djcwardog

I spent the morning installing some gently-used Hooker Super Comp Ceramics (1 7/8" tubes) and got the left side done. I'll do the right side in a week or two. Interesting to drive the car - only from the base shop to my house - with headers on the left and stock on the right. I hope to see all that extra torque!

73 LS-4

gently-used Hooker Super Comp Ceramics If you only knew


Pat Kunz

djcwardog

I had a few free hours yesterday afternoon so I installed my L-36 intake and installed the Pertronix II kit on my stock distributor. I guess it is good that I am not running the stock intake and EGR system anymore. Let me tell you, the engine had soot in all the intake passages and the intake valves had lots of build up on the stems. I cleaned off what I could - and opened up the right-rear water passage which was closed off with scale. Maybe that will help the run hot issues this summer. I looked at the cam sitting down there and it had minor wear marks on the lobes... but I'll wait to replace it for when I rebuild. I had an oil leak at the rear of the old manifold and that is solved with the new install. I want to incrementally do these things and see how the car feels.

Anyway some issues after driving the car:

After installing the intake, I get a flat spot transitioning from idle to off-idle. Once I get the revs up, no worries. This did not happen with the left-side header on and the stock manifold. I did check timing and set it same as before - no dwell to adjust now though. I have yet to adjust the idle mixture screws, though I did adjust the idle RPM's yesterday. Also, Lars recommended 75 jets once I install the headers. I am running 74's based on his recommendation for the stock exhaust system. Perhaps a size or two up will eliminate the flat spot? I have 75, 76 and 77 jets on hand.

I am having fun getting the choke linkage set up. Seems that the 1968 rod and stove I got from Dr Rebuild will work, except that the retaining clip on the rod interferes with the arm on the carb. Perhaps I can remove some material on the top of the clip so that it doesn't bind... Anybody else running a 1968 L-36 on a 1973 Vette with a Rochester carb who can tell me what they set up for the choke? The 1973 choke rod doesn't work - the stove is offset out to the right side more than on the 1973 manifold.

I'll tweak this further today after I get home from the Base Garage and install the right-side (easier?) header today.

Thanks!

DJC

djcwardog

Slow and steady did the trick - I got the right side in. Of course, the a/c compressor had to move to do the bolts. The idler arm gave me some concern - it was blocking the last bit of snug-up for the header. I loosened its two bolts and tightened down the header bolts. I didn't really want to pound a dent in the header so I just tightened down the idler arm after getting the header down tight. Will I hurt anything by having the idler arm rub against the header? I can always loosen the idler arm again and pound a dent in the header...

corvettecris

Make sure you keep those hookers really clean. I had the ceramic coated ones, and they rusted up really badly. This was a few years ago, so maybe they have improved their ceramic formula by now.

djcwardog

...by auto-placing a small dent in the header tube right where it was touching the arm. Likely as a result of idling - and in going gonzo on the gas pedal out on I-81! I just had a local Meineke shop fab up new front pipes, weld in an 02 sensor bung on each side right behind the collectors and add a balance pipe right behind the bungs and before the stock junction with the rear pipes. I plan to buy a fuel-air ratio meter and use it to tune the engine. I am going to use this paragraph in a new post specifically to give good marks to the local shop.

73 LS-4

DJC,

Glad to see your making progress. As far as the divorced choke rod setup, all I can say is good luck. I've gotten mine pretty good but still not perfect, using a coat hanger bent to shape for the rod (yea I know bubba but it works). You may try going back to your stock jetting of 77/48 on the primaries as a starting point.


Pat Kunz

djcwardog

I drove over to NAPA and they let me rummage through their small carb parts. I found a better clip to hold my divorced choke rod onto the carb than what I got from a Corvette vendor. I bent the rod to rest at bottom stroke and touch the underside of the notch on the choke lever. Then I used a friction-fit washer (you know - the kind where the hole is punched out and the flanges grab onto the rod once it is pressed over the rod tip) and now my choke holds tightly closed at startup and then opens fully within a couple minutes. Now for the air/fuel ratio gauge and rejetting...

djcwardog

After recent engine work I thought I should update this old post as well - see sig for the updated parts... Finalizing carb tuning - again... This carb uses an electric choke so I ran a hot 12v wire to it and put all these divorced choke parts in my parts collection.