Small port heads.

[ozconnection]

After I put the closed chamber E88 on my L28, I had discovered a machining error that forced me to take the head back off the engine. I had a mate who desperately wanted one, and for the right price, I sold it to him.

 

Look, the E88 isn't a bad head, and if I can find one, I'd probably get it. I did happen to dyno the N42 head and then the E88 head straight after the swap. There were increases in performance at the top end, from about 3.5K onwards, but it wasn't 'OMFG' type stuff. Considering the money I had spent on the head to get it to that stage, it was a little disappointing. Inlet valves were L28, compression wasn't up by too much and the cam was aftermarket but not huge. Had I put a bigger cam it might have made more power but that statement is hollow because I would've had to have tested the old N42 head with the bigger cam to see the actual difference between the two.

 

The 05L head might be good to try on an L24, or an L24 with an L20 crank in it to make a bit of a 'spinner' if you know what I mean. Good rod/stroke ratio, bumped up compression, small port heads for good gas velocity and a light valve train (small valves) and the right cam make 8K rpm childs play! Run L24 dished pistons and add a turbo for even more fun!!

 

Cheers!

[Tony D]

On all this, there is one consideration to be remembered:

 

05L heads are in essence a 'blank slate' for just about any engine you would build.

 

You can ALWAYS remove material. With an 05L, you aren't welding a head for higher compression, you already have a small chamber---which you can always reshape bigger.

 

You got small ports...which you can always make bigger.

 

You got small valves...which you can always make bigger.

 

When you rationally and dispationately analyze a full-on race build, you will amost always weld up the combution chambers, hog the intake ports, and put in large valve seats. With an 05L, you won't weld that head, meaning you aren't decking the head, meaning you aren't altering the cam-to-crank distance for longest chain life...

 

You will do these things regardless, and the 05L is something that doens't require any welding, and the attendant work and costs involved. I would posit for a full-on build, it would likely be cheaper to build an 05L than any other head out there. That welding/straightening/decking adds expense to the build that otherwise isn't needed when using one of these heads.

 

You blokes got a good head there...I wish I had a few to prove this to unbelievers.

 

And that's all the further I can go on this at the current time!

[ozconnection]

On all this, there is one consideration to be remembered:

 

05L heads are in essence a 'blank slate' for just about any engine you would build.

 

You can ALWAYS remove material. With an 05L, you aren't welding a head for higher compression, you already have a small chamber---which you can always reshape bigger.

 

You got small ports...which you can always make bigger.

 

You got small valves...which you can always make bigger.

 

When you rationally and dispationately analyze a full-on race build, you will amost always weld up the combution chambers, hog the intake ports, and put in large valve seats. With an 05L, you won't weld that head, meaning you aren't decking the head, meaning you aren't altering the cam-to-crank distance for longest chain life...

 

You will do these things regardless, and the 05L is something that doens't require any welding, and the attendant work and costs involved. I would posit for a full-on build, it would likely be cheaper to build an 05L than any other head out there. That welding/straightening/decking adds expense to the build that otherwise isn't needed when using one of these heads.

 

You blokes got a good head there...I wish I had a few to prove this to unbelievers.

 

And that's all the further I can go on this at the current time!

 

Well said Tony. I would bundle the Y70 and 05L into the same basket, the 05L for the purists who don't like round ports with liners. And aren't I lucky, I have both!!

[ozconnection]

Most of you reading this thread are probably wondering by now if I have installed the Y70 head onto my L28 bottom end yet.

 

The answer is 'No, not yet'

 

I've purchased a MS2 setup from a guy who advertised his L28 setup on an Australian forum. I've another friend who's doing some minor alterations to the loom for me ATM. The rest is ready and I'm going to get moving on that project shortly.

 

What's been consuming my time is tuning my current setup. For the head comparison to be fair, I needed to do this. The routine I'm using is a combination between the G Tech Pro unit and the Innovate WBO2 sensor and Logworks....data logging.

I've had this WBO2 sensor for a few years but never bothered to use the logging facility. Access to a laptop was kinda the issue, but it was more a lack of understanding of the virtues of this kind of tuning that was more the point.

'Come on, we're working with everything old skool here, why on earth would I want/need to tune with a computer' was my attitude. Well, wasn't I a silly Billy then.

 

As some sort of 'proof' that things have been moving in the right direction, with nothing more than 'tuning' the carb based on the information that has been recorded, I've dropped my 0-100km/h (0-62 mph) times from 11.43 seconds to a (today's) best of 9.93 seconds. SS 400m was 18.2 seconds, now it's 17.26 seconds and terminal speed was 126.7 kmh now its 133.8 kmh. Like I said, just carb tuning here, based on the printed out data I was able to obtain from my WBO2 sensor et al.

 

Have I finished? No, not yet...this IS fun! How much more I can get out of the engine in its current combo is the million dollar question. There's a limit, obviously, but how close am I?...well closer than before I started all this, that's for sure.

 

Once I'm statisfied that I have the carb tuned well, I might opt to put the MS2 on, then the Y70 head. What really comes next?...I'm not too sure. The original direction was a comparison between the two heads, the N42 and Y70, not between carb and EFI.

 

I'll wait to see what some of you might think about the direction I should take. One thing is for sure, I'll never take for granted the ability of modern computers to help with the tuning of 'old skool' ever again....it's really opened my eyes....

 

Cheers.

[Tony D]

You blokes got a good head there...I wish I had a few to prove this to unbelievers.

 

And that's all the further I can go on this at the current time!

 

Well, looks like I will be in a position to stock up and get 'a few' of those O5L heads... I'm leaving for the Airport in 12 hours for a flight to Sydney.

 

OzConnection...you have e-mail! Now to comb the site for other OZ connections, I may have to drink beer with some of you guys. I only wish I had more prep time to load up on 'that which is a beech to get down under' and pack it in my baggage for personal delivery!

[BRAAP]

Well, looks like I will be in a position to stock up and get 'a few' of those O5L heads... I'm leaving for the Airport in 12 hours for a flight to Sydney.

 

OzConnection...you have e-mail! Now to comb the site for other OZ connections, I may have to drink beer with some of you guys. I only wish I had more prep time to load up on 'that which is a beech to get down under' and pack it in my baggage for personal delivery!

 

Ahem...

 

I hear Tony's return flight is destined for a 1-2 week lay over at KPDX... How convenient...

 

Tony, you like burger an beer right?

[Tony D]

Actually....I'm tight on time and flying back straight to SoCal may not even happen. I MAY have to ship the larger items and make the company pay for my flight to Europe. I have tickets bought for 22 September to attend Spa 6 hours with my family...and it would be nice if work didn't make me miss my 'free ride' there again this year. Last year I was working in Spain...so close...driving distance...but so far when the customer won't release you. And to top it all off, I missed the Nugent Concert in Amsterdam, and Zaragoza Spain because I ended up leaving too early. Now I see no Nugent Concerts at all, not even while I was in Michigan. Dammint!

[kolonelklink87]

I've wanted to bump this thread for a while now because I happen to know some progress has been made in this area which shares significant overlap with the controlling detonation and #5 cooling threads.

I'll let the person in question contribute their reflections on the results and challenges but in a nutshell I believe there was an unexpected complication resulting in detonation. I was throwing around some ideas today and having recently returned from japan can tell you that the y70 cylinder head may have been designed for an entirely different climate to our warm shores...

Thinking on this and looking at some cutaways of an e88 I began to ponder on the purpose of the cooling jacket running above the intake ports... I've heard stories of extreme porters welding these up for extra clearance with no ill effects - this lead me to think: are they for cooling??

here are some thoughts i would like to get some input on....

 

*in the cooler climate of japan to assist with fuel vapourisation having a cooling jacket which, in fact, warms the intake tract/port may be advantageous.

*Since the ports are narrower a greater percentage of intake air comes into closer proximity to the port wall. This represents a greater surface-area/volume scenario - increasing heat transfer to the intake air

*the waterjacket may be larger on the smaller port head (not known)

*this problem could potentially be addressed by using an insulating coating on the port walls

*detonation from pre-heated air may contribute to or exacerbate the 5# issue however is more likely an issue associated with smaller port heads due to SA/V complications

 

here is a photo from one of my cutaways that shows the coolant passage arrangement around one of the intake ports on an early(ish) e88 head. I'd love to hear some feedback on this

 

 

 

-pete

 

[ozconnection]

This is a blast from the past.

 

My N42 bottom end has finally expired. It will be rebuilt but probably not for a while as I need some cash for an O/S trip in June. So what to do?

 

A spare L26 P30 bottom end with 100 thou over slugs is the basis for my new creation. The pistons have a dish on them and are cast. The head I'll be using will be the Y70...still 'wrapped in plastic' from a few years back when this thread began.

Compression with a stock Nissan HG will be a touch over ten to one.

The cam will be an MSA/Schneider Turbo stage 2. I like the 114 degree lobe separation for the torque it can potentially produce in the lower rpm ranges.

The engine is in the build up stage with the block assembled and painted and the head being assembled as we speak.

The N42/N42 will probably taken out this weekend and the new engine slotted in very soon. With the L28 out, I can tidy the bay a little too, just for fun.

I'll keep you guys posted.....

[Tony D]

O/S trip....where to? I'll be back in Japan in May...

[ozconnection]

Hi Tony, going to Serbia.

[Tony D]

Ahhhh! Bringing back more of the clear toasting elixir directly, eh?

[ozconnection]

I've been telling all my friends over the years the virtues of the local brew made from fermented plums. Does a great job of taking away any pain you might be feeling.....lol and doubles as a great octane booster too BTW!!

 

Stocks are low and I need to re-supply!

[ozconnection]

FINALLY... the new engine is in the car and I took it for its maiden voyage today.

 

Problem! The carburetor on this engine is a modified 390cfm Holley mechanical secondary unit. It's waaaaaay too rich at open throttle and I'm seeing 10 to 1 mixtures and even 9.8 on the Innovate WB.

 

Allowing for this, the engine takes snap wot bursts without hesitation or stumbling, just like a vacuum secondary equiped engine. Totally happy with this situation. The same carb on my other engine with the Clifford just totally dies (massive bog) when driven this way.

 

Static timing is 15 degrees ATM, a conservative figure to start with. Total timing is 27 degrees. No vacuum advance just yet (as I want to see how this engine responds first to incremental mechanical increases).

 

Response is excellent but the high stall converter is just killing it (2.5K rpm). Its too loose for efficient street driving. I left it in there because I thought the cam might be too lopy.

 

The Stage two MSA turbo grind is a gem, idled smoothly at 800 rpm and created just over 16 inches of vacuum.

 

The sound this thing makes is unlike any other L Series I've driven...throaty plus. Love it already.

 

Cheers.

 

There's tuning to be done with this engine but I have to say there is potential in it. Can wait to get my hands dirty (again).

[ozconnection]

But surprisingly, the idle is very smooth. You really couldn't tell it isn't a stocker by listening to it, even the idle vacuum is up to 17 inches now with a little bit more tuning.

 

In gear, it runs 13.2 to 1 mixtures and idles at 750rpm. At one point during my adjustments, I had a lean 16.5 to 1 mixture and an idle speed of 550 rpm.

 

The valve gear is a bit noisy atm so it'll need a hot lash adjustment soon but that's easy.

 

I bumped up the timing to 20 degrees static, so total will be 32. I haven't connected the vacuum advance up yet and I might not even do it. I want to test it thoroughly with just the mechanical advance and see how that goes.

 

I'm excited by this combination. I will get out the G-Tech, as soon as I'm satisfied I'm getting close to a good tune, I'll compare it to the figures I had with the old N42/N42 L28 combo. Then maybe a run down WSID...

 

A general question "Who else has a Y70/P30 L26 combo?" Probably some dude in Japan and maybe New Zealand but I doubt the US or even Oz. Interesting.

[Tony D]

Arriving SYD early October... Plan on being in attendance at Bathurst.

I HAVE FROM NOW UNTIL THEN TO ACCUMULATE PARTS AND PACK THEM IN MY BAG HERE IN THE STATES

Mark, get the word out and have the guys PM me here. I should have a great excuse to loiter n SYD for at least a week before returning to New Caledonia.Let's make the best ofit, shall we!

[ozconnection]

Ok, here is some news on that little Y70 head.

 

The old L28 (N42/42) in my Cedric pulled a 17.7 second/128km/h quarter mile last year.

 

Last night at the dragstrip here in Western Sydney, the new L26 in my Cedric pulled a 17.1 second/133km/h quarter mile!

 

What I'm thinking is that the small port head, compression ratio and camshaft made up the difference. (I'll ignore the slight variance in engine capacity)

 

I raced against my mate Dave who has my old N42/N42 in his car now, totally unchanged from when I had it and totally stock, cam/compression/ports etc. Cam is on position one (as it was in my car). He runs a 4 speed manual and dual round top SU's.

 

Last night he pulled a best of 16.9 second/130km/h quarter mile. (my time was 17.7sec/128km/h with the same engine remember?)

 

So what makes his car quicker than mine with the N42/N42? Manual trans? Dual carbs? (He was chirping second AND third gears)

 

And what about the improvement given by the L26 in my car? Especially the times. Not massive I know, but significant in this realm anyway.

 

[Josh280z]

So interested in this information, keep up the good work. Keep feeding our hungry minds.

[ozconnection]

I'm surprised I never bothered to look at the Schneider camshaft web site before.

 

I couldn't believe how many turbo grind camshafts they have listed there. I quickly found the one I have in my white car and realised how mild it is compared to some of the others.

 

I want to explore this 'unconventional' pathway by getting a bigger grind and using another Y70 head on my other cars rebuilt and modified L28 bottom end (the coupe). I have a spare Y70 head so that's easy. I have most everything to do it except the camshaft. I was thinking of using the 292-84-14 grind. A turbo grind. Two steps larger than what I already have in the white car.

 

The coupe currently runs a P90 head with 1mm oversize intake and exhaust Ferrea valves. An "A" grind stock cam. Nothing special at all and the quarter mile times aren't any better than my old N42/42 combo. Both had 8.3 compression. The coupe ran a 16.7/131kmh quarter.

 

The Y70 on a 1.5mm over L28 with VG30DETT 4.5cc dish 'flat tops' will see  a high compression ratio of over 11 to one! Maybe some unshrouding and chamber work could bring this down to 10.5. The white cars L26 runs 10 to one and has zero ping!! That's also with dished pistons! These little chambers are very ping resistant.

 

I've been encouraged to try this because of the success I've had with the setup in the white car. All I think I need in the coupe is a bigger cam for more top end with the Y70. I like a turbo cam because of the mininal valve overlap, docile idle and good manifold vacuum it gives. Important features when running in a heavy car like mine.

 

I'd better hurry up. Parity with the US dollar is falling. Not good. Postage is the killer but. Hmmm.

[Xnke]

If you aren't going turbo, I would not go with a turbo cam. Call Isky and have a chat, or send me a pm and ill give him a ring...I know he has a grind for a similar setup!

 

Minimal overlap is not always a good thing, turbo or not. I would take a closer lobe center and more overlap in a n/a, high compression engine, vs. a wide lobe lobe center, low overlap cam.