 90deg so only when they're off the car will I be able to check the accelerator pump. Next step it to strip, clean and set them up on the bench see if that makes any difference, then once I've re-read the files Ill try blocking the air cut valves off see how that affects things. I'm going to email Mike Nixon the author of the SWF files for some advice.
|
|
Last Edit: Aug 8, 2022 11:39:10 GMT by logicaluk
|
|
|