[Cliff R]

Dave, the HIC is easily plugged off and typically not a problem as the valve is designed to only open when underhood temps reach a point where a leaner A/F ratio at idle is beneficial. A defective HIC valve could be open and cause a vacuum leak at idle, so it is something to check when troubleshooting idle problems.....Cliff

[old66tiger]

You know, I forgot all about the HIC deal. I remember a long time ago when I was tuning my TP on the 455 that I ended up plugging the HIC because the strip on mine was not even close to seating into the orifice. Anyway, it helped a bit with the idle getting rid of "another" vacuum leak. I think Mike Wasson offers up new HIC's but I figured that I was not going to be standing in stop and go traffic.

My experience with the TP was that I tuned it the best i could to get it to idle somewhat civilized and the manifold vacuum added a few degrees of timing that smoothed out the idle some. Given that my cam was the XE deal and it always idled somewhat poor, but in the end, the 2GC is a rather unsophisticated carb and I was looking for help in all of the places i could.

[gtorich]

Originally Posted by Cliff R

Now i had this set up on my old motor which was the same except 6X heads and a 60919 cam...........now the cam is a roller 235-246 OF from sd and the alum heads.

You do NOT need a vacuum advance to cure this problem. The engine should idle as well as, or even better with the new cam, as it has less overlap and shorter seat timing than the 60919 cam, and the compression should be quite a bit higher with the smaller chamber heads.

I've used both of those cams in 455's with KRE heads. In my old engine at 10.5 to 1 compression, the 60919 cam idled around 11-12" vacuum with noticable lope.

My new engine is slightly higher compression, but idles at 13.5" vacuum, very smooth with slight hint of a "lope", it uses the same 236/245/112 cam you are using.

I use 10 degrees initial timing and no additional timing from the vacuum advance at idle with both engines.

I suspect here that you may have a fundamental problem someplace, vacuum leak, lifter too tight, bad plug wire, spark plug(s), etc.

I've used the 236/245/112 cam in lower compression 455's with aluminum and iron heads, and it idles fine. It does start to get a bit "aggressive" down around 9.5 to 1, but vacuum is still around 11-12" and idle is steady......Cliff

I suspect here that you may have a fundamental problem someplace, vacuum leak, lifter too tight, bad plug wire, spark plug(s), etc.

I suspect here that you may have a fundamental problem someplace, vacuum leak, lifter too tight, bad plug wire, spark plug(s), etc.

Cliff, and Dave, im sending you a pic of the center carb with this, im sure its just the garden varity of 2 bbl. I can replace the plugs & plug wires...........ive check all over for leaks using a propane torch, don"t know if this is a good thing or not, just didn"t want to start squirting starting fluid all over the place.

Would anything improve if i moved the intial up any , im at 12 now.........or would going back to 10 as Cliffs help .

I appreciate all the help im getting from you guys,

Rich

[Tom Vaught]

Is that a tapered rubber stopper installed in the Power Brake fitting hose in the picture?

Very hard to seal tapered rubber plugs. Why was it done that way?

Tom Vaught

[gtorich]

Originally Posted by Tom Vaught

Is that a tapered rubber stopper installed in the Power Brake fitting hose in the picture?

Very hard to seal tapered rubber plugs. Why was it done that way?

Tom Vaught

Tom, all my tests were done with just the center carb on, and the other two had block off plates on them.............i just threw on the other two carbs on to see if that did anything different as far as vacuum was concerned. They were not hooked up to fuel, i just had them sitting there. Proubly should have hooked the front carb up the proper way, getting late and being lazy that day.

As in my previous posts all my issues were with just the center carb and block off plates on...........im gonna dive into this again this week, hopefully things start turning around here for me.

Rich

[gtorich]

Ok, an update for the ones responding to this thread............

Today i put my initial timming to 15-16 btdc, and turned the idle down some........

Car ran pretty good, temp stayed between 170-190 but this was with my elec fan running with the flex fan.............thought this was kind of strange, not that hot today about 80 some, but usually i could run down the freeway with the iron heads and never hit 160 on the temp guage.

Still having a hell of a time keeping the idle at 850-900, checked for vacuum leaks using brake cleaner spraying everywhere, no difference in idle.

Might need a different throttle spring, couple times at a stop sign , it would stay at 1200-1300, but if i lifted the pedal up with my foot it would drop down.

Noticed if i idle the car with new plugs after 5 or so minutes, they were black..........today i ran the car 50 miles, ran it somewhat hard, no smoke whatsoever comming out of my pipes, but the neighbor guy said he could smell the gas from my car, and hes 2 houses away........when i took out these plugs tonite they were somewhat tan/white on the tips and the first ring was kind of a soot black color.

Don"t know if im getting a gas or exhaust smell in the car, but with the windows down and doing 70-80 im smelling something in the car, and eyes are burning some.

Right now im at 0.039 on the idle tubes, 0.076 on the mixture screws, 0.125 on the throttle blades...............

Mike Wasson was good enough to send me another base plate as well as a venturi cluser, so i can start over if you think this would help.

While at 190, i can shut off and start the car instantly, no hesitation at all, did it at least 7-8 times in a row, no issues.

Not sure where to go from here..............hate to dump the tripower after spending quite a bit on the whole deal.

Sorry for the long post & dumb questions, but i hope you understand this is frustrating .......and would like to find out some answers.............didn"t spend $2500 on alumin heads, to run 30 degress hotter than my 6X-8 did.

Rich

[gtorich]

Sorry, forgot to add something to that last post...............if i shut off car at 1000 ish or above on the idle, it usually runs on for a second or two..............if i shut it off at 950 or below..............shuts off good.

The biggest issue im having right now is i can keep the same idle for 20 minutes in a row, its moving where ever it feels like while driving, can set it at 850-----------can even set it at 600 but shakes terrible......................drive it for 10 or so minutes and its always at 1000ish or higher............

if i bllip the pedal, it sometimes drops to where i did have it set at.............but usuall not.

Rich

[Hillard]

Why did you bump the timing up Rich? With 15-16 initial you're going to end up with about 35-36 total which is too much with those heads and a zero-deck. I would put the timing back where I had it and fix the carbs. Quite honestly I'm not sure you'll ever get a tri-power to run right on that combination but I'm not an expert on tri-powers either. I do hope you eventually get it worked out.

[gtorich]

Originally Posted by 1050goat

Why did you bump the timing up Rich? With 15-16 initial you're going to end up with about 35-36 total which is too much with those heads and a zero-deck. I would put the timing back where I had it and fix the carbs. Quite honestly I'm not sure you'll ever get a tri-power to run right on that combination but I'm not an expert on tri-powers either. I do hope you eventually get it worked out.

Hey Dave, i was just frustrated with this whole deal and thought i would try something different........i believe you had it set at 12, im gonna probubly put it back there tomorrow............i must have really been lucky before, for 8 years i really didn"t have much issues with these carbs.........now i can"t get anything right.

But i got to admit the motor is running great, very happy with that end of it.........just wondering if the initial is too high, would that affect engine temp as far as higher temps.........im gonna keep at it though, im like a pit bull, im not giving up yet. LOL

Rich

[grandville455]

Rich I am only running 31 total.. these heads don't need or want alot of timing. have u thought about trying a 4 barrel setup? will it just not idle good? how does it run down the road? responsive etc?

[gtorich]

Originally Posted by grandville455

Rich I am only running 31 total.. these heads don't need or want alot of timing. have u thought about trying a 4 barrel setup? will it just not idle good? how does it run down the road? responsive etc?

Darby............really do not want to go with the 4 bbl set up, i like the trips........guess i gotta keep at it. I turned it back down to 12 initial and i have 18 with the msd for 30 total..........runs pretty good there, although it ran good at 16 initial also.

The motor runs great, responsive, you nail it and there is no hesitation, goes very well.............now i guess i just have to work the bugs out.

One thing i noticed that with these alum heads for some reason the motor is running way hotter than it did with the iron heads........the only changes to the motor were alum heads and roller cam, also different water pump.

With the old iron heads, i couldn"t get that motor up to 160 on the freeway, now with these heads it seems to creep up to 170-180, not that thats bad, just wondering why it won"t run cooler on the freeway............in the city its the same story i had before, always had to run the electric with the flex fan, but that would maintain 180-190 wouldn"t change, now with both fans running its 190-200..........so who knows, and yes i have no fan shroud, but it never had one in 12 yrs.

Once the motor gets somewhat hot, then i have the running on issues, but it only goes for about a second or two.

I only have 150 miles on it so far, so maybe things might get better once i get a few more miles on it..............i

Rich

[old66tiger]

Rich, you are comparing apples to oranges. You are running a much hotter cam, probably higher compression, etc, etc, etc. The last motor is probably not even close to what you have now. FWIW, running down the highway with a 160 stat, I run 180 almost all of the time. If i am pounding on it, I will get up to 190 or almost 200, but it settles back to 180-185. What rad are you running?

Also, I had gone through the issues of tuning a TP for my last setup and you have to remember that the 2bbl is a rather primitive carb. Simple to fix and simple to rebuild, but somewhat finicky when tuning for a large cube motor with a large cam. I know Glen (tripower 455) had his issues with tuning the TP for his motor too and ended up with a large replacement 2bbl. Point being is that you may need to settle on a "good enough" ground and make some small adjustments as you drive it.

BTW, what H2O pump are you running?

[gtorich]

Originally Posted by old66tiger

Rich, you are comparing apples to oranges. You are running a much hotter cam, probably higher compression, etc, etc, etc. The last motor is probably not even close to what you have now. FWIW, running down the highway with a 160 stat, I run 180 almost all of the time. If i am pounding on it, I will get up to 190 or almost 200, but it settles back to 180-185. What rad are you running?

Also, I had gone through the issues of tuning a TP for my last setup and you have to remember that the 2bbl is a rather primitive carb. Simple to fix and simple to rebuild, but somewhat finicky when tuning for a large cube motor with a large cam. I know Glen (tripower 455) had his issues with tuning the TP for his motor too and ended up with a large replacement 2bbl. Point being is that you may need to settle on a "good enough" ground and make some small adjustments as you drive it.

BTW, what H2O pump are you running?

I hear ya Bob...............im just starting to do little adjustments as i drive, put another 50 miles on today..........temps stayed at 180 on the freeway.........

Really not bad, but the only issue thats driving me nuts is this damn run on for a second or two when shutting it off...............now if im in the garage idleing and it gets up to 170, never seems to do it..........180-190 it will, bad part of that deal, it won"t do it everytime. LOL

Now as far as starting the motor warm, no issues at all fires right up. On the water pump, i can"t even remember what i bought, it think it was some cardo brand.....

Noticed today while fooling around, one side of my rad is quite a bit hotter than the other side, so this week, im gonna put a different heater hose on top on, right now my hose sits a little higher than the rad.

I appreciate all the help im getting from you guys, its been a very frustrating summer so far.

Rich

[gtorich]

Originally Posted by old66tiger

Rich, you are comparing apples to oranges. You are running a much hotter cam, probably higher compression, etc, etc, etc. The last motor is probably not even close to what you have now. FWIW, running down the highway with a 160 stat, I run 180 almost all of the time. If i am pounding on it, I will get up to 190 or almost 200, but it settles back to 180-185. What rad are you running?

Also, I had gone through the issues of tuning a TP for my last setup and you have to remember that the 2bbl is a rather primitive carb. Simple to fix and simple to rebuild, but somewhat finicky when tuning for a large cube motor with a large cam. I know Glen (tripower 455) had his issues with tuning the TP for his motor too and ended up with a large replacement 2bbl. Point being is that you may need to settle on a "good enough" ground and make some small adjustments as you drive it.

BTW, what H2O pump are you running?

You asked about the rad i was running, its some cheapy "Howe" alum rad, had it for 12 years now.

Dave Hillard thought the temps would go down some also once i get a few more miles on it............almost got 200 miles on the motor so far, kind of hard not to nail it more, im trying to be a good boy and listen to the CF clutch rules, "Drive nice" for 500 miles..........screw that. LOL............i can nail that baby in 2nd gear and im all over the road, its running real nice. Happy with that, not if only i can shut it off without it running on.

Rich

[Tripower455]

Rich,

Mine will do the "run on" if I have the idle set higher than about 850-900 rpms. Before I was able to get mine to idle right, I got in the habit of stopping it with the clutch or running the AC as I killed the ignition.

180 cruising is nice...... It should run a little cooler as it breaks in.

Keep at the tuning. Make small changes. It is possible to get a good running tripower with these things. Mine's running pretty well nowadays.

I think I recall you mentioning the throttle not returning all the way to idle with your foot off the pedal (maybe it was someone else.... if so, I apologize). I had the same problem running the "correct" yellow tripower spring by itself. I got a smaller OD spring from the parts store, and put it inside the yellow one. That totally solved the problem. It also gives you a measure of insurance if the yellow one breaks.

[goatman65]

I'll add this tidbit.On the end carbs,pass side linkage arms are held on by a screw.If either of those screws is just a little too tight,one or both carbs may not be closing completely.You could try loosening the screws and making sure the butterflies are closing all the way.Sticking open a bit will cause a fast idle or idle that doesn't 'stay put'.
One more thing i had a problem with.I would set the idle,drive a while,and when i came to a stop the idle would be higher than where i set it.I would reset it,drive it,idle would be up again.This went on quite awhile.I checked,rebuilt,adjusted all three carbs,checked for vac leaks,timing,etc...One day i noticed the idle adjustment screw appeared to be screwed in really far,and it was.Turns out the screw was really lose in the hole it is screwed into.While driving the screw would actually turn itself in,from vibration i guess?,and result in a higher idle speed.Just one of those 'odd' things,so maybe check the idle adj screw,if you can turn it with your fingers its probably too loose.Sorry for the long post.

[Tripower455]

Doh, I had the same problem with my original tripower carb. I put a stronger spring on mine to fix it.

Also, on the ends, in addition to the screw, you have to make sure that the throttle blades don't hit the gasket or the hole in the manifold.. There is a little play between the throttle body and the studs, and sometimes, if it's not aligned properly, they will bind a bit, preventing them from closing. I always remove the return spring and make sure that they are free when torquing them down. I put a dot of 3M rubber cement on the bottom of the gasket to keep it centered too.

[gtorich]

Originally Posted by goatman65

I'll add this tidbit.On the end carbs,pass side linkage arms are held on by a screw.If either of those screws is just a little too tight,one or both carbs may not be closing completely.You could try loosening the screws and making sure the butterflies are closing all the way.Sticking open a bit will cause a fast idle or idle that doesn't 'stay put'.
One more thing i had a problem with.I would set the idle,drive a while,and when i came to a stop the idle would be higher than where i set it.I would reset it,drive it,idle would be up again.This went on quite awhile.I checked,rebuilt,adjusted all three carbs,checked for vac leaks,timing,etc...One day i noticed the idle adjustment screw appeared to be screwed in really far,and it was.Turns out the screw was really lose in the hole it is screwed into.While driving the screw would actually turn itself in,from vibration i guess?,and result in a higher idle speed.Just one of those 'odd' things,so maybe check the idle adj screw,if you can turn it with your fingers its probably too loose.Sorry for the long post.

Thanks for that little tidbit of info.................yep, sure sound like what mine is doing, i"ll look into that asap.

[gtorich]

Originally Posted by Tripower455

Doh, I had the same problem with my original tripower carb. I put a stronger spring on mine to fix it.

Also, on the ends, in addition to the screw, you have to make sure that the throttle blades don't hit the gasket or the hole in the manifold.. There is a little play between the throttle body and the studs, and sometimes, if it's not aligned properly, they will bind a bit, preventing them from closing. I always remove the return spring and make sure that they are free when torquing them down. I put a dot of 3M rubber cement on the bottom of the gasket to keep it centered too.

Thanks Glen, more good advice on what to check for. Was wondering what you thought of this deal or anyone else for that matter.

Talked to a guy today and he said maybe your idle isn"t staying where you set it is because the MSD weights are not comming back like they should. He said check you initial when warm, drive the car some and see what the idle is at, if higher than what you set it at, check your initial again and see if it still is at where you set it. Whats ya guys think...................made sense when he told me this, but then again i was on my 5th beer when hearing this. LOL

The MSD unit i have doesn"t have the vacuum can.

Once again i really appreciate the help ive been getting from you guys..........im gonna get this resolved yet.

Rich