SK.LT1

Does anyone have any experience with the A.F.R. heads on an LT-1? I have a 96 LT-1 auto and am considering upgrading it with a Comp Cams cam,1.6 r.r.,and A.F.R. heads.(they have 180 runners,2.02/1.60 valves).

fredk

I just got mine put on. I got them from TPIS ported and polished for $1850. which is cheaper that anywhere else that I could find. I won't be up and running for a while yet as it is a home do it yourself project which I am not rushing. It is a long winter up here anyway.

robs87vette

I foud the AFR heads to be about $300 cheaper Than TPIS even w/the $150 valve spring upgrade by ordering them directly from AFR.

Nathan Plemons

You'd have to compare their cost and their flow numbers with ported stock heads. Personally I haven't been particularly impressed with AFR's quality. Apparently their QC is a little hit or miss depending on what day of the week it is.

When you're talking about stock LT1 heads it's also very rarely beneficial to go with 2.02 / 1.60 valves over the more easily installed 2.00 / 1.56 valves. You gain a little bit of upper lift flow with them but you give up a lot in the midrange which tends to result in a decreased area under the curve and thus less power. AFR's could be designed slightly differently but I'd have to see the flow numbers first.

fredk

Intake 400 - 247 Exhaust 400 - 171
500 - 272 500 - 185
600 - 275 600 - 196

Nathan Plemons

FWIW I got the AFR flow numbers from their website and plotted them against stock and against my TEA CNC ported stock heads with 2.00/1.56 valves.




Intake is smoother in the mid range, exhaust is quite a bit worse above .500.

All told the numbers don't look terrible by any means, they should make really good power. I'd have to compare the cost of the AFR's vs good ported stock heads before I could make a decision.

d48mclain

Don't trust the flow numbers on AFR's web site as rarely will they match the heads you purchase. Also..... you must be quoting exhaust flow on your LT1 heads using a pipe to flow them. AFR's will always outflow stock casting on the exhaust and that includes LT4's. No big whoop as the power is on the intake side.

Not a big fan of AFR.... owned a set of 227's and the heads ran 10-15 degrees hotter and had oil pooling issues. It's my understanding AFR has gotten a fair amount of criticism regarding the oil pooling issue and has corrected it.

Also….. they should be coming out with redesigned heads here pretty soon as they are suppose to be revamping their entire line. All AFR LTx heads are just their regular heads converted to reverse cooling.

I'd wait for the improved ones if I were to buy AFR plus Lloyd Elliott is getting 290 cfm flow from LT1 castings and for the money, that’s pretty damn hard to beat. An aftermarket casting will flow more when ported, but unless your going for full kill……I have the stock casting ported.

Nathan Plemons

Yes my exhaust ports were flowed with an 1 3/4" pipe but that is also what AFR uses as is clearly displayed on their website. Personally I'm not a huge AFR fan either but if they are not completely full of crap on their numbers the heads should still make good power. I can't completely agree on the power being on the intake side. Yes you have to get the air and fuel in but you also have to get it out. A head with a good intake and terrible exhaust won't perform as good as a head with good intake and exhaust.

Red Tornado

what is the story with this oil pooling issue? is this symptom indicated by a blue cloud of smoke on startup, after sitting for awhile? i'm not talking worn valve seals or guides, i mean brand new AFR heads.......

scorp508

One of my friends had this problem on his 383ci L98 w/brandnew AFR heads. The oil was filling the valve covers up so much that the oilpan would run dry. They ended up having to enlarge the oil return passages, which isn't that easy with the water jacket right there.

Red Tornado

sounds like its hit or miss. luckily i haven't had any problems with the AFR heads. i bought mine from TPIS, its their AFR/TPIS head. i'll have to check on the oil return passages, whether TPIS had AFR modify them or not. i know the combustion chambers and runners are all based on TPIS' CNC program.

thanks for the info.

Nathan Plemons

I would imagine that this would have to be a symptom. Even the best oil seals and guides have to allow SOME oil through for lubrication. Since this stuff is normally lubricated by a splash oiling system it's not a problem, but if it were to be immersed in a pool of oil then more oil would be allowed seep through the seals.

Steve85

Nathan,
If I'm not mistaken, you have a really good rapport with the TEA guys so I wanted to ask you if TEA has tested AFR heads "out of the box" and what the results were compared to advertised #'s.

If you feel answering this here will put you or TEA in a bad position, feel free of to respond PM or just maybe hint at the results or plead the 5th.

I have their 210's and will get them flow tested as part of my rebuild, I just wanted to be able to compare them to other non-AFR flow tests. I am not trying to stir anything up, this info is solely for personal use to make sure I have accurate results before deciding to/not to spend money in that area.

Thanks

Nathan Plemons

TEA was bought out my Summit Racing and moved to Ohio.

When I actually worked for TEA I had a set of AFR heads come across my bench and I was absolutely not impressed. First they weighed half again what stock heads weigh and the casting quality was poor. Imagine the "front" or "rear" of the head when it's bolted on the engine, one of these surfaces still had casting flash on it. Why? because there wasn't enough material in the mold and thus when the rest of the surface was machined flat there was a valley that didn't get cut. It seriously looked like complete ****. Functionally it wouldn't have affected a thing but for the cost of the heads I felt that would have been competely unacceptable.

I know at the time I made some mention of what I found on the forum and somehow that got back to AFR and they were royally pissed. The owner of TEA talked to me, he wasn't really mad, he just pointed out that I needed to be careful about what I say. Well I don't work there anymore and I still believe what I believed then. IF YOU DON'T WANT SOMEBODY TO TALK BAD ABOUT YOUR PRODUCT, DON'T GIVE THEM ANYTHING TO TALK BAD ABOUT! I am not going to lie about your product just to make you look good!

Unfortunately I can't remember at all what even happened with that head, if it went across our flow bench, etc. All I know is that I wasn't impressed with AFR's product or their company.

Instead of reacting in an "oh ****, how did that defective product leave here" manner they said "well you don't need to tell people about or defective products." It could have been a one time fluke but I'll never buy AFR because of it.

Steve85

I will to get a pic or two of the spring pocket depth of a set of Brodix Track 1's I have in the garage. The depth of the AFR pockets is MUCH deeper and there is nowhere for the oil to go. This causes puddling right at the valve seal. Now, I have not seen how much oil puddles there while running or remains there right after it has been shut off, but based on the shape, there is more oil there than on comparable heads.

Steve85

I remember that now! It started sounding real familiar about halfway through.

Red Tornado

hmmm, interesting......and thanks for your effort in advance. i sent an email to TPIS on this issue, but i doubt if they will admit anything.

at any rate, in my case i've had no symptoms, mine's a daily driver and i've put about 7,000 miles on them so far. again, mine were not purchased direct from AFR or an AFR distributor. these are the "hybrid" AFR/TPIS heads. i may be mixing apples and oranges here, i have no idea.

Steve85

In picture 1, (Brodix Track 1)notice how the side of the valve pocket toward the exhaust side of the head has no ridge and the rocker side does. The lack of a ridge on the exhaust side, or the low side when mounted allows the oil to drain away from the pocket.



In pic 2, look at the guide in the center of the 3, and note the relation of the depth of the rocker side of the pocket to the top of the guide. It comes very close to the top, and the bottom of the valve seal sits below it. Now, the problem with the AFR head is that the pocket is that deep nearly all the way around, giving the oil little room to escape. The exhaust side (low side) on an AFR head is ALSO that deep, hence, puddling around the valve seal.

EDIT: Go to AFR's site and look at the pic of the SBC 210 head. Look at the spring closest to you very closely and see how much of the bottom of it on the exhaust side of the head is buried in the pocket. That one side is open to the drain, the other end of the head is as well, but there are 14 more valves in the middle that don't have that luxury.



This is a pic of a set of Bowtie 18* heads done by Keith Dorton. Note how little area there is for oil to puddle around the spring/seal, even on the rocker side. You can even see divots around the bolt hole to allow any puddling to occur away from the valve. These heads are designed for a race car that spends hours at max RPM where oil control is a more important factor than a street head.



We do have to consider that the heads do not sit level on the engine, but, it is still clear that there is more oil in the spring pocket of an AFR head than virtually any other head. And, there is no channel along the exhaust side of the head from drain hole to drain hole. Oil is getting stuck up in the valve cover in an AFR head more than others.

Red Tornado

great pics, shows it very well, thanks.

how in the world can tens of thousands upon thousands of these heads be out there, and not the same number of people lining up for a refund?

Steve85

Your welcome.

Being sold on the AFR brand probably has alot to do with it. When that occurs, people start making excuses for the company and further justifying their own decision. You say you have AFR heads and everybody (almost) instantly thinks, "the best". In this context, it's really no different than how we justify all the shortcomings of our C4's as ...."character"


They are great performers, but there is always room for improvement. Maybe in their new line this will be addressed. And, as I mentioned before, the head does not sit level and driving will splash things around quite a bit.

But you're right, there is a design "quirk" that seems to serve no purpose except increasing the chances that your valve seals will leak.