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What did you do with your TR7/TR8 today?

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Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1491469 by M1kem3 That looks great! I decided just to ditch the original center caps.

I used Mr. Gasket Chrome Wheel bearing covers for Chevy. I had to use my disc sander to shorten them about 1/16" or so.

They can be pressed in from the front or from the back of the wheel. The photo shows them pressed in from the back. If you press them in from the front they are taller, probably 3/8" taller and very comparable to the OEM caps.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore



Edited 1 time(s). Last edit at 2017-10-20 11:54 AM by Darth V8R.

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Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
Been having a weird problem. The TR8 has been surging at part throttle, sometimes rather badly. Thought maybe the mixture was lean, tweaked it up and no change.

Finally it went nuts on me, it would start fine, but had no power above 2,000 RPM. and anything above 1,000 it was surging. Limped it home, and spent the evening scratching my head wondering what was going so terribly wrong.

It finally hit me that it was acting like the ignition was not advancing. I had installed a Pertronix exact replacement distributor when the OEM unit blew chunks. When I had installed it originally it pinged terribly, and when I disassembled it the weights were stuck in the full advance position. I disassembled it at that time and lubed it up, and all was well.

So I tore into it again, and behold one weight was jammed. A little sleuthing showed that a rivet in the weight was snagging on the mounting plate. The sleeve around the main drive shaft that carries the trigger wheel was loose because the set screw had backed out, which is probably why the weight snagged in the first place. So I ground down the rivet heads to add some clearance, lubed everything, and used loctite on the set screw.

Runs great again, but I must say I am not terribly impressed with the distributor. The used Mallory Unilite Optical Dizzy I used temporarily in the car performed very well, but looked completely unoriginal and a bit scruffy. It had adjustable vacuum advance, which was pretty slick. Maybe I should have stuck with that.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore



Edited 1 time(s). Last edit at 2017-10-20 11:45 AM by Darth V8R.

TR3barton Avatar
TR3barton John Taylor
Greenfield, MA, USA   USA
hub caps are very nice

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TR3barton Avatar
TR3barton John Taylor
Greenfield, MA, USA   USA
hello,

is the part number 2486

robtr8 Rob Stephenson
Lake St Louis, Missouri, USA   USA
In reply to # 1492837 by Darth V8R Been having a weird problem. The TR8 has been surging at part throttle, sometimes rather badly. Thought maybe the mixture was lean, tweaked it up and no change.

Finally it went nuts on me, it would start fine, but had no power above 2,000 RPM. and anything above 1,000 it was surging. Limped it home, and spent the evening scratching my head wondering what was going so terribly wrong.

It finally hit me that it was acting like the ignition was not advancing. I had installed a Pertronix exact replacement distributor when the OEM unit blew chunks. When I had installed it originally it pinged terribly, and when I disassembled it the weights were stuck in the full advance position. I disassembled it at that time and lubed it up, and all was well.

So I tore into it again, and behold one weight was jammed. A little sleuthing showed that a rivet in the weight was snagging on the mounting plate. The sleeve around the main drive shaft that carries the trigger wheel was loose because the set screw had backed out, which is probably why the weight snagged in the first place. So I ground down the rivet heads to add some clearance, lubed everything, and used loctite on the set screw.

Runs great again, but I must say I am not terribly impressed with the distributor. The used Mallory Unilite Optical Dizzy I used temporarily in the car performed very well, but looked completely unoriginal and a bit scruffy. It had adjustable vacuum advance, which was pretty slick. Maybe I should have stuck with that.

Vance


I washed the motor a couple months ago and it wasn't happy right afterwards. I guess it likes to be covered in oil.
When I popped the dizzy cap off the Pertronix to see if water had gotten in there, I found a lot of oil. Cleaned it up and it ran OK.
I noticed it would show very lean until it got warmed up and I came off the choke though.
Then it died on me the other day, coming home from work. Towed it home and tried it a couple days later and it started right up.
Ran it a bit on jack stands yesterday and it died while I was playing with the timing light. I noticed it was running at TDC but would advance just before it died.
Ordered a new Pertronix dizzy (in stock!) and a fuel check valve from Summit, based on this week's conversations in this thread.



1980 TR8
2006 XC90 V8
2008 328xi
2011 XC60 T6 RD

Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
Those are the ones. I noticed you can get taller ones if you wish, but that is the one I used.

If you press them in from behind you will need to shorten them - maybe 3/16".
I pressed them in from the front, and found I still needed to shorten them maybe 1/16" - just enough to get the lip off the cap. Otherwise it was too difficult to press them in.
I used my disc sander clamped in a vise. With my gorilla lug nuts which are also chrome plated, they make for a nice looking package.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

POW Peter Wirth
HEBRON, NH - New Hampshire, USA   USA
In the on going battle to dial in my carb (Holley 390 CFM, list # 8007) I can say I am 95% there. That may well be where it'll stay. Could not get rid of an off idle flat spot no matter what combination of accelerator pump cams and squirters I used. I could make it worse OK, but never better. In addition there was a jerkiness while coasting down hill and at other times with light throttle often as not. Apparently I was chasing 2 problems but expecting one solution. On the recommendation of Holley tech I went up in main jet size from the original fitment of 51 to 54 then to 57. Off idle hesitation and between shifts went away but off throttle jerkiness remained. On a lark I disconnected vacuum advance and now that's gone too. Economy seems about the same so it's all good. Mallory magnetic pick-up distributor is all in at 3000 RPM with a crankshaft timing of 28°, so with my initial at 10° My total advance is 38°. My secondary metering plate has equivalent to 56 jets. That's smaller than my primary for sure. I may go up with the these.

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parrisw William P
Victoria, BC, Canada   CAN
You didn’t speak of the power valve you have in the carb. That is what you need to change to get rid of that flat spot. Likely you need to go to a smaller number.

Will

In reply to # 1493087 by POW In the on going battle to dial in my carb (Holley 390 CFM, list # 8007) I can say I am 95% there. That may well be where it'll stay. Could not get rid of an off idle flat spot no matter what combination of accelerator pump cams and squirters I used. I could make it worse OK, but never better. In addition there was a jerkiness while coasting down hill and at other times with light throttle often as not. Apparently I was chasing 2 problems but expecting one solution. On the recommendation of Holley tech I went up in main jet size from the original fitment of 51 to 54 then to 57. Off idle hesitation and between shifts went away but off throttle jerkiness remained. On a lark I disconnected vacuum advance and now that's gone too. Economy seems about the same so it's all good. Mallory magnetic pick-up distributor is all in at 3000 RPM with a crankshaft timing of 28°, so with my initial at 10° My total advance is 38°. My secondary metering plate has equivalent to 56 jets. That's smaller than my primary for sure. I may go up with the these.

TR8fan Avatar
TR8fan Mike Shultz
Folsom, California, USA   USA
Put new rota wheels on the TR8 today

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POW Peter Wirth
HEBRON, NH - New Hampshire, USA   USA
In reply to # 1493101 by parrisw You didn’t speak of the power valve you have in the carb. That is what you need to change to get rid of that flat spot. Likely you need to go to a smaller number.

Will

In reply to # 1493087 by POW In the on going battle to dial in my carb (Holley 390 CFM, list # 8007) I can say I am 95% there. That may well be where it'll stay. Could not get rid of an off idle flat spot no matter what combination of accelerator pump cams and squirters I used. I could make it worse OK, but never better. In addition there was a jerkiness while coasting down hill and at other times with light throttle often as not. Apparently I was chasing 2 problems but expecting one solution. On the recommendation of Holley tech I went up in main jet size from the original fitment of 51 to 54 then to 57. Off idle hesitation and between shifts went away but off throttle jerkiness remained. On a lark I disconnected vacuum advance and now that's gone too. Economy seems about the same so it's all good. Mallory magnetic pick-up distributor is all in at 3000 RPM with a crankshaft timing of 28°, so with my initial at 10° My total advance is 38°. My secondary metering plate has equivalent to 56 jets. That's smaller than my primary for sure. I may go up with the these.

Right, did not discuss PV. After chasing those numbers am currently running 8.5. Standard is 6.5 and I went in steps to 9.5. 8.5 is the one that works the best. Have a solid 16.5 HG vacuum reading. Plugs are all the nicest shade of off white. I could go down a bit but it seems so right now. As I said the plugs are a perfect color. I don't have headers. I do have higher comp pistons (9.65 : 1) and a bit of a cam. I think my engine is happier with the 8.5 PV and 57 mains than other 3.5's may be. Those specs sound too rich I know but even my tail pipe tips show only very light deposits, almost as clean as modern EFI engine.

Bergie Bob Berg
Powell, Ohio, USA   USA
Peter...do you you know your air fuel read with your problem....also is it a flat spot or stumble...both different and you do opposite things to carb...if your flat spot is lean then you go up on power valve to add the power valves circuit sooner... rich then down on PV to lean Turning on later...I set the power valve off my cruise vacuum reading and not idle...

POW Peter Wirth
HEBRON, NH - New Hampshire, USA   USA
In reply to # 1493173 by Bergie Peter...do you you know your air fuel read with your problem....also is it a flat spot or stumble...both different and you do opposite things to carb...if your flat spot is lean then you go up on power valve to add the power valves circuit sooner... rich then down on PV to lean Turning on later...I set the power valve off my cruise vacuum reading and not idle...

HI Bob,
No I don't, strictly done by seat of pants feel, but yes I do know and have felt the subtle differences between flat spot (lean) and stumble (could be either) I say either because really "flat spot and stumble" are language terms only and can mean the same to some drivers. I can discern the between lean weirdness and rich weirdness if you catch my drift. As I recall, at times I was feeling both lean and rich (too small a squirter and cam, and too much powervalve), and at another time just the opposite (to much squirter and not enough PV. And in regards to your last comment, that is what I did as far as final PV selection was concerned by using a vacuum gauge to watch when the stumble occurred. Like many of us we have a test stretch where we know what to expect and in my case this is a hill that takes me out of town. It's about a 3rd gear hill with a 35 MPH speed limit. The 8.5 PV minimized the hitch the most but would not eliminate it. Apparently still not enough fuel here. Larger jets was the only way to accomplish that and coupled with 8.5 PV, all traces of the hitch, stumble, whatever you choose to call the momentary leanness is gone. The engine now has enough grunt to smoothly attack the hill in 4th at about 37 MPH (It's a nasty bumpy country road).

I'm curious, Bob, what are your specs? You can PM me if you wish. I enjoy talking tuning and carbs, others may too but I don;t want to bore the hell out people either. - Pete

parrisw William P
Victoria, BC, Canada   CAN
A actual air fuel gauge for tuning would be the best. Then you know for sure.

Will

In reply to # 1493158 by POW
In reply to # 1493101 by parrisw You didn’t speak of the power valve you have in the carb. That is what you need to change to get rid of that flat spot. Likely you need to go to a smaller number.

Will

In reply to # 1493087 by POW In the on going battle to dial in my carb (Holley 390 CFM, list # 8007) I can say I am 95% there. That may well be where it'll stay. Could not get rid of an off idle flat spot no matter what combination of accelerator pump cams and squirters I used. I could make it worse OK, but never better. In addition there was a jerkiness while coasting down hill and at other times with light throttle often as not. Apparently I was chasing 2 problems but expecting one solution. On the recommendation of Holley tech I went up in main jet size from the original fitment of 51 to 54 then to 57. Off idle hesitation and between shifts went away but off throttle jerkiness remained. On a lark I disconnected vacuum advance and now that's gone too. Economy seems about the same so it's all good. Mallory magnetic pick-up distributor is all in at 3000 RPM with a crankshaft timing of 28°, so with my initial at 10° My total advance is 38°. My secondary metering plate has equivalent to 56 jets. That's smaller than my primary for sure. I may go up with the these.

Right, did not discuss PV. After chasing those numbers am currently running 8.5. Standard is 6.5 and I went in steps to 9.5. 8.5 is the one that works the best. Have a solid 16.5 HG vacuum reading. Plugs are all the nicest shade of off white. I could go down a bit but it seems so right now. As I said the plugs are a perfect color. I don't have headers. I do have higher comp pistons (9.65 : 1) and a bit of a cam. I think my engine is happier with the 8.5 PV and 57 mains than other 3.5's may be. Those specs sound too rich I know but even my tail pipe tips show only very light deposits, almost as clean as modern EFI engine.

ahum Avatar
ahum Andy Hum
Ottawa, Ontario, Canada   CAN
My TR-7 would not start today not even click, getting into panic mode, as you know how difficult to remove the starter, I hit the solenoid starter with the breaker bar and it did the trick, back to life.
Thank you David Huddleson for the tip.

Bergie Bob Berg
Powell, Ohio, USA   USA
Pete...I used to tune your method with seat of pants feel and had a stretch where I did the same pulls in same gear to see what I had....next level tuning does require Air fuel read to make sure you are not chasing your tail...also the 390 holley I know well from previous experience and it has limits with tune ability by design...you can touch jets, idle screw, power valve, fuel float level, vacuum spring, and accelerator pump cams...you have to balance idle/cruise circuits with wide open throttle(wot) and that's where it gets tricky especially since you cant adjust idle/high speed air bleeds or power valve channel restrictors(PVCR's) on that model carb...you could richen up the jets again but then you may be to rich at wot.....for your situation I would go lower on the idle air bleed(richens idle/cruise circuit-no effect wot) and increase pvcr size orifice(s) but its not adjustable on the 390 carb so you have to richen up the jets than watch wot to make sure you don't go to rich. I would put in a 10.5 PV as a book end and see if turning on the circuit earlier helps...also what pump cam are you using (orange?) ..its a balancing act getting it right and a lot going on so data is your friend if you really want it right........next level is tough w/o a/f reads...you would have to check plugs right after a wot pull before idle circuit changes the color...on my 4.6l I'm using a 59 main jet with a 63 secondary jet for reference but each car is different....this engine does respond well in the leaner end of the power band...(12.9-13.2)


I have the below a/f reader hand held unit and if you don't have catalytic converters you can read the exhaust gas out the tailpipe with a clamp on unit so no need to weld a bung in the exhaust pipe....I tune with the a/f reader and a vacuum gauge in the car.....


LM2 hand held reader :
https://www.summitracing.com/search/brand/innovate-motorsports/part-type/data-acquisition/product-line/innovate-lm-2-digital-air-fuel-ratio-meter-basic-kits?N=400587%2B4294915342&SortBy=BestKeywordMatch&SortOrder=Ascending&autoview=SKU&ar=1

tailpipe adapter for O2 sensor w/o cats:
https://www.summitracing.com/parts/inn-3728/overview/

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