200 deg is not that hot so if its running poorly at 200 deg you have other carb/tuning/or maybe fuel line too close to exhast/motor heating it up too much casuing issues.
I have seen plenty of street perf bbcs get to 215-222 deg in traffic which i admit is too hot but they were still running ok at 220 deg so 200 isnt so hot it should make your motor run poorly so keep that in mind too.
Yes,some of the what may be even hotter bbc's then yours you see doing well /running cooler then your in same situations may be running a stock 3-4 core rad or AL rad but with a stock shroud,stock 7 blade clutch fan with hd fan clutch (not std udty,too weak IMHO & a Exp with them) used for a GM ac or hd cooling option that can often out cool/pull more CFM thru the rad then your avg elec fan setup can realistically do.
I see so many setups running cheap aftermaker AL rads and elec fans that dont do well with some setups like in your case and when people went back to the above mentioned stock type cooling setup with a stock 3-4 core rad of better quality AL rad like an Alumitech from Don their running hot issues were gone.
The AL rads have their place thats for sure but some setups dont do well with AL rads from like northern with possibly marginal elec cooling fan capacity.But an alumitech rad from Don is a different story,its a hi quality great looking and great cooling rad that looks stock when painted blk as compaired to most other AL rads.
Your timng should not be an issue but at 16/36 if your cam is pretty stout 16 base is kinda weak with a decent or oht perf cam . Id run at least 18 base for 38 total and see how it responds to that as long as it doesnt ping on 93 fuel.
BTW,i just did a post in the engine forum for a hot running bbc and some of it should apply to your sitiation so i pasted it blow for you to check out,hope you can get something from it other then a headache reading all of it/LOL!!!!!.
Scott
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Re: Hot big block...help!
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A 160 stat will help at 1st but it will only delay the enevitable temp increase if there are any other issues with the coolng system like for ex running a std duty fan clutch that margianl with some bbc setups in traffic on hot 90 deg days,retarded base timing with perf cam,tuning ,radiator is clogged/dirty or just old worn out,etc. which i will cover below in more detail.
Also,if you had the rad overfilled when cold the coolent expands a lot when hot and will puke out every time .
The proper coolent lvl is 2.5-3" below the filler neck with motor cold,any closer to the filler neck then that and it will puke every time you shut it down esp on a hot day.
But to start with 200 deg f or a little more like 210 deg on a hot 90 deg day in traffic for a a while isnt all that bad with a street perf bbc,but i think we can do better and heres how.
Ok,here we go with suggestions assumng the water pump,180 deg t-stat,and rad are all ok and up to proper operating capacity & enough to handle cooling your motor setup to begin with.
With perf cam ensure your runnng enough base timing like at least 16-18 deg aong with vac adv for street motor too.
Retartded base timing and no additional timing from vac adv for a street perf motor @ idle will also increase in traffic/idle temps too so keep that in mind.
Lean idle mixture setting can also inc idle temp a little too so chk tha out too.
Also,std duty fan clutches that most people run can be maginal at times for some street perf bbc motors esp on ht day in traffic. I find the std clutches dont lock up enough for good cooling ,thats why i run the HD fan clutch on my mild 69 bbc and have also instaled them on other 69-70 bbc chevelles i have worked on too with great success in lowering temps.
Every time i replaced a good working std duty clutch with a new hd clutch i got a noticable reduction in temps tesp in traffic which was really helpfull. Thats simply because the hd clutch locks up a litte more for more fan rpm at idle which = more airflow thru rad when the motor needs it most when stoped at idle. But the HD fan clutch doesnt lock up a lot more then the std duty clutch does like a severe duty clutch does. The small inc in fan rpm at idle from a hd clutch is very helpfull & not that noticeable or annoying. But a severe duty clutch would cool like heck but it would also drive you nuts with fan noise and kills fuel mileage too because it locks up a lot more then the HD fan clutch does.
Also,move the trans cooler away from front of the rad becasue its blocking cool airflow and is also heating air before it hit the rads greatly reducing the rads ability to disapates heat in the complete area behind the ext tans cooler. Place the ext trans cooler eslewhere and use the small elec fan with t-stat they make for ext trans coolers.
They make all kinds/shapes of ext trans coolers these days to fit all sorts of apps esp frame huggers for hot rods so chk them out if needed.
Increase the idle rpm some too if posisble to get a few more fan rpm for better cooling at idle when in traffic too.
Are you running high enough octane fuel?
In summary,get a new HD fan clutch ,adv base timing if not already at 16-18 with perf cam,attach vac adv to full int vac all the time ,chk idle mix to ensure its rich enough,increase idle some if possible for more fan rpms at idle in traffic for more airflow thru rad,ensure enough octane for setup,and move ext trans cooler from front of rad .
Doing all those things i mentioned above should reduce your in traffic temps and likely your cruise temps too . also ensure your not overfillng the rad resulting in coolent puke post shutdown too.(coolent 2.5-3" below filler neck when cold).
Oh almost forgot,you Better be runnng a fan shroud too and if not get one because you need it eps in traffic .
BTW,moving to a HD fan clutch from the std duty fan clutch will likely be your best reduction of in traffic temps along with advancing base timing if its retarded /below 16-18 deg with perf cam . As i said a HD fan clutch has always dropped in traffic temps some when i have used them vs std duty fan clutch on a bbc . They also get the motor cooled down faster after leaving traffic and hitting the open road & bing back up to cruise speed again too.
Lastly,not having a vac adv for a sttreet motor with perf cam really hurt perf esp when it comes to in traffic temps and throttle respince comming off ilde not to mention better fuel mileage too. dist with no vac adv for for race only and are not really correct for street use .
The only time to not run vac adv on a street perf motor is when your runnig a very lrg cam with too little idle vacuum being not enough to keep the vac adv fully activated at idle to keep the idle steady/stable . Or maybe a boosted setup of some kind that just wont tollerate it for whatever the reason could be another reason not to run a avc adv but generally with proper tuning 7 proper octane lfl fuel for setup which is often an issue with todays reformulated 91-93 pump fuel a vac adv is a real benefit for a street perf motor esp at idle in traffic getting temp down some from the additonal timing it adds at idle in traffic.
See below for HD clutch that will fit your car/bbc with long pump used from 69 on up.
HAYDEN FAN CLUTCHES (FROM HAYDEN SITE)
2747 H/d
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IMPERIAL FAN CLUTCHES (FROM HAYDEN SITE)
215046 H/D
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TORQUE FLOW(AUTOZONE)
922747 H/D = 215045 IMPERIAL FAN CLUTCH (FROM HAYDEN SITE)
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NAPA
TEM271303 - H/D
Scott
