Friday, June 30, 2006
Searching for answers?
It's the end of the month again, which means it's time for me to see if I can read my readers' minds and answer questions they may have. Well, actually I don't read minds, but I can sometimes find what they were looking for on a search engine. And if I know the answer but it's not on my blog, I'll post the answer. This month, we have two interesting ones:
I have a Nissan with a 2-bbl carburetor. Is there any adapter I can get to put a 4-bbl carb on it?
Specter makes an adapter that will let you put a four barrel Holley in place of many two barrel carburetors. It's likely to fit your engine if you have a downdraft carb, but I can't promise it will clear your hood. There are a couple other issues, too. The biggest one is that this adapter is something of a bottleneck - you're still trying to pack four holes's worth of air and gasoline through two holes on the manifold. I would only use this adapter as a last resort.
The best approach, if you can afford it and the aftermarket has one, is to get a manifold designed specifically for putting a four barrel carb on your engine. I'm pretty sure Offenhauser builds one for the NAPS-Z. Wouldn't surprise me if there are a few interesting manifolds out for L-series motors, too. Ebay is often a good source for these.
Another approach is to modify your manifold. Although it's not about Nissans, there is a spectacular illustrated thread on SlantSix.Org about modifying a manifold to accept a different carb. This would be easier if you had a milling machine, but the guy who posted that just used a Sawzall, drill, and Dremel.
How do I install a Pertronix Ignitor?
This part really is an easy bolt-on. I've got one on my Dodge Dart. The short version is that you remove the distributor cap, unscrew the points, and remove the rotor. You replace the rotor with a new one from Pertronix that has a ring of magnets around it. The Ignitor attaches using the same screw that holds the points in place. Wire it up (one wire to the negative coil terminal, one to the positive), adjust it so the rotor doesn't rub on the module, adjust the timing, and you're done. The hardest thing on my slant six was clipping the distributor cap back on - if you've worked on a slant six, you'll know how little room there is to work on the distributor. I find it easier to get the cap back on if you remove the oil filter.
I have a Nissan with a 2-bbl carburetor. Is there any adapter I can get to put a 4-bbl carb on it?
Specter makes an adapter that will let you put a four barrel Holley in place of many two barrel carburetors. It's likely to fit your engine if you have a downdraft carb, but I can't promise it will clear your hood. There are a couple other issues, too. The biggest one is that this adapter is something of a bottleneck - you're still trying to pack four holes's worth of air and gasoline through two holes on the manifold. I would only use this adapter as a last resort.
The best approach, if you can afford it and the aftermarket has one, is to get a manifold designed specifically for putting a four barrel carb on your engine. I'm pretty sure Offenhauser builds one for the NAPS-Z. Wouldn't surprise me if there are a few interesting manifolds out for L-series motors, too. Ebay is often a good source for these.
Another approach is to modify your manifold. Although it's not about Nissans, there is a spectacular illustrated thread on SlantSix.Org about modifying a manifold to accept a different carb. This would be easier if you had a milling machine, but the guy who posted that just used a Sawzall, drill, and Dremel.
How do I install a Pertronix Ignitor?
This part really is an easy bolt-on. I've got one on my Dodge Dart. The short version is that you remove the distributor cap, unscrew the points, and remove the rotor. You replace the rotor with a new one from Pertronix that has a ring of magnets around it. The Ignitor attaches using the same screw that holds the points in place. Wire it up (one wire to the negative coil terminal, one to the positive), adjust it so the rotor doesn't rub on the module, adjust the timing, and you're done. The hardest thing on my slant six was clipping the distributor cap back on - if you've worked on a slant six, you'll know how little room there is to work on the distributor. I find it easier to get the cap back on if you remove the oil filter.
