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Guidance and Updated l28e build


918datsunz

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So I'm just making sure I'm going down the right road before I continue ordering all my parts. Things I'm looking for in my build an easily streetable, good sounding cam, and quick response. I would love it to be touge style great handling and quick in and out of corners. So motor parts wise I have order all my cam components from schnider. I purchased the stage three cam kit comes with everything rockers, springs, etc. Advertised at a lift of 460 duration int 270 exh 280 supposed to be good from 2500 to 6600 rpm. Next i plan on ordering the dome top style su carbs with a rebuild kit and intake. I plan to bore the pistons over .40, get as much ported and polished as possible, h beam connecting rods, fidanza lightweight flywheel, and all arp bolts. Clutch kit rated at 300hp/300tq, r200 rear end. coilovers and rubber suspension bushing kit????? Tips pointers please I'm pretty sure my set up will work just looking for advice from the experts :) thanks for reading.

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Mikunis are the price of gold lmao and the su's seem to be the best budget bet. Yea I was really wondering if I would need the rods so thanks for that. And will higher lift be ok with su's? If not I'd prefer get something compatible with them? But if so I would for sure rather have the higher lift cam. They have another close to the same specs rated at 480 270/270? And then some even higher if that would be advised?

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Another one at 495 290/290 rougher idle 3500 to 7000 rpm but it recommends either triple carbs, aftermarket efi, or four barrel conversion. But to be honest I would love the rougher lopey cammed monster sound I just want to know if it will handle it safely. As I plan to keep the car and have everything professionally built.

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Yea the cam kit comes with springs, retainers, lash pads and all except the lash pads won't be the right size as you said. I may keep the cam I had already picked out. A lot of people I've seen use a grind close to the cam I had already ordered So I'm thinking it may be my best bet.

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If you ordered a full set from Schneider the lash pads they supply should be correct.. they assume the head is to spec so they send you a lash pad that is correct to suit the cam grind they do...

Don't ignore the rockers.... if you recondition yours over new that may throw the lash pad number off a little... either way you wanna check the wipe pattern once installed to be sure....

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    Sus don't have accel pumps on their carbs.

 

SUs don't need an accelerator pump because of how they work. When the throttle is suddenly opened, full intake vacuum is applied to the venturi formed by the carb body and the slide. The slide begins to lift from the vacuum applied above it, but is slowed by the damper oil used. It's sort of a shock absorber that slows sudden opening of the slide. The increase of vacuum at the venturi draws in more fuel but, as the slide is slower to lift and add more air, the mixture is richer. Bloody marvelous design. 

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The stage III cam may be a little large for what you are doing, unless it's going to be an autocross or track day car. The stage II kit is probably more in line with your build.

 

If you want to keep the SU's, send them to Rebello and have them bored. Mike Yoes has been doing them for years and they work really well on larger engines.

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For your application, don't bother with even opening the engine...just swap the cam kit on and run it.

 

The stock bottom end, properly fueled and timed, is perfectly happy at 450 crank HP, and up to 7200RPM. There is no reason to change things until that point. Although, I do usually put in a set of ARP rod bolts just for peace of mind-rod bolts are the first thing to break.

 

Even at 150,000 miles, I've run stock junkyard longblocks racing at 300+HP for literally 24 hours at a time, just bolt the intake, exhaust, turbo on, time them and send the driver onto the track. One of the street cars has 288,000 miles on it and just puffs a slight bit of blue smoke on startup, needs a set of valve stem seals these days. Been making 300+ HP from it for 8 years now.

 

The stock SU's in good condition will take a stock-headed L28 to 7000RPM all day, with no issues, and will fuel up to 250HP with SCCA ITS legal mods (no boring, no small shafts, no roller bearings, etc) and the flat-top carbs, if you can get a set in good condition, are much better than the roundtops-the problem is getting a set in good condition, since so many people think they're trash, they get treated like trash and most sets are junk these days.

 

The Schneider cam kit will be fine for a daily driver-and that stage 2 kit will be about as big as you can run on a stock engine without sacrificing drivability.

 

The Stage 3 kit won't gain you anything other than stinky idle, crap fuel economy, and a choppy idle sound...you won't pick up power with it without spending a lot more on supporting components.

 

Exactly which L28 do you have? What head casting/block casting/intake/exhaust do you have to work with?

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I'll get all the cast numbers tomorrow and let you know I had them all written down somewhere but seem to have misplaced them. I know for intake I'm ordering an n33 with dome tops. And exhaust I'm getting two 3-1 headers to run my side pipes. I'm also ordering the .40 over flat top pistons. So you guys would advise the 480 274/274 or the 460 270/280? Because there shipping the cam kit out Monday or Tuesday and I want to get the most bang for my buck. I feel as if I'm doing a decent build. What would I need to support the larger cam? I would love to get 250bhp or at least close. Kinda my goal really. At this time I'm just trying to order everything needed to build an engine of that capability. Also that way when I pull the motor everything is ready to install and I won't be pulling the same things apart to add new mods.

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You'll be lucky to make 180HP with the cam, intake, and bore...at the crank-not at the wheels. Stock is 150HP at the crank. Either cam will do, because both cams are going to be limited by the stock, unported cylinder head.

 

No head work, no horsepower. That's how it works. The 0.040" bore won't help with torque, horsepower, or otherwise-the N33 intake is a good carb intake, but is worth 3-4 HP over the E88 casting. The headers will probably actually hurt you some going with side pipes, a properly designed and built 3 into 2 into 1 with a full exhaust will do better.

 

The N42 blocks have 10cc dished pistons to match the open-chamber head-you will work out to about 8.5:1 compression. Shaving the head approximately 1mm will bring you to 9.5:1, which is as high as you can go on pump fuel IF you run the 275-280* cam. A stock cam will not tolerate it.

 

For a street performance L28, the N47 head is somewhat limited, but workable-the exhaust ports with the round liners will do about 138CFM when properly blended into the liner and the valve job is cut correctly. That's enough.

 

The intake port can be pushed up quite a bit, 200CFM should be easily gotten by any decent head porter.

 

Remember-those ITS L24's make 250HP at the crank, and they are "stock"...down to the cam lift and duration. Lobe profiles can change, but duration and lift have to be the same. No head porting, must run stock exhaust manifold, must run SU's and stock intake castings. They also cost multiple tens of thousands from the engine builders who can wring that kind of power from a "stock" engine. Budget 12-18K for one of those...

 

Doing it with the L28, with no rules on "stock" will bring that cost down to about 3500$. The first 2200$ will go to the guy doing the head/cam/valve job though, the rest is just to scrub up the block and get good bearings, rod bolts, and rings into it...

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Oh wow lol I've been following some of the wrong forums then. A lot of the guys are claiming 200-220 with around the same build and larger valves. And I will be having the head ported would you recommend a different cast head? And I'm swapping in some flat top pistons for the better ratio. Would it even be worth it on the over bore or should I just use stock size? My friend runs a machine shop down here so I get all the work done for close to free. I'm thinking I'll have about 1500 in the motor. Maybe like 2500-3500 in the car finished.

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The su setup will be roughly 500 finished just for the megasquirt ecu is like 899 plus shipping I've looked into a few different options and I think for my budget I'm picking up a set of dome top she's on an n33 intake for 300 shipped them just rebuild, bore, and tune them.

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A full megasquirt install is about 800 bucks. It's what you'll spend to get a set of SUs, so it's personal preference at this level.

 

There are a lot of folks who seem to think it's easy to make N/A power...it isn't hard but it requires head porting and matching parts properly. Be conservative, match parts, and you can make 180hp pretty easy. 200 hp and up requires head porting, the stock fuel injection intakes will start choking the engine at 5500rpm. Not lack of air, just air speed too high in the ports.

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I'd would prefer to go carberated and I am having the head ported. I ordered the 460 270/280 cam kit. I plan on running the n33 intake, su carbs, with the n47 head, n42 block swapped out with flat top pistons, and potentially over bored. And maybe some more light mods.

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