Noobie's 510 project

[DADZSUN]

Dude, you rock!

I`ve got to get off my a$$ and update this thread eh?

Mini update: KA24e block is getting freshened up and bored as I write this, nothing major 89.5mm slugs. The new motor will be running the 240SX SOHC fuel injected system, lightened flywheel with mild JWT cam.

One interesting discovery that I can post is that the KA24e truck 5 speed tranny does NOT require cutting of the tranny tunnel. It's maybe 3/4" longer than OEM, which unfortunately means the driveshaft still requires shortening.

The build/installation will be documented and posted.

[DADZSUN]

I meant to upload this last fall, but given that it's spring and Solo2 is a few weeks away, maybe now is a better time eh?

I have quite a bit of Solo2 experience but had taken a few years off. I was little surprised how rusty I had become but things started to click after the 2nd evnet - my orange beauty took 3rd in it's class.

At the time I was running L16 (R1 carbs), lowered & moderately stiffer springs & dampers, 280zx brakes, Dogleg tranny, 3.7 Clutch LSD, 14x7 Watanabe wheels on 195/60/14 Azenis 615K.

Door Mount - http://youtu.be/sWFSuN5UiHA
Hood Mount - http://youtu.be/QYC01sngJiE
Roof Mount (reverse course of previous two) - http://youtu.be/eb5zb7gYaEg

I'm fighting *really* hard to avoid the temptation to make this a Solo2 beast. I've done the same with previous cars and have won championships, I've regretted how unstreetable they had become. As much fun as the 510 is to throw around, I really want to make sure it's still fun for long backroad cruises.

[RonM]

[quote="DADZSUN"] I'm fighting *really* hard to avoid the temptation to make this a Solo2 beast. I've done the same with previous cars and have won championships, I've regretted how unstreetable they had become. As much fun as the 510 is to throw around, I really want to make sure it's still fun for long backroad cruises.[/quote
In support of your fight I can say its impossible to have the best of both in one car. But... if your willing to make a few strategic compromises around the edges surely you can satisfy both needs. You may not have a daily driver / Solo 2 championship car, but adjustable pre-load damping shocks and two sets of shoes; one for track and one for street will go a long way in expanding the crossover-ability. I'm no instigator though

[DADZSUN]

Wow, another 8 months since my last update. Thankfully, the 510 has seen lots of action this past season.

I realised late spring that the KA24e rebuild was going to take longer than expected. Rather than rush and make a mistake, I threw the high compression L20B back in. I was planning on running a few other upgrades along with the KA so I took this opportunity to try them out on the L20B to get a better perspective on their performance.
1) eBay lightened flywheel and clutch from a 240sx. This setup worked well on a dogleg - the only thing I needed to do was grind a guide-pin off the flywheel.
2) Electric fans along with Painless switch. I'm not entirely sure how well this setup worked, the rad cap has beltched a few times due overheating from excessive early timing (my dizzy's rotor actually slipped from the oil-drive causing the timing to 'walk'). I'll have a better idea how this setup works with the larger eBay Al. radiator and brand new cap.

This past summer/fall I also had a chance to take the car autocrossing some more. With each passing event I shook more rust off my 6+ year Solo2 hiatus and became more confident in how the car behaves at the limit. By the season-ending event I brought my Azenis-shod car to within 1.77 seconds of FTD (for 'normal' cars) and 3.26 seconds off a Formula car driven by a former National Champ. Results are attached. Clearly with a few simple upgrades this car can easily be fighting for FTD.

As for Solo2 setup, there's unfortunately little to document. I still have no idea what the alignment is, I run the maximum camber the plates will allow up front as well as lots of caster thanks to the adjustable Futofab T/C rods. I ran the Tokico blue fronts at '1' and the rears at '2'. Tire pressure is 34psi front & rear on 195/60R14 Azenis 615K (2nd season). A have a stock front sway bar with crumbled poly bushings LOL. Speaking of poly bushings, this winter I'm swapping the front and rear control arm poly bushings back to rubber as I felt the current setup would bind then release - causing a bucking/porpoising motion in the car when at the limit and applying throttle.

The car is now parked and the front fender crash structure is being repaired. The KA24e is *finally* buttoned up and will be installed over the holidays. 'New' period-correct 260z seats will be installed as well. Postings/pics of these improvement will be coming soon.

[okayfine]

'New' period-correct 260z seats will be installed as well. Postings/pics of these improvement will be coming soon.

E30 BMW seats aren't period-correct, but they look like they belong and are miles ahead of Z seats with regards to lateral support. Given the car's time on the autox courses, you might see what you can find:

[DADZSUN]

That may be the case with the E30 seats but the 260z examples I snagged have a noticeable improvement in bolstering compared to the E46 seats I previously had installed. An added bonus with the 260z vs E46 is the 35lbs weight savings, the backrests actually folding forward enough to access the rear, and overall lower seat height.

While I'm trying hard to not let Solo2 dictate modifications to the car, if I do require additional securement while autocrossing I'll likely go with a Schroth Rallye 3 harness. I would install an eyebolt on the unused rear seat shoulder belt provision, that way the harness can be quickly unclipped for normal rear passenger use.

[DADZSUN]

It's time to put a little meat on this thread's bone.

With my KA24e build, I managed to secure a '91 D21 block. The basic differences with the 240sx example is a non-girdle bottom and non-iron 'skirt' around the rear of the block so the starter mounts on the tranny vs the block, the pistons use press-in wrist pins vs clips on the 240sx, and the cam is a little less aggressive to provide more low-end truck torque. The other main difference is the a rear-sump pan so the original idea was to run an unmodified cross member. Unfortunately the pan was a little too deep, a couple of inches lower than the cross member making it vulnerable to rocks/speed bumps etc...

The decision was made to still modify the pan vs running a reversed cross member, a new front sway bar and sourcing a 240sx front sump pan. HUGE thanks to Andrew for helping on this. First step was to remove the cross member from the car and bolt it to the block on the engine stand. Next the area in question was cut out and a cardboard mock-up was fabricated. Once complete I installed it and the block into the car to check for steering link interference etc...

All these work/pictures were done last winter/spring in the rush to try and get the KA installed for summer.

[DADZSUN]

Moving to this winter, with all the welding the pan warped a bit so I bolted everything down to the block w/o a gasket to try and 'pull' the pan into place. It actually worked quite well.

I then rotated the crank to ensure there was clearance, good thing I did because the back counterweight on the crank was hitting the pan. A little 'persuasion' with a hammer cleared things up.

With the pan finally ready, I POR'd the inside and outside to seal her up.

The oil pick-up was then shortened to fit the shallower pan and also POR'd.

[Sleepys-14]

Great job! Looks like a pretty sweet setup ya got there. I like what you did with the oil pan. Also, keep racing!

[DADZSUN]

Moving on to the engine rebuild, the block I sourced was quite a mess. I tried honing but couldn't get the finish I wanted so the decision was made to bore up to 89.5mm.

I've never done an engine rebuild before so frankly I didn't have a clue how to go about doing so. The Factory Service Manual (FSM) is handy for torque settings but it's so much easier to actually 'see' how things are done. Cue in the rebuild video from hpvideo.org. It's very good video with clear explanation of the step-by step disassembly, cleaning and reassembly. The narrator also included torque settings (I still double checked against the FSM) which is good. Added bonus was that the video was specifically rebuilding a pickup KA24e.

The timing chain and tensioner were replaced during the rebuild. I figured out after mounting that the black links in the chain needed to line up with the cam wheel and lower sprocket drive (one thing the video had failed to mention but the FSM gave me heads up). With that setup it's pretty much a no-brainer to get the cam timing properly.

The eBay rebuilt head was mediocre at best. One of the valve spring washers wasn't seated properly and they had stripped one of the cam tower bolts during reassembly. This should have been no surprise to them as 8 (!) of the 10 other tower bolts were retrofitted with heli-coil type setup. Naturally I had to go out and get a kit ($70!!!) to complete the install. The reason why the cam towers were removed was to install a brand new Jim Wolf Technology S1 cam I purchased for cheap on the internet. I didn't really care too much as to the specs (E256 / I248 .422") as I simply wanted something a little meatier than the pickup cam which is supposedly less aggressive than the 240sx cam.

[bertvorgon]

Hey, keep up the good work! I proved you can have a championship Solo car, and still keep it streetable ( glad I did!), even getting some FTD's and beating some Formula cars.

Once a car is turned into a full on race car, it is very hard to take it back...and NEVER, EVER, get rid of any parts, that can make it streetable again.

[DADZSUN]

Thanks Keith.

The added torque from the KA should help shave another second IMO, not only for gains in acceleration but the ability to use the throttle (finally!) to rotate the car. I expect a minor change in balance with the KA & tranny adding some weight, but the planned R1 carb setup is over 35 lbs (!) lighter than the EFI setup (I've got both and weighed everything to compare) so that should help offset some of the gains.

I think my plan will be to sort out the engine this year and play with suspension settings and go R compounds next year. If things go *really* well, I may grab some Rs and drive out to PEI this summer for the Nationals on a work-vacation trip. Having FTD'd at the Nationals in a porty BSP 350z, I'm confident the I can push this little Datsun to challenge FTDs at local/provincial events (at the very least). Like everything else when it comes to racing, it's just a matter of how much I want to spend.

[DADZSUN]

OK, we're finally catching up to where I'm at now.

So the KA is nearly done. By removing the EFI system, I've got to make up some blocking plates to cover a couple of spots on the timing cover as well as the EGR tubes on the exhaust manifold.

For fuel, I've been running '99 Yamaha R1 motorcycle (Mikuni) carbs with decent success for the past 2 years on both my L16 and L20B. These carbs are a very simple and extremely responsive setup so I've decided to try them on the new build. When mounted on a KA, side draft carbs are known to really help add some ponies to the top end compared to the EFI induction (I'm hoping for 170-180 crank HP). Added responsiveness is also a benefit - and don't forget the sound!!!

It's been well documented (google 'Ratsun R1 carbs') how to mount R1 carbs on a KA. In a nutshell, you can use an electronic/points L series distributor on a KA24e SOHC timing cover with minimal modifications (swap oil pump drive shaft to an L series then tap the timing cover to mount the L series pedestal, fabricate a small bracket to secure the lower mounting point). That is the route I'm starting with and then potentially move to a MegaJolt setup using a modified ASP underdrive pulley to fit the 4" ID timing wheel and the R1 carb's OEM Throttle Position Sensor (TPS).

The second piece to mounting R1 carbs is an intake manifold, cue in Bogg Brothers from the UK. The pics below are a first generation manifold. A second one has since been received which has larger coolant opening and a flare in the backplate for better coverage over the coolant port on the head. Bogg has been great to work with considering they don't have a KA to work with, nor have they ever seen one. I sent them a hacked up OEM manifold which made the trip to/from UK twice (long story) and was eventually discovered to be bent LOL. The Datsun OEM 3-3.5psi fuel pressure has been deemed sufficient for R1 carb use, but for the KA I'm going to run an external Yamaha R1 fuel pump (includes auto shut-off) to ensure that all potential tuning variables are addressed. Tuning of the pilot/main jets and needle setup will be done with an Innovate wide band O2 sensor.

Over the holidays I'm hoping to pull the L20b and dogleg and fit the KA and tranny. I actually have two KA trannys, one is from the pickup which is quite short (approx. 1 inch longer than the dogleg) and the other longer unit from a 240sx. I'm going to try the 240sx tranny first to get the shifter further back into the cabin for a more natural reach - so there will be some cutting and welding on the tunnel. I've got to finish welding up the one engine mount which is a modified L20B mount. I've also got to read a little more on engine angle so that driveshaft vibrations don`t become a problem. Once complete I'll take measurement for driveshaft length and send it off to get shortened.

[bertvorgon]

As I don't see a roll bar in your car, you must be very wise what type and WHERE you mount an after market shoulder harness. You DO NOT want to go over the seat, then down to the floor. With out a bar at least as high as your shoulders, you could/will break your collar bones should you have a shunt.

Best bet would be to go straight back to the rear parcel shelf, if you have to, then put some large washers ( 3") under the bolts to spread the load.

[DADZSUN]

There is actually an un-used OEM shoulder mounting point on the C pillar - perfect for the Rallye 3. I tested it with the front shoulder belt.

It might be the one in my pic below but I seem to recall it was a little higher and more forward.