Ozdat Engine Design Utility Update

[thehelix112]

Guys,

 

Been fielding a few requests for updates to my engine design utility that ozdat has graciously hosted for almost 5 years now: http://www.ozdat.com/ozdatonline/enginedesign/

 

I thought I'd put the call out to anyone/everyone, are there engines you want to see in the utility? Or any new features that would be useful etc?

If you have engine specs that you'd like in there, it'd really help me out if you added them to the utility yourself by doing the following:

 

Click the Add button next to the component you wish to add (block, crank, rods etc), and follow the prompts for the data it requests.

Set 0 for anything you don't know.

After adding all the components, add an engine for it. There is unfortunately no easy way to link engines to their other components so I'll have to handle this bit.

Click the Export button at the bottom of the page.

Copy and paste the text that appears in the text field at the very bottom.

Email it to me: david _ andrews112 at yahoo dot com dot au.

 

Many thanks,

 

Dave

[dan5138]

I would like to see the Maxima N47 head added or MN47 as some refer to it.

 

Combustion chamber CC: 39

Intake valve: Don't know exact specs, but slightly smaller than L28 intakes

Exhaust valve: same as the Z heads.

 

Edit: Also want to thank your for making the engine design utility. It is extremely useful for brainstorming and making a parts list for building engines.

[NZeder]

You want to fix the L20a settings they have been wrong for years

 

Pre 79 L20a have 133mm rods and post 79 L20a and the L20et have 135mm on a smaller journal with the smaller 19mm little end. ie same as the US L24e Maxima engine on the little and big ends but 135mm is the length for these post 79 engines.

 

Also the pre 79's also have 9mm rod bolts - well this is the case on the 4 sets I have seen/sold over the years (basically the pre 1979 uses L24 rods if you like ie same length, big and little ends etc)

 

The block height of the L20a is the same as the other L6 ie L24/26/28. Also the Pre 79's have 40.1mm compression height and the post 79 have the more normal L6 38.1mm compression height. 78mm bore and 69.7mm stroke to make 1998cc.

 

Hope this helps.

[thehelix112]

Thanks guys. Sorry for the bad info, will update soon,

 

Dave

[Daeron]

This calculator is the absolute BEST, and although I think I have thanked you in the distant past, Thanks again!! I always share the link, but never without recommending that all real hard parts be measured when choosing/purchasing components. Just a standard type disclaimer.

 

The L20A info is the only real problem I have ever seen with it, and as mentioned above, more selection of heads (although it IS easy to sub in your own CC volume figures) and possibly a wider variety of pistons and rods that may be relevant in certain sizes... But THAT is a project that can easily get rather out of hand, so I can see why you might want to keep the "noise" down to a certain level. All this is speculation; my bet is that adding much more by way of piston/rod selection to the dropdowns, you start losing simplicity through complexity.. Feature Creep.

 

Maybe having a link to a page with verified figures for a broader selection of various manufacturer, OEM rod and piston specs? Just for reference, so the user could plug in these values. That puts the data there (if you have the resources to collect it.)

 

I don't have any tables like that bookmarked or otherwise handy, but i know they have come up in several threads. If you are interested in expanding this aspect, and no one else chimes in, I'll start digging through my subscription list and find some tasty morsels.

[thehelix112]

daeron,

 

that sounds great. I'll likely add a filtering option to it and just put all the data in. That way you can choose to use the subsets of the data you want. Any/all links to said morsels are hugely appreciated,

 

dave

[NZeder]

Dave, I think over the years many have used the utility so a thanks to you and the team as ozdat for hosting it. I will have to track down the Japanese website I found that explains the pre 79/post 79 rod differences but given here in NZ we have a number of L20a and L20et (and I have owned or in the family we have owned) a few of each I can confirm there are 133mm rods and 135mm rods I have never seen 128mm rods on any L6

 

I did at one point also see a guy in Japan use the 135mm rods offset bush the little end from the 19mm to more common 21mm and in the that process change the centre to centre length to be 137mm (aka L14 C to C length, well the L14 are 136.7mm if I recall correctly). Not sure what they did on the bottom end - but maybe they also used a LD28 and again offset ground the crank to make a smaller journal for the rod and change the stroke to 85mm or the like.

 

So I guess with enough effort the L20et rods might be of use but I have always passed on them when looking for L20a rods.