F54 + E30 = ?

[Azon]

Is the combination of hte F54 block with an E30 head any good? As far as I know having smaller chambers the E30 head will give me higher comression, but the flow characteristics are not very good compared to N42 etc. simce the valves are smaller. People are welcome to add any info on the combination or just the characteristics of head.

[lambs]

Is the combination of hte F54 block with an E30 head any good? As far as I know having smaller chambers the E30 head will give me higher comression' date=' but the flow characteristics are not very good compared to N42 etc. simce the valves are smaller. People are welcome to add any info on the combination or just the characteristics of head.[/quote']

 

E30 is only any good if you plan on doing porting, and lot's of it, plus fitting bigger valves. As you say it has small valves, but also has small inlet ports which severely restricts flow. The small combustion chamber wil raise CR, but the small valves, etc will negate any benefit.

 

The E30 head (240K/C210 Skyline) was the head to get when the supply of good E31's started to dry up, but required a lot of work to the ports + bigger valves to take advantage of the CR increase. Of course it also depends on what pistons you are using.

 

A better head to get is an E88 from an R30 Skyline. That head has a similar chamber size to the E30, but bigger ports (same as N42) and valves (although only the 42mm inlet, but that's easily fixed). Same result as E30 head but a lot less work. Could still benefit from a quality port, of course.

 

I have at least a couple of R30 heads in the shed and I must admit to be thinking of a garage sale of some of the 240Z/260Z parts I have lying around.

[JBWetzels]

you could also go for the P90, if you can get your hands on one?

 

but seeing as you have the turbo block already i assume that you did not want to go down that track

[gav240z]

In all honesty I agree with Lambs here, having high compression is ok but really to get any benefit from a motor you need to make it breathe more.

 

I like the N42 heads myself the P90 really needs work to get a higher CR.

[lambs]

I'm really mystified as to why people 'have to have' the P90 head. It's the L28ET head and has the biggest combustion chamber of all the L6 heads. That means to get any decent performance out of it on an NA engine (ie increase CR) you have to do one or a combination of:

 

1. Shave a lot off it - not a good idea on any L-series head

2. Use custom pistons

3. Weld up the combustion chamber (expensive, and a lot of work)

4. Play around with piston deck heights

 

Now some say that the P90 has the best flow in stock form. Well that might be true, but porting is mandatory to improve flow on any L6 head, and I can guarantee that any L6 head can be made to flow as well as a ported P90 head (IOW any L6 head can be ported to achieve the same result), given the same valve size configuration.

 

The advantage of the R30 type E88 head is that it gives a bolt-on CR increase on any L28, not to mention the fact they are much more plentiful than the P90 and cheaper.

[NZeder]

So does anyone know if all F54 have flat-top pistons or is it just the F54/P90 combos that do. Reason I ask is that I have 3x L28's I picked up a while ago (I have not pulled them down yet). 1 is a N42/N42 combo (assume dish pistons) and 2 x F54/N42 combo's I have no idea if these are stock or someone has had a play with them.

[lambs]

So does anyone know if all F54 have flat-top pistons or is it just the F54/P90 combos that do. Reason I ask is that I have 3x L28's I picked up a while ago (I have not pulled them down yet). 1 is a N42/N42 combo (assume dish pistons) and 2 x F54/N42 combo's I have no idea if these are stock or someone has had a play with them.

 

Some F54 blocks came with dished pistons....I came across one many years ago.

[Azon]

So does anyone know what compression these combo will give me(F54 flattop + E30 and dished pistons + E30 )?

[Zeddophile]

there is a program floating around called 'L Engine' which will calculate all these sorts of things - if you can't find it anywhere I can email it to you (Its too big to upload here, max size for zip files is 300kb).....

 

I just plugged those two combos in, and assuming everything is standard L28, besides the head being E30 (although the program only has E31, not E30), flat pistons give around 10.2, and dished gives around 8.56.

[thehelix112]

http://www.ozdat.com/ozdatonline/enginedesign/

 

Little web utility I wrote a while back.

 

You could hang around hybridz.org or another US z forum and chase up a MN47 head. From what I can gather they are a small cc version of a P90 head (kidney shape chambers).

 

Tis what I'd be using if i ever built a screamer N/A engine.

 

Dave

[gav240z]

Hi Dave, nice utility there I take it you set it up using Javascript?

 

I am curious where you got all the values from? I haven't been able to find a resource that gives all those rod lengths like I noticed you had the L14 rod length of 136.6 which is a figure I read somewhere but can't confirm. Can you confirm these values are accurate?

 

I too have been reading Hybridz.org and reading some of those wonderful posts by the members there.

 

I have recently had some set backs with my L31 build and to be honest with everyone here have been considering building an L28 turbo instead.

 

However I'm not ready to give up just yet. Despite the fact that L14 rods are worth $700 - $1000 AUD .

 

FWIW i've seen some N47 heads on Ebay for $50 however I wonder if you can tell me what the difference between an N47 and an MN47 head is? I take it it's named MN47 because it came in the 80's Maxima?

 

Decisions Decisions. :roll:

[gav240z]

Hi Dave, I was playing with your Design Utility and was curious about the rod length of L20A rods?

It says they are 128mm

L26/L28 rods are 130.2 mm

L14 are 136.6mm

L24 are 133.0mm

 

I was always under the impression that L20A rods were not quite as long as L14 rods but longer than L24 rods? Otherwise why would people use these rods over L24 and L28 rods?

[thehelix112]

Gav,

 

Nothing on there is set in stone. I never expected anyone to use it to be honest. I did have a different measurement for the L20A rods, but was informed by a L20AET owner that I was incorrect. Thats all I know sorry.

 

I just surfed around a lot to gather as much information on all the measurements that are in there. Was a few years ago so I'm sorry, I can't remember where I got everything from. As much as possible was from official catalogues though.

 

Yes its all written in Javascript.

 

I'm afraid I haven't bothered to look up the exact specs of the MN47 to see if they are any different to the N47 heads, but my gut tells me they are. If you do come across the specs on hybridz or wherever, let me know and I'll add it to the engine design utility.

 

Dave

[luke_mcmahon85]

Just thought i'd throw my 2 cents in here....

 

the MN47, as far as i can tell, and as the people on zcar.com tended to agree with me a while back, is the same head used on the 80's skyline here (don't ask me what years, some came with e88, some with n47) but the n47 are the MN47 as far as i can tell, and have heart shaped combustion chambers, but smaller than the P90. they are an L24E head and thus have the smaller valves....

 

however this is all heresay, i haven't actually checked, next time i have some time i'll head down to a wrecker and pull one to verify the shape of the cumbustion chambers.....ah, who am i kidding, i'll never get round to that...but i challenge one of you guys to...then we can all rejoice in the plentiful supply of MN47 heads...

[gav240z]

Well i'm thinking of heading down to the wreckers soon to try source some L20A rods and an N42 head and whatever other useful bits I can find.

 

Anyone know a good wrecking yard in Victoria? which is likely to have an L20A 6 cylinder 2.0ltr L-series. Commonly found in the C210 skylines.

 

I honestly don't think the MN47 head is worth all the effort, especially because of the round ports. I know that on Hybridz a very reputable engine builder said they are a good engine head. However I have never seen a set of headers designed for the round port head in Australia? In the US i'm sure they are more common or easy to obtain but most manufactuers cater to the square port heads.

 

A P90 can be welded up so it's higher compression and already has the nice heart shape or kidney shape chamber. Likewise an N42 can be modified to suit. All comes down to budget I guess but I'd say all heads are equal with enough dough thrown at them. :twisted:

 

I've never seen an N47 here, but then again I haven't really been interested till recently. Infact most L28's I've seen have the N42 head.

 

I don't think the early skylines with the L24E would carry the MN47 head. All the ones I've seen are E88 open chamber style.

 

Oh well maybe I should take some pics when I'm at the wrecker yard next time.

 

:wink:

[lambs]

L20A was not sold in any Oz Nissan delivered Skyline and certainly not C210, which came with L24S fitted with E30 head for us. L20A will be grey import only. Ferral errol at Datrats might be able to help.

 

Beats me why anyone would bother importing an American spec head, esp a round ex port head. Certainly no extractors available here to suit, so either custom made, or import those as well. There are plenty of very fast NA Z's in Oz that haven't missed the supposed benefits of that type of head.

 

E88 head from R30 Skyline is the way to go for an NA L6. Bumps the CR without the need for welding (which you should avoid at all costs if you can) and can be made to flow well with a good quality port. Add 44mm inlet valves and you have an excellent performance head. Leave the P90 head for turbo engines.