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Discussion Starter · #1 ·
Ok, bringing up some stuff I've read around, including probetalk. The KL series of engines appears to have a possibility of having great NA power in the lower end, however, it seems that the valves and head and such can't keep up. Mainly, this can be seen from people with ZE's who drop valves past 7000rpms.

So, the question is, boring out the short block, and putting in 12:1 pistons, how much good will it do with the crappy valve work? Like, would I be looking at a max of 50 extra hp from the work?

And perhaps, do you think any shops out there would custom make a new valvetrain for the right amount of money? Discuss, =)
 

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ZE's drop valves due to the ZE springs destroying the ZE valve spring retainers.

The DE valvetrain is quite strong as proven by Matt Maas who made 504whp on his boosted application using it.

As for a custom valvetrain, Interprep offers springs and there is some other company who offers quite expensive Titanium retainers (I forget who).
 

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Which is why I am swapping the springs and retainers off my de to my ze.
 

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Fastest, I think the company you are talking about is Cyborgzero (CZT)? I've been going thru probetalk recently and this struck my interest...

Excerpt from jon93pgt's writeup...

Ferrea- http://www.ferrea.com- Clearly this company has the most experience with aftermarket valvetrain products. They are the largest company and put out VERY nice stuff. For the KL engine, they offer a stainless steel valve, spring, and retainer, and chromoly valvelocks. The spring they use is a double spring. The downside of Ferrea? $$$ The full valvetrain kit listed above runs close to $1000.
Interprep- http://www.interpreptuning.com/- This company clearly has the MOST experience with the KL drivetrain. They have done extensive KL cylinder head R&D and have good products to boot. Alistair at Interprep is a great guy to talk to and will answer all of your questions. They offer products for the KL engine, but I am not too sure of the metals they use and what the specs are on their products.

Paeco- http://www.paeco.com/- I haven't done much research on this company, although the rumor is that they supply oversize valves. If you want to spend the extra money to machine your valveseats, this company will provide the valves. I do not know of the quality of their parts, customer service, etc...

CZT- http://www.cyborgzero.com/- Many know that CZT had some great ideas and good research, but I do not know how many sets they have or currently produce. They currently list a "Stage 1" valvetrain kit which includes titanium retainers and chromoly valvelocks. This is of course, 03 sized, so if you want to use this on your ZE heads, you'll need some 03 springs as well. They also used to supply a titanium spring package as well, which was part of their "Stage 2" package. I guess they do not produce these anymore as they are not listed on the current CZT site. Also, they are currently listing testing on new aftermarket KL cams. This company is cheap, but with a small background, and shortlived life on Probetalk, the customer service or product backing may not be what it is with the larger companies listed above.

These are all companies that manufacture upgraded valvetrain components for our engine, now only if I had the money... And a KLZE... And motivation...
 

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I've been toying with this idea for a while now. There are a few others with the idea as well. From what I've found, a 60 or 80 overbore will work if you stay NA.

60 over will gain about 5 cubic inches. 80 over will gain about 7. If you figure that the stock motor is about 150 ci & makes 164 hp, that's just a little more that 1hp/ci. At that, 80 over might gain 10 hp.

HOWEVER - that is with all things being equal. The higher compression will make up more power. You'll have to run hi-test to compensate. So maybe instead of 1.1 hp/ci you'll be at 1.5 or (YEAH!) the magic 2.0!

Either plan on doing a complete teardown & rebuild of the shortblock, or just do the heads & leave the shortblock alone. But, if you're doing the short block, research the possibility of a stroker. It'll all be custom, but you can add over 20 ci instead of 5 or 7.
If you over bore to 80 over, it makes it easier to unshroud the valves & use the oversize valves.

With the larger displacement, better breathing definitely becomes a factor. That means ZE intake or ported DE along with a larger throttle body.

The engine can make big power (I've run dyno syms to nearly 300 hp & 250 tq) and still stay under 8000 RPM.

Yes, the motor loves to rev. Yes, turbo & S/C are easier. Cost? It's a toss up. Reliability? Depends on how much you spend on the rebuild (rods, bearings, etc.)

If you're looking to "work your way up" so to speak. Get a set of heads, send them out to be ported (or do it yourself.) Then upgrade the valve train. Put them on & see where you're at. Then work on the short block.

So, can you get 50 hp from 12:1 & boring? It would be close, but I'd have to say no. But you could easily get that from a good port job, upgraded valve train, and better cams. An it may not cost you much more (if at all.)

At least, that's what I've discovered researching this.

Regardless, HAVE FUN! IT'S A HOBBY!
 

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Discussion Starter · #10 ·
Thanks for the comments everyone.

Now, how does stroking factor into HP? Like, going from a 2.5L to 3L, while leaving compression and bore the same would do what? Also, what determines the compression of a piston, or should I say, which part of it? The general plan over time is to have the block rebuilt, heads and valvetrain and everything worked on, and go for 350-400whp NA power. Obviously, it's gonna cost a pretty penny, but it's the way I want to go.

Looking around at different things, I see this thing called "Big Bore Sleeving", (http://www.importperformanceparts.net/imports/bigbore_sleeving.html). Is it just a combination of stroking and massively boring?

And one last tid bit. To increase the level of which an engine can rev higher, what should be considered/researched?

track6 said:
I've been toying with this idea for a while now. There are a few others with the idea as well. From what I've found, a 60 or 80 overbore will work if you stay NA.

60 over will gain about 5 cubic inches. 80 over will gain about 7. If you figure that the stock motor is about 150 ci & makes 164 hp, that's just a little more that 1hp/ci. At that, 80 over might gain 10 hp.

HOWEVER - that is with all things being equal. The higher compression will make up more power. You'll have to run hi-test to compensate. So maybe instead of 1.1 hp/ci you'll be at 1.5 or (YEAH!) the magic 2.0!

Either plan on doing a complete teardown & rebuild of the shortblock, or just do the heads & leave the shortblock alone. But, if you're doing the short block, research the possibility of a stroker. It'll all be custom, but you can add over 20 ci instead of 5 or 7.
If you over bore to 80 over, it makes it easier to unshroud the valves & use the oversize valves.

With the larger displacement, better breathing definitely becomes a factor. That means ZE intake or ported DE along with a larger throttle body.

The engine can make big power (I've run dyno syms to nearly 300 hp & 250 tq) and still stay under 8000 RPM.

Yes, the motor loves to rev. Yes, turbo & S/C are easier. Cost? It's a toss up. Reliability? Depends on how much you spend on the rebuild (rods, bearings, etc.)

If you're looking to "work your way up" so to speak. Get a set of heads, send them out to be ported (or do it yourself.) Then upgrade the valve train. Put them on & see where you're at. Then work on the short block.

So, can you get 50 hp from 12:1 & boring? It would be close, but I'd have to say no. But you could easily get that from a good port job, upgraded valve train, and better cams. An it may not cost you much more (if at all.)

At least, that's what I've discovered researching this.

Regardless, HAVE FUN! IT'S A HOBBY!
 

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Stroking the engine increases the "throw" length of the crankshaft. A longer throw means more torque. The down side is that piston speed also increases meaning more stress on the rod.

The stock crank can be machined to add at most .25 of stroke. There are some commonly available Honda rods that fit the "new" rod journal so "all" you need then is custom pistons. The price I got from Ross was about $550 for the set.

Again, if you're doing the work, I'd say go ahead & do the bore as well. With an 80 overbore and a .25 stroke you're at about 2950 cc. Again, in the dyno sym, with that combo, 11.5:1 compression, and a 210 cam with .365 lift, the best I could get was about 325 hp & 250 tq. You're still limited by the displacement.

And, once you get that far, you will need aftermarket engine management.

As far as compression, it's a factor of piston height, dome size, how far the piston is below the top of the cylinder, and the stroke.

Good luck!

Tim
 

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Discussion Starter · #12 ·
So is there any other way to get more displacement out of the engine? Any way to get a new crank and extend it or anything?

(Edit: And where is this dyno sim that you have? =))
 

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When others here have looked into or done strokers, it seems the only real option is to have the crank "reground." What that amounts to is removing material from the rod journal to move the center of the journal out. That means that the new rod will have to have a smaller bearing than the existing.

Don't quote me, but I think the factory journal is 2.08 & the Honda journal is 1.77. Figuring in that you still need the journal to be round, the gain is maxxed at .25. That would change the stroke from 2.92 to 3.17. If your crank guy is good & you go with 20 under bearings for the Honda (taking it to 1.75) you may be able to get a full .3. But, you start getting into block clearance issues. The local shop here wanted $300 to grind the crank & $150 to bore the block. I found a Honda rod that was 1.77 rod journal, 5.5 inches long, and only .02 inches thinner than the stock & made by Eagle. About $100 each but nice & strong. Oh - as the stroke increases, you change the rod ratio based on rod length. The stock rod is 5.42. Rod ratio has to do with the angle of the rod at the piston and how hard the piston is pushed sideways in the bore.

Basically, increasing bore and/or stroke is the only way to get more displacement. I've read rumors of going to a full 100 over, but I would imagine the walls are getting real thin at that point. That's where sleeving comes in but I didn't want to go there.

The dyno sim is a freebie trial download. Engine Analyzer Pro. I had to build the specs for the intake, exhaust, heads, etc. I built everything then ran "stock" sims to make sure I was close before I started modding the sim.
The trial is only good for 10 days but I have an older PC that I don't have anything else on. I loaded Norton "GOBACK". Then I load the sim, use it for 10 days, then GOBACK & reload. The package I'm using is over $400 to purchase & I can't justify the price for recreational use.

Tim
 

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:urg:

I just can't fathom putting in all of this work which is generally untested by others and may prove to be unreliable.

For far less money, you could rebuild a stock motor with high quality standard sized parts, forged rods and pistons if you so choose... and maybe even some work in the head. Add some forced induction as most others do, and you will make much more power at a far lower cost than what has been proposed in here. Likewise, should anything need to be replaced, there won't be issues sourcing parts like their would be with a highly modified engine block and head.

I understand the allure of a high compression, bored and stroked N/A motor, but when it comes down to it, there's a reason that practically no one goes that route: cost vs. reward.
 

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You are probably right as far as the cost vs power. That said, not everyone likes the driveability of a turbo car. They have to be properly designed to avoid lag, maintain boost, & be reliable.
Besides, if you have 200+ ft/lbs of torque from 2500 to 6500 RPM in a 2700 pound car, you'll be happy. The stroker sim does. Yes, the turbo can do more, but do you REALLY need it? For a street driven car?

And, if you compare apples to apples where you have to pay someone to install things, the cost is a lot closer. You can't take the case where someone scrounged all the cheapest Ebay parts & put them on in their backyard for $800 & say that's what it costs to do a turbo. Not across the board.

Does anyone sell a COMPLETE turbo kit for less than $2500? For that matter, a supercharger kit? I'll be honest, when it comes to forced induction, I lean more toward the Eaton/roots blowers. They're nearly instant & don't have as many negatives as turbos (namely oiling, heat, and lag.) BUT, they do steal some power to run.

Anyway, it still boils down to chocolate & vanilla. Take your pick but remember that not everyone likes that flavor.

Tim
 

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Discussion Starter · #16 ·
As Tim said, I have my reasons for wanting to go NA. I understand that it would be insanely cheaper to go F/I, but hey, I like to be different.

Back to where we were. I will be sending off the block to get rebuilt by a professional, but I can probably do the valvetrain and cams myself. I'll send the head off also to get ported/polished. With the block, I was thinking of trying that big bore sleeving, they say they can bore up to 3-4mm bigger than what's currently available. Do you know anything about that?
 

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On the software, I've always used Dyno2000, one of the better ones I've come across. :tup:

I remember thinking about boring it to the point that sleeves would be needed. However, in my researching it(over on PT), if I remember correctly, there are lots of problems with sleeving. Do a search on PT, it helped me quite a bit. If i can find the thread i'm talking about, i'll post it up.
 

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Sorry, can't help there. Beyond the concept, I haven't researched it. From what I did read, it amounts to boring the cylinder for all it's worth & then welding a steel sleeve in place to give the larger bore & strength.
I put the numbers in a spreadsheet that I put together for all of this when I was doing the math. At the 3.22 stroke, the difference from the 100 over (2.5mm over stock) that apparently can be done to 160 over (4 mm over) is 6 cubic inches. At the stock stroke it's slightly less.
Again, I think that point of diminishing returns kicks in somewhere. IF the 100 over is legit (a machine shop should be able to tell you) and a typical bore job will get you there (for the first 25 ci) is it worth the extra to sleeve for an additional 6 ci?

Then again, why not go all out, it's not my money! If I get the chance, I'll put those numbers in the sim & see what shakes out. I would guess something in the 300-330 hp range with peak torque about 250.

I did find that intake makes a huge difference as well. Single plenum vs split plenum, runner length & dimension, etc. I was exploring mounting a Lincoln Town car dual throttle body on the stock ZE intake for the increase breathing needs. What I liked about that TB is that the TB plate axis are vertical. Only one opens at part throttle but both are available for full throttle. That should help to maintain low RPM driveability without choking the engine. The bore of each is 57mm. FWIW.

What I like about the overbore/stroke idea is the torque gain. That's the power you feel. If you want to know what a torque difference is, go drive an an RX-8. Then drive a new Mustang. 6 cylinder. The hp on the RX-8 is about 240 but tq is only 160. The hp on the Mustang is 215 but tq is 240. It makes a difference. Of course, in that comparison the Mustang is 500 pounds slower, but you get the point. If you don't then drive the V8 & you will!

Tim
 

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Discussion Starter · #19 ·
I think considering all of this, I'll probably just bore 80 over and see how it goes. I can attempt to find the highest compression pistions I can, and with a bored out TB, ported and polished head, colt cams, upgraded valvetrain, and bored intake runners from a ZE, I can probably do pretty decent.

When doing the valvetrain, what is there to upgrade besides springs and retainers, that I could do? And with the ZE IM, is there anything special I have to do to it for it to match up to a DE head? (Other than the install issues of vacuum lines and all that.) And on boring, is there more to bore out than the intake runners that would help? (Also, I'm still waiting on the MMI Intake Manifold to see how it runs.)

Thanks for all the advice so far, it's been a great help.
 

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Did you read the cylinder head thread over on Probetalk? It's got some great info re what's available.

http://forums.probetalk.com/showthread.php?t=1701144558

There are valves available that are 1mm larger in addition to the springs & retainers. They also have a better cut for flow. I'd recommend getting the head work done somewhere that can flow bench them & make sure the flow is even.

As far as intake, it is mostly in the runners unless you look to a custom manifold. Again, over on PT look into acid porting. Never did it but some have with success.

More likely than not, the best piston option will be something custom. That doesn't automatically mean big cost. Most places can do custom for less than $100 per piston with rings. Then you can get any compression you want.

Regarding both heads & intake, because of some recent "downsizing" at my company, I've decided to clear out my stuff & focus on paying the house off instead of toys. I had bought nearly everything I needed to start my own engine build. So I have a pair of ZE heads & ZE intake that were for my project if you're interested. Not to high-jack this into a sales pitch, but I thought I'd mention it.

Tim
 
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