Datsun Roadster Forum-311s.org

So, I have had this car since around 1996. Right now I am running 240Z SU's on a hogged out 1600 intake. She runs fine but has always been a bit rich. Dave Premo hooked me up with a set of 40's he went through for me. I am using the JAM intake as the real deal is unobtainable at this point. The real issue was the linkage on the JAM intake. JT made me a sweet center linkage setup as noted in another thread. I did some searching on the forum and found shifty's solution. I ordered some bits from McMaster Carr-
Multipurpose 6061 Aluminum Tube, 3/8" OD, .277" ID, .049" Wall Thickness
Zinc-Plated Steel Coupling Nut, Low-Strength, 5/16"-24 Thread Size
Set Screw Shaft Collar for 3/8" Diameter, Black-Oxide 1215 Carbon Steel
3/8"-24 RH Male Shank, 3/8" Ball ID, 1-1/4" Long Thread
21/64", 4-19/32" Overall Length, 2.3" Drill Depth, 135 Degree Point

I needed to make some spacers so at first I purchased 1/2" thick seaboard but the linkage was still hitting the manifold-so I went with 3/4" and that worked well. The material is easy to drill and bore with a hole saw. Purchased the Seaboard from Amazon-Seaboard High Density Polyethylene Sheet, Matte Finish, 3/4" Thick, 12" Length x 24" Width, Black

I then had the machine shop at work make me up an aluminum metal plate to bolt the throttle cable stand to and the idle adjustment screw. I used the coupling nuts to space the plate away from the back of the linkage. I used the bit to drill out the front set of holes and then tapped them out so the eye bolts would work in those holes. The back holes I tapped out and put bolts in to seal them off.

I purchased a well used 1600 intake with the linkage rod intact. I robbed the idle tab, the cable drum and the connecting ball socket from it. Will bead blast it and throw it back on Ebay.

I ordered some air horns for 40's from Hong Kong and the Ram air foam filters came out of England. So, I think I have everything ready to remove the 240Z carbs and put the new 40's on. It is just starting to warn up here in the mid-west so hopefully I can get them installed soon. Here is a pic of the completed intake carbs, air horns and foam filter.
Next up will be a bung in the exhaust and put a wide band O2 sensor sensor like this one Wide Band 02 Sensor
so I can get the carbs tweaked for maximum performance. Another great suggestion by my good friend David Premo.


S
More to come once I get them installed.

Looks nicely sorted Steve!

I like your solution to linkage! Do you get flex on that long shaft run?

Thanks. No flex at all. I will find out how well it works once I get it installed but I am pretty confident it will work just fine.

S

Suspect it will sound as good as it looks!

Is there a vacuum source for the valve-cover-crankcase-breather-tube?
JT68 mentioned the absence of such an item can cause, or exacerbate, a leaking rear main seal.

Innovate makes a nice set up. It does not look like you will have a gauge for ongoing monitoring but that's up to you, and does require finding a spot for it. However, having that info has been helpful to me as I monitor my engine and helped with trouble shooting on the road. The Innovate is a spendy kit too, though it probably has some features mine may not have (Glow shift wide band). Regardless these will make carb jetting much easier. Have fun, you'll LOVE the carbs!

Just noted the above mention of the vent tube. One option that Carl (Roadster guru from Canada) did was to route and extend the hose under the car so that the air traveling under the car causes a vacuum and helps pull out fumes (end of the hose must be in the airstream). Not very emissions friendly, but it works for me while I wait for when I make my air box again.

The 1500s and early 1600s had a road draft tube.

Right now I have a small K&N filter on the valve cover vent. My rear main leaks a little but they all pretty much leak there. At least that has been my experience. I may try the road draft tube.

S

The 2L aircleaner assembly also works with this setup

So update to the 40 install on my stroker. I tried them on a month or so ago. Install went easily and everything lined up. The problem was I could not get the idle below 4,000 RPM. I did not leave it there long but it was pretty frustrating to say the least, Spoke to Dave P and he suspected I had a major vacuum leak. I used the rubber hose trick and could not find any vacuum leaks. Dave told me to take them off and go back to the SUs and he would help me before Shasta.

Roll forward and I hooked up with Dave the Saturday before Shasta. He looked things over before we tried the install again and found nothing glaringly wrong. The two stud holes that hold the bottom of the intake on the block were a wee bit tight when I first tried the install. I drilled them out but Dave said it was still too tight and took a bigger bit to enlarge them. He suspected the tight fit was my issue and that even though I thought the nuts were working to hold the manifold against the block it was more than likely hung up leaving a slight gap. After the holes were drilled out the manifold slid right into place with no binding. We tightened everything up and put the heat shield on. We got it started and no more high idle. Dave worked his magic adjusting the linkage and the air flow. There are still some things that need to be done but seat of the pants dyno and she runs like a rocket ship. What ever jets Dave put in the carbs when he built them has the car running strong with no hesitation. I love the sound of the mik's at speed.

Dave was pretty impressed with my linkage setup. I am happy with it as well. We cruised up to Shasta taking the long way as we had intended to cruise through Mt Lassen but the road was closed at the summit. My car ran flawlessly and I seem to be getting a bit better gas mileage than I did with the 240Z SUs.

I had to leave Shasta early Saturday morning as we were driving back to Iowa early Sunday morning. The car ran just as well going back to Antioch and I had zero problems. We still need to work a few minor issues out but I am very pleased overall.

Dave definitely knows the Mikuni's well and was able to resolve my issues. I am amazed he got the jetting so close by bench building. If you need anything Mikuni related Dave is your man. He knows a whole lot of other stuff as well. Plus he is a super nice guy. Thanks Dave for all the help.

Steve

Kudo to Dave, and glad you had a great run Steve!

Steve you made it to Shasta!
Does the car feel faster with the Solexes?
I do remember it was fast with the SUs

16 years ago:

What does she look like now?

Alvin,

Yes, the car is faster with the Mik's. I should have done this years ago. Yep, made it to Shasta for the Thursday/Friday shin-digs. Left my roady in Antioch as I am retiring the end of the year and we will be wintering in California. I preferred the north bay to Antioch but this is how things worked out. Should be able to make a fun run or two.

Steve

Finally got the 40 Mik's sorted today with special thanks to both Dave P and Brian K. Brian redid the JAM manifold for me as there was no way it was going to work with center pull linkage that I prefer to use. Brian had the manifold welded up and then he machined the mounting holes for the studs so they were truly inline. He also did a little surface magic as it was off. Since the material I had used for the isolator's got a wee bit hot Brian made me some machined pieces out of delron. They look pretty sweet. Dave P had me get some 8MM x 1.25 all thread and we made new studs the correct length. The two center top ones protrude out the back so I could mount the 1600 linkage bits. We also made the two outside bottom studs longer and sticking out the back so I could mount the heat shield closer to the header. Everything lined up and there is no more binding at all. Carbs are smooth as silk. I could not for the life of me get the linkage set correctly to idle. Dave P explained to me how to do it over the phone but I just could not get it to work. Dave was gracious enough to drive over to my house this morning and had me dialed in in 5 minutes. The car idles as it should and performs well. We had tweaked on the center linkage a bit due to the issues from the mis-alignment but Dave got that fixed straight away as well. The new single wire alternator performs well. No more screeching alternator belt. I have a few more things to do but the roady is drive-able and ready to roll. Going to try to make a bay area fun run one of these days. Happy new year everyone...

Here are a couple of more pics.

Happy New Year. awesome progress! Enjoy the ride!!