As efficient in cooling as heads designed for reverse flow to begin with?
I know they move more air but my only concern with them is whether or not they work as well on the street. I'm in savannah and periodically I drive the camaro back home to Ft. Worth. I don't want to put anything on the car that won't be completely streetable.

 

AFR's LT1 castings aren't as good as GM's LT1 stuff in terms of cooling. If that helps. Basically it comes down to the design of the heads in that area. The TFS castings are much better than the AFR's from what I have seen.

Bret

 

Thanks Bret but what about a set of standard sbc 23* head you could convert to reverse cooling for me? Say like some All pro S heads.

 

Just curious why you'd want to convert a regular set of 23 degree heads? Why not either go with some LT4 AFR's? If you're going to go through the trouble of converting an SBC set why not do something like an 18 degree head?

 

It's the company that makes the heads that's going to be the biggest difference here.

GM by far does the best on water passages in cylinder heads, LT1 or otherwise, while AFR does about the worst job.

The LT1 dedicated castings from TFS are pretty good and All Pro does a very good job in this deparment as well.

Has nothing to do if they are LT1 or not, has to do with WHO makes them.

I honestly think that one of the best ways to get a bad *** 23* casting is to convert over a set of SBC heads to a LT1 and have a CNC program put into them. All Pro and Brodix have some awesome CNC programs for their 23* stuff that would save you time in terms of getting the heads and getting the results you are looking for.

Bret

 

When I had some converted Brodix heads on my engine, the cooling aspect was never a problem. I had problems elsewhere, but the cooling was fine. I use a 180 degree thermostat and never saw any cooling issues.

 

Really have to research this well and those reading this who think it might be a good idea look into the flow numbers. There are some 23degree gen1 heads that flow better than the stock LT1 heads but there are even aftermarket ones that do not flow as well as them. I am sure you two realize that just thought it was noteworthy for the less experianced.
To make this a little clearer what CFM would you say you needed to be looking for in order to make a gen1 conversion worthwhile, I know I have seen numbers around 300cfm for LTX castings so where would you place the line between when LTX heads will be cheaper and simpler and good Gen1s would be better?

 

Obviously I wouldn't say to conver over a junk 23* head. The Brodix and All Pro heads are both 300+cfm, hell they can move 370cfm. We are talking something to replace a big AFR or AFR 215RR would be the way to go.

Bret

 

Exactly, I want a set of All Pro 220 instead of the AFR 215RR. I just want to know if the car isn't going to run as cool. Or if there is another problem in running converted sbc heads I don't know about.

 

I would rather have those too!

Actually it has more to do with the water passage design... from what I have seen the All Pros have a better coolant passage than any AFR I have seen.

Bret

 

Gotcha

 

Other variables removed, the reverse cooling is a more efficient means of cooling the heads. This, even before the flow tweaking with the head gasket, was undertaken. Familiarizing oneself with the flow path thru the engine will reveal why RC is superior. Actually, Yunick and Moroso found this out in the 70s. Does that imply you will experience overheating problems? A lot of engines were cooled (in performance environments) satisfactorily before reverse cooling came along.

 

I could have added that 'efficiency' can have a different meaning to different people.

On one hand it can imply extracting the most heat from the engine (heads). However, that is a double edged sword of sorts. The more heat that is removed from an internal combustion engine, the less torque/power will be transferred to the flywheel. IOW, the engine is now less effiecient due to a more efficient cooling system. The reversed flow cooling is more efficient, in that regards, compared to the traditional flow system.

I consider a more appropriate means of determining an 'efficient' cooling system, is how 'uniform' the head temp is, after necessary heat is removed from the heads. IOW, are any hot spots around chambers/valves remaining, when other areas (near where the coolant temp gauge sender is located, for instance) are at a more desireable/acceptable temp reading? The reverse flow cooling system DOES help in regard to this issue as well, but, and as Bret (not Brett or Brent), again, as Bret noted above, utilizing castings with superior coolant passages/jackets in crtitcal areas such as around exhaust valves and chambers, can be considered MORE effective in THIS regards. Mods common to race engines, also provide a means of improving the effectiveness of the cooling system around the critical areas mentioned above.

Ideally, I personally prefer a cooling system that removes the minimum heat necessary, without leaving overly heated spots in localized areas, in the coolant's wake.

 

Bret, Care to elaborate on the problems w/ AFR's cooling passages?

Also, maybe I'm missing something, but I don't see how a traditional SBC head with similar runner sizes to an LT1/4 head is going to flow 370 cfm. My understanding is that the LT1 has basically identical block design as far as cam location, lifter bores, and pushrod location, so how can a SBC head flow that much more than say a AFR 220 or AFR 227 or any other large runner head without being much larger in runner size since you still run into the same pushrod pinch points, etc?