Machine Gun Posted October 28, 2022 Share Posted October 28, 2022 Background: I recently replaced the stock two-row radiator in my Skylark V8 with a three-row unit, and replaced the stock four-blade fan with a six-blade, non-clutch fan in preparation for my cross-country trip last month. I upgraded the cooling system to better deal with the desert heat. The water pump is three years old, and I have a 180 degree thermostat installed. Performance: The coolant temperature never got over 195 degrees while the car was in motion, even when temperatures in the Mojave Desert were approaching 100 degrees. Coolant temperature usually remained at 190 degrees or lower in all other weather conditions even when temps were in the high-80s, again when the car was in motion. Problem: During periods of extended idling, even with outside temps in the low-70s, the temperature rose to 230 degrees after sitting in traffic for about ten minutes. Fortunately on those occasions I was able to get out of traffic before I had to shut down the engine. It never boiled over. Assessment: It seems clear to me that the fan isn't providing enough air flow when the car is sitting. The fan shroud is in place, the replacement fan is the same diameter as the stock fan, and I put the stock fan back on to see if the blade pitch might have something to do with it. No difference. Next steps: Electric fan? High-capacity water pump? Buy a Studebaker? Link to comment Share on other sites More sharing options...
JohnD1956 Posted October 28, 2022 Share Posted October 28, 2022 did you seal the gap between the radiator and the shroud? Are you certain the vacuum advance unit on the distributor is holding a vacuum and working? 1 Link to comment Share on other sites More sharing options...
NTX5467 Posted October 28, 2022 Share Posted October 28, 2022 Not to sound flakey, but when was the last time the block freeze plugs were knocked out, cleaning out the block's water passages, and replace the freeze plugs? Additionally, at what hot base idle speed is this happening at? AANNDDDD, a possibly big side issue, which was was the car headed, into the wind or away from the wind? Base timing to spec, or retarded to better tolerate current fuels? By observation, GM did a very poor job (compared to Chrysler, for example) of getting more air throuigh the radiator than around it. Gap between the top of the core support and the hood, for example, Chrysler had a flap of rubber on the hood to keep air from going over the core support, for eample. By the same token, some thing masticated rubber can be cut to seal the sides of the radiator and core support, too. Just some thoughts, NTX5467 Link to comment Share on other sites More sharing options...
rodneybeauchamp Posted October 28, 2022 Share Posted October 28, 2022 9 hours ago, Machine Gun said: Background: I recently replaced the stock two-row radiator in my Skylark V8 with a three-row unit, and replaced the stock four-blade fan with a six-blade, non-clutch fan in preparation for my cross-country trip last month. I upgraded the cooling system to better deal with the desert heat. The water pump is three years old, and I have a 180 degree thermostat installed. Performance: The coolant temperature never got over 195 degrees while the car was in motion, even when temperatures in the Mojave Desert were approaching 100 degrees. Coolant temperature usually remained at 190 degrees or lower in all other weather conditions even when temps were in the high-80s, again when the car was in motion. Problem: During periods of extended idling, even with outside temps in the low-70s, the temperature rose to 230 degrees after sitting in traffic for about ten minutes. Fortunately on those occasions I was able to get out of traffic before I had to shut down the engine. It never boiled over. Assessment: It seems clear to me that the fan isn't providing enough air flow when the car is sitting. The fan shroud is in place, the replacement fan is the same diameter as the stock fan, and I put the stock fan back on to see if the blade pitch might have something to do with it. No difference. Next steps: Electric fan? High-capacity water pump? Buy a Studebaker? Jim, I am going thru similar problems with my ‘63 Skylark 215. I think that the issue was an airlock in the cooling system (read heater core). Was able to eventually burp the system by filling the core with one heater hose disconnected. Was amazed how much extra coolant it took 😀😀😀😀 I was thinking like you about shrouds and fans but if everything is clean and working, it should not overheat. My temperature gauge was sitting in the 200-220 range in stop start traffic on a very moderate day, yet as soon as it gathered speed, it would cool back to 180F and lower with 180 degree thermostat fitted. I pulled the pump and thermostat and flushed it thoroughly with a garden hose and found very little debris. Radiator had been recored about seven years ago but had it checked not that long ago. Checked cap was holding and releasing pressure , all good! I put it down to incompetence in the mechanic that I use. Never thought these cars had air lock issues thinking that was more the problem with modern stuff. Heater was giving little heat so in the process of trying to unblock that. Just my thoughts Rodney 😀😀😀😀😀😀 Link to comment Share on other sites More sharing options...
Machine Gun Posted October 28, 2022 Author Share Posted October 28, 2022 @JohnD1956Yes, I sealed the gap between the radiator and the shroud. As for the vacuum advance, I will check that. I know it works because I can see the timing change when using a light, but whether it's working properly is something I need to check with a vacuum pump. Will do when I can. @NTX5467I have no idea if or when the Welch plugs were replaced. Certainly not while I've owned the car. Base idle speed is per factory spec. When things start getting out of hand I put the car in neutral to increase the idle speed to increase air flow and take the load off the transmission. That manages the temperature increase somewhat. Into the wind or away from it? Not sure where you're headed with that question. There's no issue at all when the car is in motion, say around 25 mph or greater. Base timing is set to spec. @rodneybeauchampI will bleed the cooling system when I can. I have to admit that's a step that I overlooked when I installed the new radiator a few months ago. I'll report back after I check into the above items. Thanx for your suggestions. 1 1 Link to comment Share on other sites More sharing options...
EmTee Posted October 28, 2022 Share Posted October 28, 2022 12 hours ago, Machine Gun said: The water pump is three years old... Where did you get the water pump? Did you happen to compare it (esp. the impeller) to the original? What happens when you drop a shop rag in front of the radiator when the engine is idling? Does it get sucked into the core? How much resistance is there to removing the rag from the front of the radiator when you lay it flat on the front of the core? If there's strong airflow through the radiator at idle then it seems low/weak low RPM coolant flow would be the next thing to look at. That could be a pump issue or blockage/restriction somewhere. Maybe try shooting the exhaust manifold with an IR thermometer to compare temperatures... 2 Link to comment Share on other sites More sharing options...
Machine Gun Posted October 28, 2022 Author Share Posted October 28, 2022 Here's an update regarding a few things I had time to do today. I'm starting with the easy things, of course. First I went through the procedure to bleed the cooling system. There wasn't an obvious escape of air or a reduction in coolant level after about ten minutes of idling with the radiator cap removed. The temperature rose only to about 185 degrees during that time. Next I checked the dwell and timing. The dwell was only one degree off (31 instead of 30), so I let it be. The ignition timing had advanced to about 8 degrees BTC, so I reset it to the spec of 5 degrees. The vacuum advance seems to be working because there was a noticeable decrease in engine speed when I disconnected the vacuum hose to set the timing. I haven't yet checked the centrifugal advance weights. @EmTeeI don't recall where I got the water pump, and I did not compare it at the time to the one I pulled out. I rechecked the idle speed per the manual, and it was where it should be (about 550 RPM with the auto trans in gear). Next I did the rag test. I was not impressed with the result. The rag didn't get sucked into the core, but it would stay there if I put it there. The resistance required to remove it was minimal, which leads me to believe that my problem is primarily related to air flow through the core. Why that would be the case with a fan shroud in place and sealed along the edges is a mystery to me. I had originally thought that the thicker radiator core would present more resistance to air flow, which is why I installed a larger fan (six blades vs. four). Apparently that didn't do very much. I'll put the larger aftermarket fan back on and compare the airflow to the stock fan. Fall temperatures have arrived here in NJ, with daytime highs predicted only to reach the 60s for the foreseeable future. I may have to wait for Spring to do further troubleshooting. As always, I appreciate all your comments and suggestions. 2 Link to comment Share on other sites More sharing options...
EmTee Posted October 28, 2022 Share Posted October 28, 2022 Good progress today, Jim! The 'rag test' was with the OE 4-blade fan, not the aftermarket one, right? I agree with you that the 3-row core would likely offer more resistance to airflow than the original 2-row did. That's why (I think) GM would have used a 5 (or 6) blade fan with thermal clutch on a 3-row HD cooling setup, such as with A/C equipped cars. Link to comment Share on other sites More sharing options...
NTX5467 Posted October 29, 2022 Share Posted October 29, 2022 Driving into the wind would help air flow through the radiator. Driving with or having a tailwind means the fan would be on its own to initiate air flow through the radiator. How much vacuum is at the vac advance port on the carb? Usually, it should be minimal and not enough to advance the vac advance at hot base idle. But too much advance while running would tend to cause pinging or worse on the road. Just some thoughts, NTX5467 Link to comment Share on other sites More sharing options...
rodneybeauchamp Posted October 29, 2022 Share Posted October 29, 2022 10 hours ago, Machine Gun said: Here's an update regarding a few things I had time to do today. I'm starting with the easy things, of course. First I went through the procedure to bleed the cooling system. There wasn't an obvious escape of air or a reduction in coolant level after about ten minutes of idling with the radiator cap removed. The temperature rose only to about 185 degrees during that time. That’s the method I used first up but found by removing the heater hose was way more effective. Then the last time I bled the system I disconnected the top heater hose and filled the core until it ran out the top outlet then reconnected everything back up. That way I was sure that I had gotten rid of all the air. It surprised me how much was trapped inside. Once air is trapped inside all it wants to do is expand with the heat. Forcing it out by having the fill level higher than the radiator inlet was the only way it was going to shift. Rodney 😀😀😀😀😀 1 Link to comment Share on other sites More sharing options...
Machine Gun Posted October 29, 2022 Author Share Posted October 29, 2022 11 hours ago, EmTee said: Good progress today, Jim! The 'rag test' was with the OE 4-blade fan, not the aftermarket one, right? I agree with you that the 3-row core would likely offer more resistance to airflow than the original 2-row did. That's why (I think) GM would have used a 5 (or 6) blade fan with thermal clutch on a 3-row HD cooling setup, such as with A/C equipped cars. Yes, the rag test was with the stock fan. I'll put the aftermarket six-blade fan back on the car and do another rag test to compare the two. I did look into a clutch fan before I decided on the one I'm now using but I didn't see any advantage to it other than it would not provide any load when things are relatively cool, like when moving along. My thought was there would be no, or minimal difference between an engaged six-blade clutch fan and a six-blade mechanical fan at idle. Considering that GM used a clutch fan, perhaps there's something I'm missing with the whole fan thing. 1 Link to comment Share on other sites More sharing options...
Machine Gun Posted October 29, 2022 Author Share Posted October 29, 2022 8 hours ago, NTX5467 said: How much vacuum is at the vac advance port on the carb? Usually, it should be minimal and not enough to advance the vac advance at hot base idle. But too much advance while running would tend to cause pinging or worse on the road. I will check the manual for any related specs on the amount of vacuum and/or advance presented to the distributor. 1 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted October 29, 2022 Share Posted October 29, 2022 (edited) If "It never boiled over" I would not be concerned with a extended idle temp of 230. Edited October 29, 2022 by avgwarhawk (see edit history) Link to comment Share on other sites More sharing options...
Machine Gun Posted October 29, 2022 Author Share Posted October 29, 2022 10 minutes ago, avgwarhawk said: If "It never boiled over" I would not be concerned with a extended idle temp of 230. True, with no boil-over or coolant loss at 230 degrees it technically didn't overheat. However, the temperature stopped rising at 230 degrees only because in both instances the traffic started moving along and things soon lowered back down to 195 degrees. I'm concerned primarily because I don't know if the temperature would have stabilized at 230 degrees or would have continued to rise up to the theoretical boiling point of the coolant around 245 degrees when under 16 lbs. of pressure. Regardless, 230 degrees, even if stabilized, is too close to the edge of my comfort level. I also like to keep the auto trans as cool as possible. Link to comment Share on other sites More sharing options...
avgwarhawk Posted October 29, 2022 Share Posted October 29, 2022 (edited) I would then recommend an electric fan on a toggle switch. Use when necessary. However, in doing so it is only masks the underlying issue. Referring to my 54, not until the heads were replaced with cleaned up heads did my run hot issue get resolved. But even so, at idle the gauge climbs to H. My 401 in the 60....no gauge. Who the heck knows what it's doing at idle in 100 degrees. No boil over. Guessing it's good. Edited October 29, 2022 by avgwarhawk (see edit history) 1 Link to comment Share on other sites More sharing options...
KAD36 Posted October 30, 2022 Share Posted October 30, 2022 (edited) When adding AC to my car, there were a couple of experiments on fans and airflow that old tank and I did.. BLUF answer to keep the car coolest at hot idle was (starting with most effective) 1) 6 blade mechanical aftermarket fan 2) HD clutch fan with larger than stock diameter 5 blade fan from 79 Olds 3) bump the idle up to about 650-675 in D. 4) advance base timing about 2-3 deg. 2-4 are what I’m currently running with no issues. My car had similar thermal issues even before the AC, creeping up until it buried the needle on H at idle in D after a highway run, then stuck in traffic on a 95 deg day. N on my gauge is about 200, H is about 225-230. Maybe this is how it was supposed to work back in the day and I had put up with it for many years until I figured enough is enough - plus some cooling margin was required to be built in for adding the AC. The radiator is HD (stock replacement) 3 row. Might add another step, although more investment, is an aluminum radiator; usnavystgc had good results putting one in his 56. I know yours is different than a 55 but consider the above data points if you want to explore options. I briefly considered electric fans but didn’t want to upgrade the stock electrical system to handle the extra load of the AC plus engine fan. Good luck, interested in what you decide. Edited October 31, 2022 by KAD36 (see edit history) 2 1 Link to comment Share on other sites More sharing options...
Machine Gun Posted October 31, 2022 Author Share Posted October 31, 2022 @KAD36I have the problem with a six-blade aftermarket fan on the car. It's the same diameter as the stock fan, but I'm thinking of installing a larger diameter fan as the shroud can accommodate a fan 2" larger. However, the weather is too cool right now to do any more testing. I'll table the project until next year when temps get back into the mid-70s or higher. It's all good for now. Thanx for your input. 1 Link to comment Share on other sites More sharing options...
ol' yeller Posted October 31, 2022 Share Posted October 31, 2022 Just an off the wall suggestion but is your fan close to the radiator? If it’s too far away, that could be an issue. Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted October 31, 2022 Share Posted October 31, 2022 I once had a belt slipping and making NO NOISE. Pulley on the generator sure got hot. Ben 1 Link to comment Share on other sites More sharing options...
KAD36 Posted October 31, 2022 Share Posted October 31, 2022 12 hours ago, Machine Gun said: as the shroud can accommodate a fan 2" larger Likewise. My stock fan was 17 and what fit in the shroud was a 19 ish while still giving ~1/4 inch clearance which has proven plenty IMHO. All that had to be done was shift the shroud down ever so slightly to better center it around the fan. The shroud bolt heads actually cover the elongated mounting holes. The only time the fan rubs the shroud is during a full throttle launch when that deceptive little 322 twists the frame and crimps the body panels. HA! That trail of dynaflow fluid and broken parts heading in the direction of the nearest BBQ joint is mine….🤣🤣🤣 2 2 Link to comment Share on other sites More sharing options...
Machine Gun Posted November 1, 2022 Author Share Posted November 1, 2022 @avgwarhawkAn electric fan, for a variety of reasons, would be my remedy of last resort. I'm not ruling it out, though. @ol' yellerI'm not sure how close to the radiator the fan is supposed to be. The fan spacer between the fan hub and the pulley is 3/4", the fan hub is 5" from the radiator, and the closest part of the fan blades is 3-3/4" from the radiator. As far as I know, no modifications were done that would have altered the distance between the radiator and the fan. My issue is probably due to other factors. @KAD36My shroud is 20" across, so I could go with e 19" fan if I was inclined to do so to maximize the ability of the fan to draw through the radiator instead of partly through the shroud. @Ben Bruce aka First BornA slipping belt on the water pump pulley seems unlikely based on what I can see, but as I'm fond of saying, if you don't know what the problem is, you can't say what it isn't until you check. I'll give a closer look when I can. All: It's possible that all of my angst is related to knowing too much. Had I not installed a temperature gauge I might never have known abut the temperature climb. Assuming that my temps would never have raised above 230 degrees (and I don't know that for sure) my temperature light would never have come on, and I would have been fat, dumb, and happy. All this might be much ado about nothing, but 230 degrees is higher than I want to see. I will continue to pursue reasonable means to reduce the temperature. As I indicated in an earlier post I'm not going to spend any more time on this issue until the warmer weather returns when I can evaluate any remedial actions I might take. Again, thanks for your thoughts and suggestions. 1 Link to comment Share on other sites More sharing options...
avgwarhawk Posted November 1, 2022 Share Posted November 1, 2022 Concerning the shroud, although useful it was not always employed on Buick cooling systems(60' Electra 401). Just a 4 blade fan behind the radiator. These Buicks did/do not display overheating issues. For test purposed remove the shroud and see if the cooling is affective. Link to comment Share on other sites More sharing options...
misterc9 Posted November 12, 2022 Share Posted November 12, 2022 Normally your fan blade should be half in and half out of the fan shroud. Link to comment Share on other sites More sharing options...
Barney Eaton Posted November 12, 2022 Share Posted November 12, 2022 It looks like all the engine cooling areas have been addressed. Go one step further and add an auxillary transmission cooler. I recall "desert" being said and heat kills transmissions. add the transmission cooler after it comes out of the radiator. The transmission will be cooler and likely the fluid going to the radiator will be cooler.... that reduces the load on the engine cooling. I buy coolers at the pick n pull..... look for trucks with the trailer towing package and they have a nice big cooler. Around here I never pay more than $25 for a cooler . Do not mount the cooler against the radiator....make some brackets and suspend it 3-4 inches in front of the radiator. 2 Link to comment Share on other sites More sharing options...
Machine Gun Posted November 12, 2022 Author Share Posted November 12, 2022 @misterc9The fan is positioned in the factory configuration, where the engine side of the fan is flush with the engine side of the shroud. @Barney EatonI installed an auxiliary transmission cooler before I left on my cross-country trip. It's in series with the radiator cooler, installed after the cooled fluid leaves the radiator. I bought a used one from one of the members on this forum, and I think I paid $15 or $20 for it. 1 Link to comment Share on other sites More sharing options...
JohnD1956 Posted November 14, 2022 Share Posted November 14, 2022 On 11/12/2022 at 9:58 AM, Machine Gun said: @misterc9The fan is positioned in the factory configuration, where the engine side of the fan is flush with the engine side of the shroud. @Barney EatonI installed an auxiliary transmission cooler before I left on my cross-country trip. It's in series with the radiator cooler, installed after the cooled fluid leaves the radiator. I bought a used one from one of the members on this forum, and I think I paid $15 or $20 for it. Two things. The fan is supposed to be half in and half out of the shroud. Not flush with the engine side of the shroud. You might need a different length spacer. And I suggest for maximum trans and engine coolant efficiency the auxillary cooler should be the primary path for the trans fluid. The worst case that way is the trans fluid is actually warmed up by the radiator, which would in essence lower the coolant temperature a slight bit. But thats just my theory. Link to comment Share on other sites More sharing options...
Machine Gun Posted November 15, 2022 Author Share Posted November 15, 2022 22 hours ago, JohnD1956 said: Two things. The fan is supposed to be half in and half out of the shroud. Not flush with the engine side of the shroud. You might need a different length spacer. And I suggest for maximum trans and engine coolant efficiency the auxillary cooler should be the primary path for the trans fluid. The worst case that way is the trans fluid is actually warmed up by the radiator, which would in essence lower the coolant temperature a slight bit. But thats just my theory. Thing One: Yes, @misterc9also noted the proper position of the fan with respect to the shroud. The heavy-duty radiator I installed last Spring is one row wider than the stock radiator, but to be honest I didn't notice the position of the fan with respect to the shroud before I removed the stock radiator. My plan when the warm weather returns is to first see if my most recent bleed of the cooling system will have any effect on the temperature at extended idle. If no joy there, which frankly I don't expect, I'll then look for a smaller spacer to get the fan in the proper position within the shroud. I hope that fixes things. If not, then I'll weigh other options. Installing an electric fan, while I won't rule it out, would be my choice of last resort. Thing Two: I will likely leave the transmission cooler installation as-is. While I think your theory has merit, my gut tells me that re-routing the transmission fluid as you suggest won't make enough of a difference. Ideally I'd like to realize at least a 20 degree drop at extended idle in hot weather (from 230 degrees to 210). Whether that's a realistic expectation with my current setup remains to be seen. The coolant has never reached above 195 degrees while the car was in motion, even in the hottest conditions I encountered (outside temps in the high-90s). 1 Link to comment Share on other sites More sharing options...
NTX5467 Posted November 16, 2022 Share Posted November 16, 2022 (edited) After watching the trans oil temp display on the new GM pickups I've been driving for several years now, the atf temp will parallel the engine coolant temp, but slower to come up, in normal driving. Most higher transmission fluid temps are generated in the "over-run" situation rather than "under power" operational modes. Think descending a looonnnggg mountain grade in low gear, using only engine braking to control your speed . . . worse with a load, as in a loaded dump truck. Therefore, as long as the trans is not slipping and turning the atf dark, should not be an issue. ATF used to start to degrade with extended temps of 270 degrees F, but I suspect a syn fluid would best that a good bit. So unless the radiator does start to boil over with a good cap, should be no worries? Would a slipping fan belt also compromise the rotational speed of the alternator, compromising the charing system, too? Just curious as I don't know the belt routing on that engine. I suspect the water pump would put less strain on the belt than a power steering pump at full lock, against the stops? To me, a key issue is . . . does/will the temp keep on rising past 230 degrees F? Or is that where "you got excited and sought to decrease it from there"? IF it will keep on rising from 230 degrees F, THAT would be a red flag to me. But if it stabilizes there and goes no higher, that might not be quite so bad? I know it would not be factory correct, but to me, upgrading to an OEM-style composite radiator might be needed. If one of the correct size (crossflow with the radiator cap on the side rather than in the middle) can be found. From a "right source", they used to be available at about $100.00 new. Having that much more cooling efficiency might tell the story of heat dissipation in that area, I suspect. When I put one in my '77 Camaro 305, it took 45 minutes for the 180 degree F thermostat to open on a 75 degree day. If one for a VW Scirocco can cool a drag race 454, a larger one ought to work well in a normal engine. I suggest this as a method of diagnostics. Just some thoughts, NTX5467 Edited November 16, 2022 by NTX5467 (see edit history) 2 Link to comment Share on other sites More sharing options...
Bloo Posted November 16, 2022 Share Posted November 16, 2022 Have a good look at how close the fins of your water pump impeller run in relation to the timing cover. 1 Link to comment Share on other sites More sharing options...
Machine Gun Posted November 17, 2022 Author Share Posted November 17, 2022 (edited) @NTX5467In both instances of creeping coolant temperatures, it didn't rise above 230 degrees because traffic started moving around the time the temp reached that level. I can't say with confidence that it would have stopped there or would have continued to rise. I doubt that the transmission suffered any ill effects because the fluid looks good, and there's no hint of an unusual odor with it. I found no evidence whatsoever that the belt is slipping. FYI, the engine has two belts off the crank pulley. One drives the fan/water pump and the alternator, and the other drives the PS pump. Another radiator? Not gonna happen. Unless I'm unaware of 300 c.i. Buick engines in Skylarks having a history melting down back when, I see only two broad possibilities: One is that there's an issue somewhere that's already been covered by the myriad suggestions I've already received, and I just need to find it. Two is that there is no problem, and I would not be going through this exercise had I not installed a temperature gauge in the first place. If the idiot light would not come on until the coolant reached 245 degrees as some have suggested, we would not be having this discussion. Information is vital, but TMI can cause problems. @BlooI'll make that determination after I exhaust all of the "easier" investigative options. Again, I'm not going to touch the car again until Spring. Edited November 17, 2022 by Machine Gun (see edit history) 1 1 Link to comment Share on other sites More sharing options...
Machine Gun Posted April 15, 2023 Author Share Posted April 15, 2023 Here's an update to my rising coolant temperature at extended idle. I believe that @misterc9 and @JohnD1956 nailed it regarding the position of the fan with respect to the shroud. As I noted in earlier posts, the new thicker radiator set my fan flush with the shroud. Last week I took @EmTee's suggestion did the rag test with the fan in that position. I then removed the 3/4" spacer that allowed the fan only halfway into the shroud and redid the test. There was a significant increase in airflow with the spacer removed. While I was messing around with other things under the hood I noticed that the slow idle switch on the dashpot wasn't working so I replaced it. I don't know whether that would have any impact on cooling at idle, but it's now working properly with the transmission pitch as it should be. Results to date: I traveled to NC and encountered temperatures in the mid-80s and found myself in a couple of situations where I was stuck in traffic. The coolant temperature never rose beyond 215 degrees. It didn't seem to want to creep much higher, if at all. Compared to the 230 degree temperature I experienced last year under similar circumstances, I'm more than satisfied if it continues to behave itself. I'll be continuing south to SC before heading for home next week, so I'll have other opportunities to test things out. As always, I appreciate all the helpful comments I received. 3 2 Link to comment Share on other sites More sharing options...
EmTee Posted April 16, 2023 Share Posted April 16, 2023 Nice work! Glad to hear that you have this one nailed. How did the new carburetor perform? Link to comment Share on other sites More sharing options...
Machine Gun Posted April 16, 2023 Author Share Posted April 16, 2023 The new carb performs well, but differently as you might imagine. No more vomiting fuel out the bowl vent of course, but there are two things I'm not thrilled with. First, the car no longer starts from cold like it did with the 2GC. With the stock Rochester, one pump to set the choke was all it took for the car to fire up after cranking without having to touch the accelerator again. The Holley choke will set fully with one pump, but no amount of cranking seems to get the engine to fire up without hitting the accelerator once or twice afterward during cranking. Apart from that, it works fine from cold to hot. Am I picking a nit? For sure. Then there's the electric choke, which behaves differently from a conventional choke. I won't bore you with the details, but its behavior after the car has been sitting for a short time but hasn't cooled to the point where I need the choke again, doesn't thrill me. Apart from those two nits, I'm happy with the carb. I'm willing to put up with a lot as long as I no longer have to mop up fuel from the top of the engine. The hardest part of installing the Holley was matching up the dashpot. I had to fabricate a bracket to get the dashpot to hit the proper point on the carb. The throttle linkage and kickdown switch matched up pretty easily. 1 2 Link to comment Share on other sites More sharing options...
NTX5467 Posted April 17, 2023 Share Posted April 17, 2023 (edited) Ford used some factory dashpots on their 2bbls, whether Ford or Holley. Perhaps something like that might fit better? NTX5467 Edited April 17, 2023 by NTX5467 (see edit history) Link to comment Share on other sites More sharing options...
Machine Gun Posted April 17, 2023 Author Share Posted April 17, 2023 The dashpot on the stock 2GC wasn't mounted on the carb, but instead was mounted on a bracket that was bolted to the intake manifold under the coil. I used the same mounting arrangement. It's all good now. 1 Link to comment Share on other sites More sharing options...
rodneybeauchamp Posted May 6, 2023 Share Posted May 6, 2023 On 10/29/2022 at 7:35 AM, Machine Gun said: Here's an update regarding a few things I had time to do today. I'm starting with the easy things, of course. First I went through the procedure to bleed the cooling system. There wasn't an obvious escape of air or a reduction in coolant level after about ten minutes of idling with the radiator cap removed. The temperature rose only to about 185 degrees during that time. Next I checked the dwell and timing. The dwell was only one degree off (31 instead of 30), so I let it be. The ignition timing had advanced to about 8 degrees BTC, so I reset it to the spec of 5 degrees. The vacuum advance seems to be working because there was a noticeable decrease in engine speed when I disconnected the vacuum hose to set the timing. I haven't yet checked the centrifugal advance weights. @EmTee As always, I appreciate all your comments and suggestions. Just rereading the post, my ‘64 Skylark 300 HIgh Compression with power pack four barrel carburettor timing was set at 2 and 1/2 degrees. Rodney 😀😀😀😀😀😀 Link to comment Share on other sites More sharing options...
Machine Gun Posted May 7, 2023 Author Share Posted May 7, 2023 @rodneybeauchampMy timing is set to 2-1/2 degrees, at it should be. Back in October when I wrote that post I had misread the manual and set the timing at 5 degrees, which is the spec for the V6. I corrected my mistake shortly thereafter. Thank you for the reminder! 1 Link to comment Share on other sites More sharing options...
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