Pyro

81, 82, and 83 non-turbo 280ZX with F54 blocks and P79 heads

Just bolt on a bigger clutch master cylinder. Tilton or wilwood. Get a JTR V8 conversion manual. The manual explains these little details. However, the manual is written for the first gen Z's but most stuff will apply to the ZX.

I think the small journal 327 rods are plenty strong. I have a set in my 350. The racing machine shop did an off-center grind job on the stock 350 crank. In this process, the large journal are machined down on one side of the crank to small journals. This increases the stroke of the crank by 0.070". So the stock 3.48" stroke has been changed to 3.55" which makes a 362 cid @ 0.030" over bore or a 368 cid at 0.060" bore. Finally the tops of the pistons were cut down to make a zero deck block. I didn't ask for this work, but they had one already on the floor I shift at 7,200 to 7,400 rpm and spray a 175 shot of N20. I have been abusing the short block for over ten years now without a rebuild. The engine uses pump gas and does 110 mph in the 1/8 mile and 135 mph in the 1/4 mile. So, I wouldn't worry so much about journal size. Just do a high quality rebuild and put the pedal to the wood. In fact, I have read that small journal engines have less internal friction due to less bearing surface area. But for a street/strip car, it is spliting hairs in my book.

I don't think those puck type clutches like slipping too much. Mostly because they are typically made of ceramic or metal materials. Maybe the stage 2 Spec clutch would be better. Stage two is a Kevlar disk made like the stock design. I have a stage 3 Spec 6 puck or my turbo 280Z and it chatters a lot and is super grippy. I can't image slipping that clutch. I guess talking to the spec tech guy would be helpfull. Keep us updated.

Is that a straight T4 or a T3/T4? What compressor wheel are you using?

That is good news. The last thing you need to do is connect the tube from the valve cover to the intake tube between the AFM and turbo. You might need to lean it out after that.

Mallory comp 110 is very quiet. I can bearly tell its is running with the engine off! The Mallory comp 140 is a little louder than the 110 and requires a regulator. I hate those holley pumps too! Loud as hell!! The 110 should be enough fuel for your 327. I ran a 110 for years on my 400+hp 362 cid with a 750 holley carb and 7K shift points with out any problems. However, be ready to pay 180.00 for the 110 and 230.00 for the 140.

Mallory comp 110 is very quiet. I can bearly tell its is running with the engine off! The Mallory comp 140 is a little louder than the 110 and requires a regulator. I hate those holley pumps too! Loud as hell!! The 110 should be enough fuel for your 327. I ran a 110 for years on my 400+hp 362 cid with a 750 holley carb and 7K shift points with out any problems. However, be ready to pay 180.00 for the 110 and 230.00 for the 140.

Since you are using all the turbo efi electronics then I would say the FMU is set way too high. Try ramping to only 45 psi at 13 psi. Yep, could be a vacuum leak. Z's will lose vacuum from just about everywhere. I have heard of vacuum leaks caused by bad rear main seals! Does your engine die when you remove the oil cap? It should if the vacuum system is working correctly.

It could also be an ignition timing problem. Use a timing light to verify the timing is advancing when you hit the throttle. A common mistake on GM engines is to plug the vacuum advance in the wrong port on the carb. The correct vacuum port WILL NOT have any vacuum at idle (called ported vacuum). Vacuum to the vacuum advance is only produced when the throttle blades are opened. Vacuum on this port is taken from above the throttle blades (not manifold vacuum). You can feel the difference between the two vacuum ports with your finger as the engine is running. If you have the vacuum advance on the wrong vacuum port then the timing will retard when the throttle is opened which will cause a bog.

Becareful when going for the cheap fix. It will end up costing twice as much with 4 times the work. I'm always fighting my "cheap instincts" but still have a long list of cheap fixes that I ended up doing agian, "the right way", costing a lot more money and time than I wanted to spent (doing the job twice). "Do it right the first time" I tell myself, but still slip every once in awhile. I would recommend saving up some money and converting a 3.90 gear R200 into a LSD. Go for the Preicion Gear center section and new axle bearings and seals. So, live with the 1WD for awhile and save some money. FYI, new tire rubber helps with 1WD traction.

Well, if you are running 21 degrees base timing then i would think you are just running super rich. I don't think a lean mixture will not make a manifold glow red. How is your gas milage? How does you car idle? smooth or a little rough? Have you done a compression test lately? A stuck open exhaust valve could do that. What is your fuel pressure at idle? Are you using turbo injectors with a Non-turbo ecu then a FMU to raise the fuel pressure? If so, the turbo injectors will make your car run very rich at idle. A non-turbo ecu can use turbo injectors if you lower the pressure to 15-20 psi at idle. Also, a bad water temp sensor or a bad connection at the water temp sensor will cause a very rich condition.

Your timing maybe be retarted. A late firing ignition causes a lot of unburnt fuel to be pushed out the exhaust valve and then it finishes burning in the exhaust manifold. That is how they make those pretty glowing photos. A rich mixture and majorly retarding timing. My V8 Z will make the headers glow cherry red unless I use at least 20 degrees of initial timing. Try advancing the timing. If it pings then you should reduce the amount the distributor can advance so more initial timing can be used. Or get a boost timing retard I welded up my distributor advance slot in my 76 turbo Z so it advances only 8 more degrees after idle (stock is about 18 degrees more mechanical advance). Then, I set the initial timing at 20 and it advances to 28 by 3500 rpm.

Yes, V8 GMT5 are hard to find. Don't get hung up on WC and NWC. I have ran both and couldn't tell any difference. As long as it is a trans from a v8 car then you will be ok. Plus, by making easy shifts and not dumping the clutch you will triple the life of the transmission. I have talked with shops that build T5's and they say the NWC T5 is actually stronger than the WC. Also, the gmt5 is beefer than the mustang t5.

The 280 tach can be adjusted for a V8 but they just don't work very well. I tried it but it never was very accurate. It is better to use an Autometer gage in your dash.

Sounds like you are just having carb problems. But connect the vaccum advance to the right port anyways. Surging when driving at a constant speed is a sign of running lean. The fuel float is adjustable in a quadajet but you need to take off the top of the carb. And the quadajet is a very good carb when working correctly. So is the Holley. Both the holley and Q-jet are very dependable and durable. IMHO, the Q-jet will get better gas mileage if driven slow but worst when driven fast as compared to a holley. But don't ever buy a cheapo carter/edelbrock carb. With the engine off, pump the carb linkage and see if fuel is pumping out of the accelerator pump. Check for vacuum leaks. Use a propane torch without the flame lit. Vent the gas around the intake manifold and carb. The engine will run rough when it eats propane. If you are going to buy a new carb, get a holley 3310, 750 vac secondary. What kind of a regualtor and pump are you using? The Q-jet and holley can handle 7 psi with any problems. Most aftermarket pumps for carbed engines make 7psi and would not require a regulator.

Yes, ford did it different in most cases. I have very little experience with fords but I did work on a few 69 mustangs. I noticed the vacuum advance difference at that time. Being a chevy man it is hard for me to say, but I think the ford system works better. However, in any case, the timing should advance when the throttle is depressed.

That is right. There isn't much vacuum in the manifold when the throttle first opens or at WOT. That is why chevy is using "ported" vacuum. So, under zero vacuum or dropping vacuum conditions in the manifold, the distribitor will still advance. Don't mix up manifold vacuum and the vacumm signal produced by air flow thru the carb. If fact, the lower the intake pressure the higher the ported vacuum goes. So when the throttle is openned, a vacuum is created above the throttle blades which creates a big pull on the distributor no matter how much vacuum is in the manifold. Most cars have maximum vacuum at idle (cars with stock cams). So if the vacuum line is on the manifold vacuum port, the distributor will retard when you step on the gas and make it stumble.

Advancing the timing is starting the spark sooner. When the throttle is opened, the vacuum advance quickly advances the timing to increase cylinder pressure. The mechanical advance is totally rpm dependent. Therefore, the vacuum advance gives low rpm timing advance that is not possible with the mechanical advance. The timing curve is just as important as the fuel curve. Old vacuum and mechanical advance systems are not very good. Modern day ignition curves produce better power, gas mileage, and is ONE of the reasons engines can use higher compression ratios now. The new curves look much different than the old timing curves and are made possible because of computers. New systems normally give a bunch of timing right off of idle and during light loads as you have already mentioned.

It is easy to check. Get a timing light and watch the timing mark on the crank when the engine revs off of idle. If the timing mark retards at first then it is not on the right port.

Well, you can try using one pump. The problem is, the higher the pressure the lower the flow. For example, a pump that can put out 250 gph at 40 psi might only be able to pump 100 gph at 80 psi. This can become a problem when the fuel ratio is controlled by increasing fuel pressure. It would be a good idea to install a fuel pressure gauge if you use an FMU so you can monitor the fuel pressure. If a single pump can't hold the pressure during high load conditions then a helper pump should be used. I use two stock pumps in series (one pump feeds the other) to supply fuel to my FMU. One pump could only manage 50 psi during long 3rd gear runs. Two stock pumps can hold 75 or 80 psi. I'm not 100% sure but I think at 80 psi, both pumps think they are pumping 40 psi each. Reducing the pressure to the injectors might not be a good idea. Low pressure will mess up the spray pattern. You might be able to find the spec for the min pressure requirement for those injectors.

YES, but not quite. The formula for increased flow after more pressure is: The square root of (new pressure/old pressure) then muiltplied by the old flow rate. Check out the RC Engineering web site. so the sqaure root of (60psi/37psi) is 1.2734 and 1.2734 x 260= 331cc 330 cc is good for 330 hp with a 6 cylinder. 80 psi would make 382cc injectors out of your 260cc. (382hp potenial) However, after 60 psi another fuel pump would most likely be required.

Jason, You should get a Bell Enginerring FMU. It only adds fuel pressure under boost. It also ramps up fuel pressure at a ratio you set, 1:1 to 1:10. Goes for 200.00. I use one on my 76 turbo and it gets me by using all the stock 76 efi by ramping up to 75 psi of fuel pressure at 12 psi of boost. I'm sure it would work much better in your situation. Should prevent running rich during normal driving.

Also, check the ignition timing curve. It should advance when you hit the throttle. If you have the vacuum advance on the wrong port it will retard when the throttle is opend and the engine will fall flat. Your carb has two types of vacuum ports. One is manifold vacuum and the other is called "ported". It is a very common mistake to put the distributor vacuum advance on the wrong carb port. GM vacuum advance distributors use a "ported" vacuum source which means it will NOT have any vacuum on it at idle. Vacuum from the ported source is produced when a lot of air passes the throttle blades (like when you give it the gas). Therefore, vacuum is caused by a ventri effect. So when you hit the gas the timing advances. FYI, old fords use the vacuum port on there distributors. I think they did it that way just to be different. Distributors up front, vacuum advance, firing order, ect. LOL

No adjustment nessary in my case. Just plug and play. I'm using the stock T5 fork, stock T5 clutch slave cylinder, tilton 15/16 master cylinder, and a flexible high pressure line that was custom made by a local hose shop. I just followed the JTR V8 conversion manual instructions and it worked. However, when I added a strong pressure plate, I had to reinforce the firewall because it would flex a lot during clutch disengagement! I made a support that braces the firewall to the inner fender.