The key operative words are: "i'm am very optimistic that this will fix my issue".......if it fixes the issue...GREAT.......if it doesn't fix your issue .....what's your plan B?.......Just curious.....
So, it knocks with anything less than 91 octane, but you don’t know where your timing is set? There’s a hint right there. Instead of trying to bandaid your way through this, start with the basics. Make sure your timing is set right, make sure your hood to radiator support seal is in place, make sure your hood to cowl seal is in place, and the lower radiator support to splash pan seal, if your car has one. If your temp goes up sitting at a light, and goes down while driving, it’s an airflow issue. Funnel that air through the radiator, use a clutch fan and a proper conical shaped shroud, and make sure the seals are in place. An aluminum radiator may help in letting more air through, but it needs to be funneled through the radiator, and drawn through with a proper fan and shroud. And check that timing, something is not right there.
If it doesn’t fix the issue , then I’ll keep at it till I figure it out. This would actually be plan D. Shroud was plan A, water pump was plan B and the radiator is plan C. Radiator came today but it will be the weekend before I get it installed.
I checked the timing a few weeks ago. All good there. Also, the radiator that is coming off the 68 is going on a different car so there was plan there……
What is the timing? Initial and total.
What is the pitch diameter of the water pump sheave? Remember the more rpms of the pump will result in higher circulated VELOCITY and VOLUME of coolant promoting better heat exchange in both block, heads and radiator as more heat will be transfered. Do not believe in the belief that the coolant must be slow thru the radiator to relief the heat...that's BS....High VELOCITY is the key to heat transfer. Shop for a sheave with smaller PD but the same bolt circle as your existing sheave....
12 initial and I cannot remember total. I believe I’ve got it written down in the shop. My neighbor, who is more mechanically inclined than I am checked with both timing light and vacuum pressure guage.
To figure pitch diameter
Bob, would fan clutch part 2947 fall into the category you are talking about regarding the fan clutch? Hayden and Murray use that part number. I was looking at that clutch as it has the less than 3” depth option which the 2747 and others don’t seem to have. Also looking up the 2806070 part number a few places note it’s a clutch for a non AC car. Mine has vintage air. Does that matter? I will go through my pulley dimensions and get that figured out (thanks for the diagram!). I do have the 7 blade, 18-1/2 fan so I’m good there.
Thanks for the offer. I had to return a 2747 clutch that I already had as it’s now too thick for the radiator I have.
The Jag clutch is 2765 it's ok, the 2947 is shorter still and drives the fan a higher percentage of the time..
The # 2806070 clutch is TORQUE DRIVE unit installed on MOPAR'S HP engines.....it will not slip at low rpms. It will work on a non a/c car just fine, but may be a little noisier at low speed. As a repro unit, it's expensive..~ $300. Every one balks at the repro cost; price for the Hayden unit at ~ $50. By using aftermarket radiators, space to accomodate the correct clutch becomes critical, hence the use of the HAYDEN clutch, which does not perform adequately. As I see it, your easiest solution is drive the water pump faster for a higher fluid flow (velocity). A suggested sheave for the water pump is # 2946716 and a suggested fan is # 2863216 (a HEMI 7 aluminum blade steep pitch blade shape at 18 1/2" diameter). You can find both on line and thru MOPAR only part suppliers.
Air flow is measured by CFM (Cubic Feet / Minute) x SP (Static Pressure) at a given density. What is the AREA of the radiator you're holding the dollar bill against......that proves nothing except air is being pulled thru.......it doesn't show HOW MUCH AIR (CFM) is being moved or the pressure or the engine rpm.....
