Stroked L24?

[TABrinn]

I'm about to dive into rebuilding my L24. I want to know how much of a differance dropping in an L28 crank would make? (Basically turn into a L26)I'm going to send the E-88 head to Rebello to get worked over, I have tripple 40 DCOE's, MSA headers and dual exhaust.

 

Before you start, I don't intend on getting an an L28 turbo or NA.

[JMortensen]

If you're married to the L24, you might do better at classiczcars.com. You'll catch some flak here for not going with the obvious power gains from the larger engine, and this site originated to promote the idea of engine swaps. As far as the gains to be expected, there is an 8% difference in displacement, so you can expect an 8% gain, all things equal. The L28 will give you a 15% displacement bump. A 3.1 would give you a 22% bump. If you're a numbers matching concourse type of guy you're technically "ruining" the L24 since it won't be stock, so you might consider pulling the L24 and buying an L28, then when you go to sell it or whenever you feel bad about not having the original engine you can reinstall it.

[alexdeprat]

Usually some people like to Stroke the L24 engine, when matching numbers come into place i.e. when the original engine is in the car, and one wants’ to gain a bit more torque, and smother drivability. Sure, is possible I did it on my old 1970, many, many centuries ago, I actually bored my to .20, decent power and drove smoother, if I recall I had more or less the same setup that you have in yours. There is an article in Grassroots motorsport magazine on the topic, I don’t remember the issue# but if you go to their web site, perhaps you'll be able to find something on the subject. Rabello sells a kit for what you want to do, so I think, so you’re in the right track.

 

Good luck,

 

Alex

[alexdeprat]

You'll catch some flak here for not going with the obvious power gains from the larger engine.

 

 

Yea that too:).

[johnc]

FYI... the most powerful normally aspirated L6 engines ever built are still the racing GT2 L24s - at least here in the USA.

[JMortensen]

FYI... the most powerful normally aspirated L6 engines ever built are still the racing GT2 L24s - at least here in the USA.

If they can build the bigger engines to make more power in Japan, they can do the same here. I'm sure the only reason they haven't is because of class rules, and because most of the guys that aren't racing (like the majority of the people here) would rather have a V8 that runs on pump gas than a 15:1 compression L31 that's got a lifespan measured in hours.

[HowlerMonkey]

It's because the limits were on venturi size.

[woldson]

If they can build the bigger engines to make more power in Japan, they can do the same here. I'm sure the only reason they haven't is because of class rules, and because most of the guys that aren't racing (like the majority of the people here) would rather have a V8 that runs on pump gas than a 15:1 compression L31 that's got a lifespan measured in hours.

 

Soon the zx will not only be a parts car:)! Cheers!

[TABrinn]

Here's the link to the Rebello engine Alexdeprat mentioned. http://www.rebelloracing.com/enginebuild.htm

From what I've read here, the HP numbers are a little optimistic but anything over 200HP and I'd be extatic. Besides keeping matching numbers (nobody seems to care anymore) I don't have to go out and scrounge up a new engine. From the sound of the feedback I don't think I could give away this one (would hate so see it scrapped). The 2.8 cranks are fairly easy to come by from all of yall building strokers. Sounds logical enough to me.

 

I'd like to keep the L24 rods for an improved rod ratio. Are there any pistons that would fit? I'll most likely get forged ones regardless but I'm just curious.

 

According to the redneck figure of 1-1.3HP per cubic inch, 146-189HP should be attainabe from the L24, 158-205HP from the L26, 170-221HP for the L28, and 189-245HP for the 3.1 stroker. Does this sound fairly accurate?

[Xnke]

The NON-ideal solution to the L28 crank + L24 rods is the Z22S piston, ITM part number RY6116. unfortunately, it won't fit in a P30 block due to its 87mm diameter, and it has a ~9cc dish. The pin height that you need is 35.5mm, custom forgies are probably the only way here.

[JMortensen]

You can use L24 rods in an L28 with a custom piston and get the same rod ratio, but have an L28. Arizona Z Car used to sell forged L28 pistons that had the pin height setup to use L24 rods, and you can always custom order them.

 

I agree that Rebello's hp numbers are a little optimistic. They're also crank hp numbers, not whp, but there has been a lot of talk about them being optimistic in the past. I don't think 200 whp would be too hard to do with an L24 and keep it relatively streetable but why give up the extra power that you could have? You might try to find an L28 locally, just to see if you can. I expect they'll be coming out of the woodwork.

 

You've never really explained WHY you wouldn't want an L28...

[TABrinn]

Why keep the L24?

Besides keeping matching numbers (nobody seems to care anymore) I don't have to go out and scrounge up a new engine. From the sound of the feedback I don't think I could give away this one (would hate so see it scrapped). The 2.8 cranks are fairly easy to come by from all of yall building strokers. Sounds logical enough to me.

 

Datsuns are pretty rare here in south texas. I have searched all the local junkyards and come up with nothing! I guess the high price for scrap steel is too tempting to keep them around. If I were to go through the hassel and expense of having one shipped, I'd get the big dawg LD28 for a long rod stroker.

[JMortensen]

Datsuns are pretty rare here in south texas. I have searched all the local junkyards and come up with nothing! I guess the high price for scrap steel is too tempting to keep them around. If I were to go through the hassel and expense of having one shipped, I'd get the big dawg LD28 for a long rod stroker.

I'm sure with all the Z clubs in Texas rounding up an L28 shouldn't be too hard at all. You might try a WTB ad here and then try a club based in your area. We have a ton of members from Texas and who knows how many of them have swapped in a V8 or SR or RB and have an L28 sitting in the garage.

 

I would think it would be much harder to find a crank than to find the whole engine.

[blue72]

Even posting a WTB ad on Craigslist has netted results for me in the past. You never know who has what stashed away in your area.

[Austin240Z]

I'm sure with all the Z clubs in Texas rounding up an L28 shouldn't be too hard at all. You might try a WTB ad here and then try a club based in your area. We have a ton of members from Texas and who knows how many of them have swapped in a V8 or SR or RB and have an L28 sitting in the garage.

 

I would think it would be much harder to find a crank than to find the whole engine.

L28's arent that hard to find around here, I have a few, but they're all "fixer uppers" enough to make atleast 2 full motors. There's a 280ZX sitting in my favorite junkyard right now, probably $200-300 for the motor. If i didnt already have enough L28's I'd be picking it up.

 

it is true that the L28's are getting harder to find, especially now with metal prices, but they're still availible.

 

L28ET's on the other hand.... I havent seen one in any Austin junk yards in probably 2 years now.

[jc052685]

Datsuns are pretty rare here in south texas. I have searched all the local junkyards and come up with nothing! I guess the high price for scrap steel is too tempting to keep them around. If I were to go through the hassel and expense of having one shipped, I'd get the big dawg LD28 for a long rod stroker.

 

yeah, not really. Saw 3 in one junk yard on saterday. I have a rebuilt L28 bottom end that only has 1600 Miles I need to sell!!!

[TABrinn]

I'm in South Texas, Corpus Christi to be exact. Much further and I'd be in Mexico! I work 10 hr days 7 days a week, so finding time for much of a road trip is easier said than done!