Thats darn impressive. 40* is a heck of alot of timing for a smallblock did it run faster with the timing that far up?

Even more impressive given the fact that grooves are supposed to reduce the need to total timing.

i notice in all of the picture you have polished the combustion chambers, when i was porting my heads i was going to do this, but i was advised by a local engine builder that it would have been a huge waste of my time. the engine is just a stock 350 crate engine, hencho en Mexico, with an older set of heads and a small cam, i don't have the card handy but it was a "1500-4500" crane energizer. compression probably no higher than 8.5 or 9 to 1. im wondering now if i should have taken the time to polish the chambers.
Have you tried the grooves with any type of forced induction application, turbo for instance?

leldai73,
When I do and all out port job I work the chamber to unshroud the valves and
carefully blend the top of the valve job into the chamber. The primary objective
is to enhance flow around the valve. A secondary benefit it to eliminate heat
risers that may lead to pre-ignition.

I did two sets of grooved heads for engines running roots style blowers. The
engines ran great. I did one set for a heads up style twin turbo car, I haven't
heard results from the owner.

He (automotive breath) said he was able to run the timing up to 40* without knock. Didn't say this was the timing point were max power was made. The grooves probabily enhance the swirl just before the plug fires, so much that the engine becomes tolerant of extra ignition advance. (detonation resistant.)
Even thou this extra is not nessessary for max power.
Have you tried this yourself? You need to open your mind a bit. I think that on engines that are on the edge for the fuel used as far as compression ratio is concerned, these grooves have some merit. Am building such and engine now and will be evaluating the grooves myself.

F-Bird, the claims of these grooves are, and have been, always based on heresay. Even the small amount of actual hard data that has ever been posted on this has shown very, very little if any benefit.

Open my mind??????????????????? We test many, many, many things via the cam doctor, flow bench computer software and dyno on a weekly basis. Do we have any plans to test grooves? Nope. No reason based on the teeny bit of data so far to hack into a perfectly good set of cylinder heads.

F-Bird, Your are right. This engine belongs to a very good friend, he loaned it
to his son to make a big race. Not having experience with the angled parallel
groves, I had concerns that the son would hurt the engine running it on 93
octane with the compression up that high. We had three time trials before
eliminations on the Friday night race. Before the second pass I set the timing
at 40 with a new set of plugs to check for detonation. I felt good with no
detonation at 40 degrees, we put it at a safe 36 for eliminations. We didn't
have time to tune it properly.

Normally with this combination I get concerned about detonation above
10.5:1 compression, I was thrilled to see this one run on 93. I don't consider
this "proof", I do consider it impressive.

64 cc chamber ported Edelbrock RPM heads
Flat top 383 CI
COMPRESSION RATIO 11:1
Isky flat tappet; 258 degrees at 0.050"; 0.550" lift

I'm not so conservative with my own stuff. My current build is a flat top
355 with 50 cc chamber iron topline heads . The camshaft is the same Isky
flat tappet grind. Using an new concept I will be attempting to push the
limits of the 23 degree SBC engine. The static compression will be above
12:1. Initial tuning will be done with 100 octane eventually switching to 93.

I was looking at something on Crane's website and came across this tidbit. Very interesting.

[I]Flame Speed -
Flame speed or burn time is the time in milliseconds during which 10% to 90% of the fuel is burned. The flame speed is a function of fuel, chemistry, and your combustion chamber configuration (flat top, dome piston/angle milled heads, etc.). Your ignition timing can also tell you the efficiency of your combustion chamber due to the amount of time it takes to burn. Hence, less timing equals a higher efficiency in your combustion chamber and more timing would equal a less efficient combustion chamber. Most enthusiasts believe that more ignition timing makes more power but, in fact, a higher efficiency combustion chamber along with running less timing will increase power because of the quicker burn time. The actual component make-up of a racing fuel will also influence the burn time whether it?s a high-octane fuel or not. Racing fuels usually have the flame speed adjusted based on the intended application (i.e. blower, nitrous, engine RPM, compression, etc.).

JMark,
Thanks for the quote. Here's a link to some interesting information on
squish action and flame speed. This is written about two stroke engines but
interesting non the less.

squish action

After reading all 14 pages of one of these threads I had to join this forum so I could jump into the fray. I'm in the process of rebuilding a Jeep Cherokee Sport 4.0l for my daughter and son-in-law to use as a grandkid hauler. The Camry doesn't have room for two car seats, luggage and camping gear. It doesn't even have room for the luggage. I've been surfing the web looking for MPG improvements to bring the Jeep somewhat closer to the MPG they're used to getting with the Toyota. "Good luck"! You're saying. I can hear it from here. My searching has yielded ideas such as less restrictive exhaust, less restrictive air cleaner, bored throttle body, throttle body spacer, 98 and later intake manifold and then I came across this: grooved heads. I read the original story in Popular Science years ago and find it interesting to read what AB has to say. I'm going to groove the head of the L6 and see what happens. I've been a "thinks out of the box" person all of my life. My cousins called me the Mad Scientist when we were growing up back on the farm where Saturday night was congregating in the shop and listening to American Top 40 on the radio. We had a shop with overhead cranes in all four bays, a dedicated welding bay and a dedicated wash/paint bay. We had hot rods too.
But what I'm getting at is the nay sayers. "I'm Mr. So full of Myself that this will never work because I say it will never work." "I've been Nay Saying this concept for years and I dynotest a thousand engines a week, but I'll never try this because I've already declared it doesn't work" I've listened to this kind of bull all my life! My Appreciation to AB for continuing on despite the yapping ankle biters continously at his heals. I'm always amazed at people who proport to be so wise and yet don't know the difference between "you're" and "your". It goes like this: You're (you are) so full of yourself that you're going to get top heavy from your (posessive - it belongs to you) big head. The same thing goes with they're and there. They're (they are) always out there (a place or location), those nay sayers. It just makes them feel important to tell you it will never work. I know from experience having had to listen to it myself. Language only matters when you have something to say. BTW - "Too" means more than enough. not "to".
I'm anxious to see what happens with the Jeep. I plan on implementing all of the tricks at once. I won't have a baseline because the engine is in pieces as I buy the Jeep. $200 for new tires and wheels and a Jeep comes with them! I do wonder about varing the mixture and timing on the OBDI engine to get maximum benefit from the head.
Well, you pioneers, keep on keeping on. You naysayers, keep those yappy teeth sharp! -Scott

to dyno 1000 engines a week you would have to dyno 17.9 engines per hour.

that calculation is based on working 8 hours per day 7 days a week.

Very interesting I'll be asking questions later
Shane

Boy,talk about being close-minded!If you have all this equipment handy and you test weekly,why are you AFRAID to find out this works? how did you know Cam Doctor works for YOU? YOU TESTED IT!!!!! How did you know a flow bench works??? YOU TESTED IT!!! Do you need ALOT of data to go ahead and test grooves? Are you waiting to be one of the last ones to test this,or test this for yourself and draw your own conclusion? TEST THEM AND THEN YOU CAN TRULY SAY IF THEY DON'T WORK OR NOT. If i had all this "equipment" at my disposal, i'd test everything that people are just starting to do,.

Good luck with your Jeep