RoadRace

We have a short track, 1.3 miles. it has a 1/4 mile straight. best trap speed so far is 160kmh, or 100mph on my track addict app....but that being said, it was nosing over at 6000 and falling on its face at 6200rpm in 4th, i was nursing a timing or jetting issue. The funny part is that when its all perfect, probably wouldn't be more than 105 lol. agree, @iceman510 123mph is impressive!

hi - the request for a spacer when going to a lower ratio is based on a typical salisbury-style differential. They use shims and spacers to position the ring gear carrier along the axle centerline to achieve the correct engagement pattern or mesh with the pinion. this is because there is only a limited amount of space to move the carrier, like .040" for an example. You want to use as little a shim as possible, like .012" for example. When going to a gear set with less pinion teeth, that makes the root diameter of the pinion gear smaller, meaning you have to shim the carrier closer to the pinion than it was before to get the pattern you want. OEMs typically use 4:1 as the change over. 2 and 3 series ratios will use one carrier, 4 series and above uses a different carrier that puts the ring gear closer to the pinion, to compensate for the reduced number of teeth, and subsequently, smaller root diameter. When a shop sees you want to swap a 3:xx to a 4:xx, thats like a red buzzer going off and typically, with a salisbury diff, that's going to need a different carrier (not always because they do make thicker ring gears just for this type of application), BUT, you can buy a ring gear spacer, typically .125 or .188, to space the ring gear over, thus not requiring tons of shims (that wouldn't fit anyway). Now, that's all for a Salisbury diff - like a chevy 10 or 12 bolt - and the Datsun uses a Hotchkiss design, like a ford 9" - the "drop out 3rd member" style, where these shims don't come into play. That's because there are really big threaded adjusters in the main bearing caps that you screw in or out to move the carrier on the axle centerline to where you want it in order to get that pattern or mesh you need. I have never set up an H190, and the pic above blocks the part where you would see the adjusters - but I feel like there is some mis-communication at the shop you are dealing with. hope this helps 🙂

i've seen it as well, interesting on an anecdotal level, but thats all. For B/Sedan race cars like mine, most of their stuff is expensive and illegal and really doesn't yield an advantage anyway. The stuff they sell that is legal has been offered by several other companies for a long time already. If you run a modded street car, i guess its up to you - this looks like a place to spend money to be different, not really go fast and not solving any problems. Trying to improve on the handling of a 510 is not a great business model....the car is already well supported.

also, while using the piston to square the ring for checking gap is good, its a bit clumsy and can lead to errors like thinking you've done it enough that you know its square. its not personal, its just being human, the piston method is good, but you can't make a visual check to verify its perfectly square because the ring is blinded by the piston. I use a depth setting Vernier caliper locked at a pre-set height as measured from the deck. I can square the ring at multiple locations and physically pull the ring up to the stop - pushing it down isn't the problem, being able to pull it up to the stop is, and you can't do that with a piston, and you also have to keep pushing it down with the piston to make sure, and the piston wobbles at the top, the OD at the top can be smaller than the OD at the pin, depends on the piston - even though its impossible to make absolutely sure, and for consistency's sake, you'd like to check the ring gap a little closer to the top as you can see and feel what your doing better. just my 2 cents....like I said previously, I'd run the extra ring gap so how critical can this be, right? But this is the method I use so I don't have to make those decisions...

when buying a "file-fit" ring set, they typically come in .005" over. meaning if you have a .030" piston, and order a file-fit ring set, they will come in .035" as they are meant to be installed to your specs. while i agree that the .023" ring gap was a bit lofty, if the 2nd ring came in Ok, its not the end of the world. When running boost or nitrous, you're going to open it up to that anyway and its not going to cause any smoke or anything.

the flat spot on the rocker to the right is a concern, the pitting on the rocker to the left is also a concern. while the pattern on the right is closer to centered, the risk to damage the rocker pad and cam is there.

right - sorry about that, i see what i did there, s/b steering arms. Right, these put the steering rod/tie rod in a neutral position at the start of the camber change curve, minimizing bumpsteer. hard to tell from this terrible picture, but the wheels are pointed in the right direction at max load. NOTE: one of the best suspension mods I've done was also the cheapest, and that was Delrin bushings and roller thrust washer for the idler arm, that really made the car more predictable, easier to drive.

DP Racing sells them: https://www.dpracing.co/datsun-510-front-suspension-1 they also sell the 1" spacers. i never did a build thread, but this is also shown in the "how to race your datsun" bob waar book

on my last dime, i used spacers from Kelvin Dietz, they were 1", but i had also cut the springs. For the current dime i am using "bump-steered" control arms, no spacers.

received weber tuning parts, jet kit, chokes, E tubes and cam tower spacers. Finished the intake port matching and started cleaning up the head port work. need to set up the tappet shim height, order the sims and retainers for the thicker shims next....luckily its still -14C (7 Freedom degrees), so i don't feel the pressure to get it done yet lol

I recently got an old-new intake for my race car. the original one was cast for 40mm carbs and opened for 45’s, breached, welded - it worked but was ugly and potentially leaking, causing the tuning problems i was having. on eBay recently was a period correct SK intake for 44’s, so my Weber 45’s should be dreamy. to start this off, I will try and make it as simple as possible – I have phoenolic spacers behind the rubber gaskets for the 45 mill carbs, I’m using those for the template. i made small alum alignment pins to hold the spacer in place, and i scribed the line onto the intake. i used a tulip shaped carbide burr to get close and shape the transition, the a larger 1” diameter sanding drum to make a smooth radius. Well, three of the cylinders were perfectly centred and only required opening up, The number one cylinder was offset by almost 2 mm, emphasising the need to verify alignment on Parts like this.

Yes, 2mm im thinking just calling wiseco, as suggested above might be the best way thanks again for your input!!

hey - thanks - ya, Wiseco made them in oversize, hi-compression, but they don't list them or the rings on their website. i want to hone it and put in new rings for the season....but that's turning out to be more of a challenge than i thought.

hi - I'm looking for piston rings, 4mm 2mm 2mm, not sure what brand in there now, its wiseco pistons, but on the wiseco site, they don't have the L series engines listed. total seal doesn't have the overbore i need. any suppliers you can point me towards? thanks