volodkovich

If CPC thinks that a 1mm anti-reversion step at the manifold flange will cause 'more turbulence and a restriction to flow at the port' then maybe its a good thing you are not getting one from him? That's not really something you want to hear from someone selling $5000 aftermarket manifolds.

They likely make them for a customer in Japan. I noticed a host of different L conrod lengths from a Chinese manufacturer indicating that they are supplying some serious L builds in Japan. I laugh at the Chinese parts fear mongering. Like they don't know how to machine a crank or some rods. Very basic work these days with modern CNC tooling and metallurgical practices.

Hows this coming along? Are you still considering selling the manifolds to select customers? Saw your new video on youtube, nice work!

That is a drag motor from a s30 drag car in japan. Its street registered, run's 55mm ITB's and makes 375hp at the wheels. Yes, you can make that sort of power out of n/a L's without going to stupid bore/stroke lengths - that motor is a LD28 crank and bored to 3.2 litres. You are better off spending the money/time/effort in developing well flowing heads over trying to get more capacity. Buy up ten N42's, a tig welder to weld the chambers and spend 5 years developing them.

Hmm, so i guess l28 valves would make a big difference. Quite a lot of work to get them in though. I wonder if the height difference could be accounted for by machining the seat higher into the head, or running lash caps etc.

I'm quite keen on doing building a mild tuned ld28 for my daily. I guess first thing to do is get a good exhaust onto it. Keen to try a turbo later on, would the injector pump from the rd28t be a good upgrade? (so wouldn't have to worry about modifying the standard one for boost). I guess power would be very similar, capacity is similar too so fuel should be pretty close. Also, what is the LD28 head like? Would it be possible to put l28 valves into it so it flows better? (i assume they are bigger?)

Cool, thanks for the answers. Well, i guess i really wouldn't need the larger sized throttles, but if i were going to spend the money on such a setup i'd like it to go on a decent motor that was making power to 8-8.5k rpm or so. Surprised you think they will support up to 300 rwhp. From my limited experience on ITBs on 4 cylinders, 43mm throttles on a 4cylinder should be good for a little over 200hp. I havent really played with high HP L series yet (only have a near standard L20e in my JDM FairladyZ), but no doubt you know what you are talking about. Thats cool Derek, just putting it out there i would be very willing to pay some decent money for castings - i'm sure others would too. I'm sure with the interest you have received you could make them for profit as part of your business. You'd have to cast your logo into them though! Cheers

Awesome work Derek. Really, really cool. Have a few questions, i hope you can answer them for me. How hard is the CAD-CAM part of the pattern making? I would love to make parts like this, and am reasonably proficient at Solidworks/Inventor, although i have never played around with CAM packages. As i understand it, it is not as easy as just sending the model to the CAM package, and then to the CNC mill? I see you are using 1.495" diameter butterflies. Is there any possibility of putting larger butterflies in for a bit more of a worked-over L series? Say, 1.69-1.77"? I would be very interested in buying a set of non finished castings off you if you ever decide to sell some. I like the performance, sound and style of triple Mikuni setups, however i don't like the tuneabilty, economy and hassle of them. I really like the overall package of your setup. I was considering making some custom ITB's, but went against it as i felt it wouldn't suit the style of the car. I feel yours fit the car perfectly. Robbie