TKOPerformance wrote:

RTM wrote:

TKOPerformance wrote:

Ah yes, another $1,000, but it may be the best money you spend on the engine.  I'd view it as a $1,000 insurance policy that never expires.  Something goes wonky in one of those Pro Comp heads and it drops something into one of the cylinders that $1,000 is going to seem like a bargain. 

For the record the only thing left in the pro comp heads that are pro comp parts are the hardened seats.

But I agree the new victor jr heads would provide a good sense of sercurity. 

And the Chinese castings, which may well be the origin of all the problems.  Such castings became available for 6.0 PSD Fords around 2012.  They seemed a bargain that would save $700/head over a Ford reman head if your heads were cracked (a lot were).  Then is started; guys started having coolant leaks because the decks would warp, and all the rebuilders started putting a note on their websites that they would only use Ford castings.  There have been numerous reports of Chinese made parts failing due to bad metallurgy.  Considering that's where most of our scrap ends up the picture starts to come into focus.  Recycled metal is never going to be as good as virgin material due to impurities and lack of control over the exact composition of the alloy.  There's supposed to be a threshold for maximum recycled material used in a part because of this, and it seems a lot of the Chinese parts makers just throw that to the wind.
 

That may be so and I am in no way defending the pro comp brand but one can find many first hand accounts of these heads being run succesfully with better companents.

I have decided to buy the newer heads and will be doing so tomorrow morning.  It just happens to work out in my favor because I will be meeting the seller half way which is where I will be picking up a set of axles.  The axles are 31 spline axles for a 65/66 which I need and they are brand new for $200.  I will have an early xmas tomorrow morning.  lol

I listed my pro comp heads locally and I will see if I get any offers.  I am still looking into buying the guides for them because I can easily istall them.  May help sell the heads and the guides should only cost me about $80.  At that point I just may get the valve job done and then they would be ready to go for some one else.
 

I'd flip them to offset the cost of the new heads.  Go ahead with the guides, etc. and they can be sold as ready to run. 

Don't put shims under the springs.   Get the spring proper valve spring cups from a place like Alex's parts.  The future owners will thank you.

By contrast my AFR 185 Renegades were ready to bolt on right out of the box.  I had zero issue setting up the guideplates and rockers, and found the AFR style guideplates MUCH easier to get right that the 1 piece ones on Edelbrock and other heads.  I measured pushrod length and bought an off the shelf set of pushrods that produced a perfectly centered contact pattern on the valve stems on every valve.

BB, are you saying the valve angles were different valve to valve, or just different than stock?  If different valve to valve did they change consistently the farther away from center you got?  If that was the case I'm wondering if that's on purpose.  A standard 4 barrel intake is going to have different flow port to port, and I'm wondering if AFR changed valve angles to try and equalize flow. 
 

Bought the new heads yesterday and already have a buyer lined up for the pro comps.  I also picked up a new set of 31 splines for my 66.  Met both sellers at the same location.  Been trying to make it to Tampa for more than a month to buy those axles.

Looking good!

MS wrote:

Never seen headers like those. Are shock towers gone?

 
Yes, I have a Rod & Custom coil over front end. They even clear the your clutch cable. 

When I bought my project it had a 69 Boss 302 stuffed in it. Whoever did this torched the towers trying to get it to fit.  I bought the complete coil R&C kit for $1000, so I went that route.

Bullet Bob wrote:

TKOPerformance wrote:

BB, are you saying the valve angles were different valve to valve, or just different than stock?  If different valve to valve did they change consistently the farther away from center you got?  If that was the case I'm wondering if that's on purpose.  A standard 4 barrel intake is going to have different flow port to port, and I'm wondering if AFR changed valve angles to try and equalize flow. 
 

Sorry TKO for not responding to this...just found your question.
The angle differences I encountered appeared to be variation in the "IN/OUT" angle of the valve guide which caused the  top of the stems to be miss-aligned by some 40 to 50 thousandths.  Not major maybe but not precision either.  The problem it causes is that for a really high zoot engine you could not get all of the rollers perfectly centered on the valve stem without the use of custom length push rods at each valve.  The fix would be a major re machine job which just isn't justified for a street engine.  This seemed to be random, not something AFR designed in. 
Additionally, while the two-piece guide plates do make push rod/rocker/valve stem alignment easier, they have a pronounced "roll" into the rocker stud hole due to the stamping process.  This roll provides an uneven surface for the rocker stud flange to seat against which causes the studs to go off toward Jones's.  I cured most of this issue by using a grade 8 washer under each stud.
These two issues coupled with the varying stem height made proper set up a PIA that I don't thing should be in the more expensive heads on the market.  JMO
As I said, I discussed these problems with an AFR front yapper at SEMA and he confirmed that I was not alone with my concerns and complaints.

BB1

So if I'm understanding you correctly you're saying the valve guides varied either closer to or farther from the center line of the engine?  I'd agree 40-50 thousandths is significant.  I'd also agree that for what AFRs cost that's unacceptable, as is being told "yeah, we know about it but basically aren't going to fix it and don't really care."  I wonder if my lack of issue here has to do with the Renegade heads being machined better?  Supposedly all this stuff is done on 5 axis machines so I'm frankly shocked that there would be that much variation in anything they produce. 

I wonder if Edelbrock would let that dimensional discrepancy pass quality control.

BB, I finally got a chance to talk to my buddy that works on CAD/CAM CNC machines and what he said is that the variance you are seeing is entirely possible if they are boring the holes as opposed to milling them, and if the drill bit is ground incorrectly for the material and/or they are using too fast a feed rate.  Basically its the result of bit wander,  He said basically ramrodding the holes for the guides could easily result in the variance you are seeing.  He said if it were him he would bore pilot holes and then create the guide holes with an endmill.  That way if the pilot hole was off it wouldn't matter because the finished guide hole would be perfect. 

NP, I enjoy learning about this stuff.

Maybe ignorance-is-bliss in my situation. (I just took'em outta da box and screwed 'em down!)
Windsor jr. iron heads.......bought 'em over 20 years ago from good-old P.A.W. speed equipment.
Maybe its because their arn heads..........who-nose?
Granted......they aren't the "high-zoot" max power  double-flipped drop-down gotta have'em  high performance Lumi-yum heads butt they do breath better than the stockers.
Seriously.......(IF that's possible!)...ya think the "issues" with  Pro Comp and others is BECAUSE they're Alum.?!
I wonder..............
6sally6