66 Riv GS 425, slightly hotter cam (Isky HP-2), dual edelbrock performers Ok, I got the spare heads cleaned and are due to be magnafluxed. The valve seats look fair and should not take much cut to make them like new. They look so nice that I wonder if a multi angle job is even necessary. I have spoken with the local machine/speed shop about opening up the area under the exhaust valves and he was very honest about possible damage and not having any experience with this style head. I need some real life experienced person to give me the lowdown on making these baby's breathe better. I have new exhaust valves and wonder if there is any work to be done to these. The intake side looks very nice and I don't anticipate doing much (if any) work to those. Any and all advice would be greatly appreciated. Also, if anyone is interested I will take pictures of the work as it progresses. Thanx, Lou
Intertech Research ~ Nailhead Head Porting Specialist ~ Ed Mosler - 1489 Thesta Street - Fresno, CA 93703 (559) 486-8202
Hi Lou, Glad to hear you are making progress with your Rivie...The reason I post is to relay info from the Nailhead group at Yahoo. Extensive dyno testing was done recently. Stock 2x4 manifold, offy, edelbrock B262, various cams,various CFM carbs, different combos, porting by the foremost gurus...in short, the WORKS! Didn't add up to a big difference. Edelbrock manifold was the winner...but not worth the $800 you need to spend for one at ebay. As you can see, there's nay room for valve enlargement. Messing with the intake ports ( yes, around the stems) creates a bad case of turbulence. In short, the factory did one hell of a job! These are grunt motors that can beat an elephant at arm wrestling and unless you want to spend a couple thousand in shipping for a few more horsies...save your hard earned money for a better paint job. Now, I may of caused __IT to hit the fan and get blasted for this, and I'm not trying to hit anybody in the wallet, but in this man's opinion, that's just the way it is! Rivies are never going to be the fastest cars at the track. Damn fast, YES, but not the fastest. These engines were designed to pull BIG, HEAVY, FULL SIZE BUICKS with ample power. And THAT they do Extremely well. It's like lining up a Corvette against a Peterbilt! Lou, you will get more performance with the installation of the idle detent switch and stator switch we talked about that with all the head work that can be dreamed up. I'm just letting you know my thoughts...Steve
Hi Steve, I forgot to tell you in my last mail that the detent switch is there. It is on the inner side of the throttle arm not on the outside like yours is. It is tucked away so neat that I had to dive over the radiator to see it. I switched the ignition on to run and heard the trans click then worked the pedal and heard the trans click coming off the bottom pedal stop. I guess all the electronics work but still feel like its missing something. The car was rebuilt down south before I bought it, I wonder if they did something to the trans/converter then. I have not found a mechanic that understands this setup yet. If I bought you a ticket could you spare a day or two?????. Back to my reply to all, it looks like relieving the area under the exhaust seat is the biggest attack area but this will all be done with a die grinder as it looks thin on the side. A funny side note, I have a friend (big chevy nut) helping me and we cooked the spare heads where he works and I just went and picked these up. He said to me, I think sombody has polished your chambers already. I was looking at the guides and wonder how much can be taken off in the runner paths. The stock guides only had seals on the intakes, whats up with that?
There was a post about nailhead head porting a few months back, in the nailhead section. Read that and then make your choices.
Lou, Good...you have the idele detent and it's working. Let's check that it is set up right: Get the car FULLY warmed up. Choke all the way open, fast idle screw all the way past the last step. Now, you pull back (towards the firewall) EVER SO SLIGHTLY with the topmost, rearmost portion of the throttle rod bracket(the steel portion that the switch is mounted on). With this slight touch, the switch/button should disengage. This is before there is any rise in RPM"S. If not, adjust by turning the switch body with loosened screws.Let me know what happens. Once this is cleared up we'll move onto the downshift switch. This car should burn enoughrubber to make the goodyear stockholders jump for joy! Also, I have a friend in CA that makes a living tuning 63-65 Rivies The 65's are the same as the '66's...DualQuads are his specialty...He gives phone consultations and a real nice guy to boot...if we need him I'll shoot you the number. Steve
