rsicard

Gentlemen: Thanks to all of you for your responses. The full length headers are REALLY expensive and just do not know if they will fit the 1971 Datsun 240Z with JTR engine mounts. Will have to call the supplier to find out the fitment of these headers and man are they expensive! I am planning to have the 240Z low to the ground wherein very little air gets underneath the car for good downforce.

I don't want to modify the steering shaft! Want to leave it stock. Just want Sanderson to get some of their headers and MEASURE and MAKE CERTAIN that dimensions published on their Internet Site are CORRECT! Not that much to ask. Otherwise I will fab the headers myself and hopefully with lesser restrictive bends or better FLOW. Don't want to modify that which I do not have to.

To get MAXIMUM performance out of a 383 that cost 10k+, 1 3/4" headers are needed. Sanderson would only offer 1 5/8" headers with 3" collector for 240Z. They also have 1 3/4" but WOULD NOT recommend them for the 240Z. Hard to get them to realistically measure against what they recommend for 240Z.

Still looking for 1 3/4" primary and 3" collector block hugger header manufacturer. Have talked with Sanderson but they INSIST on ONLY ONE header which has 1 5/8" primary tubes and 3" collector. I have a HIGH performance SBC 383 stroker and NEED 1 3/4" primary tubes in order to breath properly. If ANYONE has a lead on some GOOD headers that can be used with STOCK 1971 240Z steering shaft please chime in. Thanks.

Sure seems like putting 10 pounds into a 5 pound bag.

Gentlemen: AGAIN, if the timing chain with some wear could be seen through the timing cover one would see the slack in the chain just flapping around and causing the camshaft and distributor varying according to the slack in the timing chain. With a gear drive this situation is much reduced if not ELIMINATED. The cam events and distributor timing are MUCH MORE PRECISE. The whine on a quiet gear set is the byproduct.

Ryan, your the man! Thanks much for the measurement. Will look at rewarder headers.

Ryan: I also have the Subaru Power Steering Rack but have not installed it yet. The reason is I am concerned about feedback from the steering when racing. Yet at low speeds the manual steering effort goes way up. As for the headers, if you would please photo from the cylinder head to the outer most part of the primary tubes with tape measure and pass this measurement along. Have built a strong SBC 383 and want to get the most out of it. For your steering, please send some feedback as to how if feels at higher speeds. Thanks VERY MUCH for the photos.

Ryan: I also want to run 1 3/4 inch block hugger headers. Which ones did you use and do you have JTR engine mounts? Any interference from the steering shaft to the headers? Please advise. Thanks.

Lane: You just hammered out the technical questions by you answer. Will correspond with you via your Email address. Thanks VERY much.

Long240project: In looking at the second photo you attached it looks as though you fabbed your own engine mounts. From the second photo there looks to be a small tube welded horizontally fore and aft welded above the original Datsun engine mount. This would place the V8 forward of where the JTR engine mounts position the V8. This puts the headers into a more interference situation with the steering shaft. This may verify my assumption that the steering shaft threads it way through the header tubes. Are you going to use the Hooker Headers once your Datsun goes back together? If so I apologize for the wording to purchase same. Unless you know of a source that has these Hooker Headers, it appears that they are no longer available. Hope to hear from you soon.

Long240project: Thanks very much for your reply. Your car looks great. Very very nice color. Please give me a brief description of your engine mounts. Did you make the mounts? The Jags That Run (JTR) engine mounts push the SBC V8 back near the engine compartment/passenger firewall. This makes the most amount of space available for block hugger headers and a small amount of space between the block huggers and the steering shaft. I read the instructions for the Hooker Super Comps and it says to remove the steering shaft, install the headers and reinstall the steering shaft. This almost sounds that the steering shaft threads it way through tubes of the Hooker Headers. Is this true? After some discussion between you and I, and the discussion brings out the appropriate details of the Hooker Header installation, then I would pay shipping both ways from your place to mine and the reverse if needed. If the Hookers fit my 240Z with JTR engine mounts HERE, I am willing to pay you for the headers. Talked to Hooker and they said the headers are not made anymore. Talked with Summit Racing and they do not have these headers any more. The other option for headers is to go with the JTR headers.

long240project: I am interested in the Hooker Headers and your source for same! Are your cylinder heads straight or angle plug type? I have AFR-195 angle plug heads. Which engine mount kit did you use to mount the V8? Was it JTR conversion kit? That is what I have and am interested in your V8 installation. Do or did you have header interference with the Hooker Headers? Please advise and don't spare the words. Thanks.

dr_hunt: With all that has been said, belts and chains are not as good as gear drives. Smokey Yunick recommended gear drives for driving the camshaft. Enough said.

Grumpyvette: Latest news. Rebuilt the Holley 650 carb. Found some crude blocking what appeared to be the idle fuel port. Disassembled, dunked in carb cleaner, traced and cleaned all passages with aerosol can of carb cleaner with fine tube nozzle. Reassembled carb, assembled to engine. Started engine and set timing more advance according to timing light with no distributor vacuum. Still need to do more fine tuning checking mechanical and vacuum advance. Now it seems to idle just fine. Set idle jets to 2 turns out and left at that value. All this because of crud in the carb. Once cleaned runs fine. Engine is on a run-in stand with no mechanical load, only flywheel mounted. Have about 1/4 of 5 gallon quantity gravity tank and carb fuel bowl level below site plug and engine runs fine. Have a LARGE aluminum radiator and Ford Tarus two speed fan wired to HIGH speed behind large radiator and it still does not take long for the temp gauge to go above 180 degrees with a few minutes of running. Need to sort that situation out.

Grumpyvette: Have already entertained that thought. Will pick up another carb or rebuild the Quadrajet already broken down. I have already studied the Quadrajet and it is relatively simple and I don't understand the Holley to the same extent. Opened up the Holley and found crusty stuff. Somewhat difficult to find a rebuild kit for the Holley.

dandyZ: Just to reinforce what Grumpyvette has said, I wanted to acoustically record the gear whine at the Knock Sensor location to characterize the frequencies emitted by the gear drive. The knock sensors are piezo electric devices that are tuned to output a voltage at certain narrow band of audio frequencies. I think it was Smokey Yunick that said if you could see a worn timing chain you would see it flapping all about and it would be alarming to the trained observer. This is one, if not the primary cause, of ignition spark scatter in the SBC engine. The whine is a byproduct of the straight cut gear set they use. I used the Pete Jackson quiet type and it is noticeable but not overwhelming. Secondarily, I went to a Big Block oil pump because it will cause less spark scatter than an SBC oil pump. You add up the FACTS then make your decision.

rucus01: Understand the need for fuel pump and pressure regulator. Will attempt to pressurize the jerry can to a regulated 6 PSI. As said, the engine runs fine above 2000 RPM. Already stated that the ignition will fine tuned once the idle situation is fixed. Advancing or retarding the ignition did not cure the idle situation. Talked to a local performance engine builder and he recommended that the carb idle circuit is not functioning properly perhaps due to the low fuel pressure. Tearing apart the carb and the primary fuel bowl has some crusty stuff on the walls. Hard to find a minimal rebuild parts kit with primarily gaskets etc. Power valve feels OK. Need to test with vacuum pump and gauge. Don't want to spend much money on carbs as I would like to go to Electronic Fuel Injection (EFI) which is infinitely adjustable.

Grumpyvette: Thanks for the assistance. The plenum vacuum is 15-17 inches. The valves have been adjusted cold to .016. The Carb is the big unknown here. Used it on a 350 Vortec with the same carb and the 350 seemed to run OK. A 5 gallon jerry can is sitting above the carb partially filled with fuel the bottom of which feeds the carb so pressure is minimal. Fuel is visible at boosters. Jet size unknown. Suspect 67F/73R. Cam timing checked. Plugs at .045" gap. Engine runs smooth from 2000 RPM on up. Just does not want to idle below 1500 to 2000 RPM. The only other carb immediately available is a Quadrajet in the process of being rebuilt. Battery voltage comes from a running truck (13.8 volts) as the test stand has welding cable and clamps for power sourcing from a battery in a vehicle. Distributor is a nearly new MSD Street Fire 8362 HEI type with only short run times on it. Ignition timing is ball parked around 10 degrees advanced for now until such time as I get it to idle and check and set centrifugal and vacuum advance. Just wondering, does the 650 CFM holley idle circuit dependent on the primary power circuit??? That is to say, if putting a larger size primary jet enrichens the idle circuit??? Please advise. Thanks.

Grumpyvette: Further run-in news. Plugged the PCV vent and ran the engine. Now if I modulate the choke diaphragm to about 1/4 open it will run smooth but about 2000 RPM. Lowering the throttle, the engine will quit. Closing the choke further will get it to run rich, opening more than 1/4 it likes to die also from 2000 RPM. The carb is a 650 CFM vacuum secondary Holley. It does not seem that the idle adjust will cure this situation. It has a high lift 236/242 .05 duration cam 383 SBC. Need your experienced suggestions PLEASE.

Sparks280Z: Use a return type regulator. http://www.summitracing.com/parts/AEI-13301/

Grumpyvette: Ignore the previous post by myself. Thought I had left a pipe plug out of the intake manifold. Just went to look at it and found the PCV hose disconnected at the carb, thus the large vacuum leak. Thanks anyway. Will run it again tomorrow weather permitting.

Grumpyvette: Now I really need your help. Just starting to run the 383 SBC on a run-in stand. Got the ignition timing close to where it should be. The problem is that about below 1500 RPM the engine dies out. The carb is a 650 cfm Holley and it ran a 1998 Vortec 350 SBC on the engine stand from what I can remember was OK. Seems the only difference is the Vortec intake versus intake for AFR 195 cylinder heads. Hard to imagine a big vacuum leak as the plugs show it running rich. The camshaft is a solid roller 236 intake and 242 exhaust at .050. Need your suggestions. Need to get this thing to idle. Please provide several possibilities. Thanks and please advise.

dandyZ: The small amount of noise on the quiet Pete Jackson Gear Drive as stated by Doc will be overrun by the exhaust noise. There is nothing better than this gear drive to eliminate distributor spark scatter. Just now running a 383 SBC with the Gear Drive on a test stand and the muffled exhaust is louder than the noise from the Gear Drive.

Braap: Thanks for the response. I never thought about the area and volume of the 4 valve per cylinder advantage which is very technically positive. With the extra chains and extra valves that makes the engine more mechanically complex and bulkier in the engine compartment. The GM Gen IV small block has variable valve control also, to what extent I am not certain. The less moving parts there are to an engine the better.