PSMCDR...new "tech"

[Chevy454]

Just wanted to let everyone know that we have made a suggestion to the folks at the Pure Stock Drags. Our suggestion is this. Have each racer wanting to run in certified stock sign up in advance, stating that they would agree to a full POST RACE TECH on their car and at that time, prove the legality of any parts in question. After a car's last pass, it would precede directly to the impound/tech area. If a car does not pass this post race tech, then all times, media coverage, etc. associated with this car is moved to the regular class. If some one refuses tech, all times, media coverage, etc is destroyed and the racer is banned from future events. We feel that a post race tech would be much simpler, as the cars could be put back together at home, rather then at the track. It is not the teardown that people dread, its the thought of getting the car back together in a timely manner, plus, getting everything set just right to run the times the car is capable of running. A post race tech would allow cars to be dialed in before they reach the track. This would make for more accurate bench mark times. Also, a post race tech would allow the officials and the media as much time as needed to go over the cars. Tom

[Edited by sYc (10-27-2000 at 05:48 PM).]

[COPO]

Great suggestion!

[Rowdy Rat]

Tom,

That seems to be the best solution to the teardown issue. I hope that Dan and Bob see it that way as well.

bbdon,

The 3904392 (1967) and 3919842 (1968-69) closed chamber aluminum heads did indeed use a 1.84 inch diameter exhaust valve and were the only big block Chevrolet heads ever to use this valve size. I don't know why Colvin chose to use 1.72 in his book, but it isn't correct. The 3946074 head used on the ZL-1 and second design L-88 engines in 1969 were the first to use the 1.88 exhaust valve.

There may have been an even earlier aluminum head used VERY early in the 1967 model year, casting number 3904387, but I have yet to gather any details on this head. Anyone have any information on this particular casting?

Regards,

Stan

[Ray Morrison]

Stan,
I do not have any casting numbers, but looked at production numbers on the 67 L-88 Corvette, and find both the L-88 & L-89 options with production beginning in February, 1967. According to this information, 20 L-88's & 16 L-89's were built with these options? I know this doesn't fully answer your question, but this might be of help?

Concerning the exhaust valve size on the 842 aluminium heads, my reference lists them with 1.84 exhaust, also? These are Closed Chamber Aluminum Heads with 106.8 CC's. While looking for information on the 842 heads, I did come across another aluminum head casting number with no application, I did not know existed, that being 838. Is this the L-89 head? Does anyone have the specs. on these?

[Chevy454]

Well, while I was looking up blueprint info over at NHRA.com ( http://www.nhra.com/tech_specs/engine/ ), I looked at what they had listed for the L-78/L-89 option. They show 2 aluminum heads, casting #s 842 & 401, in 1968 & 1969, their valve sizes are 2.195/1.845, and they were available only on the Camaro. Now, I know this shouldn't be taken as "the gospel truth", but that is what the NHRA shows.

[sYc]

The Pure Stock Drag Racing group has decided to stick with their original plan of a prerace tech. I tried to explain that I thought it would be much easier/safer if the cars could be assembled at home, after a post race tech, but to no avail. The cars will be teched the day before the event. Tom

[Chevy454]

Also, the date for the PSMCDR has been pushed back a week, from the 6th to the 13th.

Also, I have heard rumors that there will be a '70 COPO Nova that will also be participating in the "certified stock" tech...