L14 Rods WTD

[Gav240z]

I'm after a set of L14 rods for my stroker combo but I also have a couple of questions?

Listed below is a set of rod lengths quoted from member Alan Pugh in another thread I could not reply to that thread as it's part of the old classifieds system.

Rod lengths for L series engines

L13 139.9
L14 133.0
L16 133.0
L18 130.2
L20A 128.0
L20B 145.9 (can not be used on L series 6cyl cranckshaft)
L24 133.0
L26 130.2
L28 130.2

Hope this helps those that want to interchange parts.

My question is if the L16 rods are the same length as the L14 rods then why do people go for the L14 is it the type of piston you can connect to it? I think the L14 uses 8mm bolts and the L16 uses 9mm from what I've been reading can anyone clarify this?

L24 L20A L16 rods should be easy to come by so im wondering what the advantage of a L14 rod would be.

BTW I'll be using custom forged pistons in my application.

[Black Beaut]

Well i see you've been to the sun kissed shores of the United kingdom today so you have the answer, the L14s are 137mm centre-centre hence giving a better rod/stroke ratio with the diesel crank.

Don't know how much luck you'll have getting a set of 6 though, you might be able to source something from Japan though, you're a bit closer than we are

Cheers,
Rob

[Gav240z]

Okay so the measurements i quoted above are incorrect?
L14 rods are actually 137mm as oppose to the L16 rods which are 133mm?

Yes Japan is a good idea I checked yahoo auctions but nothing for early Z's was listed at all.

[Alan Pugh]

Gav,
The L14 rods are 137 not 133. The measurements were taken out of a book and as you can see there is a mistake. I should have gone back and edited the post.

One day when my car is finished, I'll make it to a VicZCar meet and see everyone, but in the mean time as I tell my wife, it's a hobby not a race.

Alan.

[Gav240z]

No problems and thanks for the correction.

Yes I can understand your mentality, I'd love to build my motor tomorrow but I want to explore all my avenue's to build something that I believe will be the best all round NA motor for my 240z.
After all I want it to be worth all the money and time I'm putting into it and I don't want to blow it up or have to pull it apart shortly after it's done just because I've had a change of mind or a better idea.

VicZcar is getting new members all the time but we haven't had a proper meeting in a while hopefully we will soon. Anyway good to hear your interested all the same .

[thehelix112]

gav,

Kick toecutter into organising costa so we can have a turbo vs stroker dyno comparison and maybe some lunch/coffee afterwards.

Dave

[Alan Pugh]

One question while we are talking about stroker engines.
Why forged pistons for a street car that I take it you are going to be driving on a quite regular basis.

[Gav240z]

We are going with forgies because I do plan to take her for a burn once in a while either on a track or AutoX I haven't got into competition yet mainly because I can't afford it on a Uni Student budget but we are also expecting to be able to rev her to 8000rpm or higher so forgies are probably a good idea.

Dave:
Yes good idea I believe Costa was going to organise a weekend away with the Z's somewhere but I haven't had a chance to speak to him about it yet soon soon. I'll also remind him of the dyno shoot out but from your 1/4 mile times i think you'll win but would be interesting to see the power curve that's for sure .

[thehelix112]

Gav,

I don't really see the need for forged pistons in a N/A application, or a low-boost F/I application either. I assume that forged pistons weigh more than cast ones? Obviously they add strength and in a high-power F/I application this gives you more leeway with regards to detonation. Do you imagine detonation will be a problem on your engine? What CR will you be running? What fuel?

Re dyno comparison, will be interesting indeed.

Dave

[Gav240z]

CR could be as high as 11:1 it's what Costa my engine builder/expert has recommended i go with. I have to really sit down with him anyway to go over exactly what rod combo were going to use and what piston specs we should use. I'm not even sure if he's heard of using L14 rods before i know he's running L20 rods in his Z.

Fuel will probably be Optimax/BP Ultimate/Synergy In my personal experience I've found BP Ultimate to be the best fuel in my Z atm however it all comes down to where they get there batch and each individual station not to mention a problem I had a shell once which has left a sour taste in my mouth ever since and I try to avoid them as much as possible.

[Alan Pugh]

Gav,
You are realy in a typical catch 22 situation here, and I will stress at this point this is purely my opinion learnt over time, and a lot of wasted money and perfectly good equipment.

Do you want an engine (car) that will rev nicely up to and past 8000 rpm and still be making power, or do you want to drive it on the street. You need to worry about a lot more things than forged pistons, before you outlay any of those hard come by dollars.

Alan.

[Gav240z]

I understand where you are coming from and can appreciate what your trying to get across to me. I have given these things alot of thought and I feel that my Z will end up being more of a weekend warrior fun car than a street car. I will eventually end up with another car that I can drive on a daily basis not sure what it will be yet maybe a stock 240z (Just can't see myself in other cars).

I will discuss with my engine assistant ( I don't say builder because I'd like to have a big part in the process myself) about forged pistons if they are required and why etc..

Cheers.

[thehelix112]

I have a solution. Power without revs and adjustable from daily drivable to track beast. Don't fight it, its natural.

Dave

[Gav240z]

your talking about Turbo Charging that's blasphemy hahahaha.

[nixcars]

Hi Gav,

I'm currently going through this process myself & found that the best combo is L14 rods & L28 crank. I don't think you can use the L14's with the LD28, the throw is too long for this rod & I dont beleive you can get a piston with the correct pin height to match this set up. If you could get pistons with the correct pin height they would have to be custom forged & you'll be looking at $1500 PLUS...
If you're set in using the LD28 crank, you'll have to go for the L6 L20A rods & get a set of VG30E or VG30ET pistons (these are available in aftermarket forged design). Again, I don't see the need for forgies as the genuine Nissan pistons are very reliable, after all, the turbo piston is only cast & the VG30ET engine had 155KW on 6psi boost & they can handle double that no worries.

The 2 engines I'm building at the moment are both with L14 rods & L28 cranks, but in one I'm using VG30ET pistons & the other with SR20DETpistons. These both have a slight dish so comp will be around 9.5 & 10:1 with the closed chamber E88 head.
If I wanted 11:1 then I'd go with the VG30E flat top.

Just something to consider Gav.

P.S. L14 rods are very rare & expensive here in Australia (try $600 +), but you have a better chance in the UK.

[nixcars]

Oh, btw, there are 2 types of L20A rods, one set is compatible to the L24/L26/L28 crank, these are actually 135mm long & the others have a much smaller jounal & stem, I wouldn't recommend these. ( These might be the 128mm type that Alan is refering to).

Nick.