I am swapping a moderate 455 into my 340 Skylark. I am at the stage in my project where I need to choose a radiator. I will be running a 7 blade mechanical fan with a clutch, and a fan shroud from a '71 Electra. I have the original Harrison unit. It is in good shape physically, but I am worried about its ability to keep this bigger engine cool. It struggled to keep the 340 cool at times. I am wanting to swap in an alluminum radiator. I would love to get an expensive Allumitech or something, with an internal transmission cooler, but unfortunately that is not in the cards financially. Pretty much the only radiator I can afford is the ol' Universal fit unit from Jegs/Summit for $150 bucks. People on the board report good results with these, but they do not come with an internal transmission cooler. I can run an external cooler pretty easily, which will handle transmission cooling just fine. But what about transmission heating? I have heard talk here and elsewhere that the stock internal tranny cooler is actually more about heating the tranny fluid to operating temperatures, rather than cooling it. Does anyone have experience running a TH400 with just an external cooler? The transmission will use a stock or near stock converter, and the car will ideally be driven year round, which around here could mean temperatures at or below freezing.
I have a Griffin radiator with no internal cooler. I use this transmission cooler with no problems whatsoever, not even in traffic in this Florida summer heat. I am running a 200-4R trans with a 10" 2,800 stall converter. http://www.summitracing.com/parts/BMM-70268/
I don't know if it'll help much, but Alumitech's running a sale this month. I'll be ordering a radiator from those guys once pay day comes around again. Just google "alumitech sale." They have a post on team chevelle with the details.
I really wish I could go that route. Maybe in a few years. For now, I am stuck with the universal. There has not been an overwhelming response about the dangers of having a transmission run too cool... I hate to just hope for the best though. o No:
I was told by some members of the board that the Rad for a 89 Park ave is a perfect fit in the skylark and its pretty cheap. less than 100 from Orileys. It has a trans cooler too! 2 row alum.
Does it have the plastic end tanks though? I've had enough with the plastic ones seeping after a couple of years. It might be ok if you only need it for a couple of years though.
Well... the thing about that is, that the core support on the '66 Skylark is narrow. They got wide in '68, I believe. Limits my options a lot. The local stores can get a Spectra aluminum shipped in for my car for cheaper than the Jegs one, but it does have the plastic tanks. And I already bought the Jegs one. Reading around I was able to find a lot of turbo diesel truck owners who were running just an external cooler, and having good luck. People also talk about the option to install a valve that is basically a thermostat, for transmissions, which I will also look at.
Mike, If you are interested, I have a Griffin aluminum radiator(25272 x) that i believe was from an F-body GM. It measures 31 x 19 x 3. It is in very good shape and only used for about 2-3 years. I would sell for $85 + shipping. If interested there was a pic of it on the griffin website.
Mike i have been running one of the summit racing radiators for several years in my 64. It has cooled a pretty healthy 455 with absolutely no problems. It has no internal cooler but i have been running a good sized external cooler for the transmission and there have been no problems with that either. The radiator i ordered fit the early skylark core support pretty well and surprisingly was made in the USA. I can't remember the part number but if you search the board you will find a thread where the merits of the Jegs and summit radiators were discussed. I wouldn't hesitate to go this route again if i had to do it again.
Opinions of a old fossil,,,:laugh: :idea2: All metal is best,,,, the more rows of tubes the better,,, external coolers for the trans is best.... take a clue from the factories,,, all police, fire, ambulance equipment has oil coolers on the steering, trans, engine oil ,, ect.... heat is your engines/trans enemy if there is too much of it.... you dont want the trans stone cold , true,,, but it will not run stone cold after warm up.... they will run ''warm''....not cold.... but on a hot summer day,,, under extreme stress, they can overheat, losing the viscosity of the oil... THEY ARE REALLY A HYDROLIC TRANSMISSION,,, no pressure on the oil,,, no movement.... the oil has to stay below a certain temp....that is why there is a trans temp gage on big trucks with a automatic trans....
I've read where some folks are running the tranny fluid thru the radiator cooler and then thru a separate external cooler. The theory is that you get the best of both worlds, heat from the radiator to warm up the trans, but extra cooling when needed from the external cooler. Opinions??? Also, there was a thread on here awhile back about some guy who was having problems with his car laying over at higher RPMs. Seems he found that the external cooler was the cause, I guess by restricting fluid flow. I asked in that thread which cooler he switched to but got no response. So, which external tranny cooler are you guys using successfully??? Hope I'm not hijacking. If I am, let me know and I'll start a new thread.:TU: :beer
I appreciate the offer, Carl. That is an amazing deal. Unfortunately the core support on these early Skylarks allows a radiator no wider than 26 inches, and I don't want to cut mine up .
It was reading from the "best of both worlds" guys that got me wondering about running the internal cooler and the external cooler in series, to get both the heating and cooling effect. I have read more than enough other success stories of people just running an external cooler that I am not going to worry about it. It doesn't really ever get colder than about -10 in Salt Lake... and you won't see my leave the house on days like that, much less leave the house in the Buick. As for restrictions by the oil cooler... it would seem to me that as long as you are running a sufficient amount of tranny fluid, and a cooler with reasonably sized tubing, you'd be very unlikely to have a problem with flow restrictions. o No: . I'm no expert, for sure, but like Doc said, a whole lot of people use external coolers, if one was inherently flawed in that way it probably would not last long on the market.
I've got the Jegs aluminum radiator in there now, and a $50 transmission cooler. I clearanced the radiator top plate some near the filler neck, but other than that the rad was a bolt in. Pretty happy with it, though I have yet to see if it actually cools. When I went to do the initial break in, I started seeing gushing water out of the bottom of the passenger fender. Which is where the AC core drains to, and the heater core drains to the AC. So I got sidetracked from the whole thing to work on the heater core project, which is now involving a replacement of the carpet and firewall insulation, a total rebuild of the vent and blend doors... probably going to end up as a full blown interior restoration, the way these "while I'm at its" can go. Hopefully I can get back to the break in soon, and let you know the outcome.
