I was racing at the drags last sunday, and there was a bloke there with an FJ20et powered vauxhall chevette hatch. I got yarning to him. He's put LOTS of R&D (and money!) into building the car. (It runs 10.9's)
He was saying that he began building it years ago, and nowdays more cuold be done with the SR. (There was an SR powered altered there that was crazy fast)
So, he said the next mod he had planned was to have a thick head spacer plate made, and get the bores sleeved to eliminate the lip where the plate met the factory deck face, and run longer (custom) rods with the stock crank and FJ pistons. (Id say he runs forgies, since he runs over 2 bar)The idea of course being to reduce rod angularity, and generate more torque.

Now this got me to thinking. how about doing this to an A series?
D is forever posting up threads with engine building ideas out of left feild, to get a bit more go from our beloved antiquated datto engines. So theoretically, you could do this to an A15, and use E15 rods? plus with a taller block, it would increase the options for pistons. (Since the A15 has quite a short piston)

What do you reckon?

Bam yes! that's a great idea

Too many Diesels Bart! Did my text about e15 rods get you thinking?

Long rod won't increase torque. In fact a short rod has a better leverage ratio on the crank than a long one.

However, a long rod will decrease your instantaneous piston speed/piston G's, meaning the engine will stay in the power band slightly longer (and also slightly reduce stress/friction on the pistons). Going from a 133mm A rod to a 140.64mm E rod wont make enough of a difference (1.62 > 1.71) to warrant the work I'd think (read an article a while back stating you need at least a .1 change in rod/stroke ratio to warrant a measurable change).

If you were to do it I would put a 25-30mm block extender on it, bore it 79mm to deshroud the valves and run some 160ish mm rods = 1.95 R/S. Only really worth it for a mega high revving n/a motor though.

Yes Bart, it is a great idea, I went through this about a year ago when designing my new motor, I asked alot of people alot of questions about it and the common denominator of replies was the difference between thermal expansion of the disimilar metals was an unknown, i.e the A-series cast iron block and the spacer plate made out of similar material (but not quite the same) all 'glued' together with a head gasket in there.

The main factor is most of the heat in a motor is at the top of the stroke due to the ignition, and this is where all of the alternate mods are.

I know where you are going with this idea.

There is another way of getting a 'massive' capacity A-series....keep researching, keep thinking.

a lot simpiler than some of D's creations too

if spacer or decompression plates can be used in turbo engines- i dont really see how this differs except for the piston possibly traveling over the join in the block and the plate. the ring might catch on this join.

By sleving the block and spacer into one sleave, this would create one combustion chamber however, removing the risk of ring catching or combustion wrecking the seal of gaskets.

Funny that Im accused of going left of field :)))

However these ideas are already in the past if you look back at my earlier posts.

Posted on: 2008/2/18 13:22 more than 2 years ago.
http://datsun1200.com/modules/newbb/v ... id=193428#forumpost193428


Quote:

However Gary is spot on as always and heat expansion rates are the biggest hurdle.
You need perhaps slicing another A series block for the top section so it all has the
same material composition and then a master welder to put it together.


Also the use of e15 conrods was an idea I pondered about since 2003/4 when I asked the question if e15et pistons and rods could be made to fit an A15. In 2005/6 I found the e15et rods could be used for a stroker when looking at rods for 40mm crankpins to increase stroke through offset grinding a15 crankpins, Doctor Feral kindly posted a pic of the e15et rods and I fell in love with them ever since. Especially after reading of their reputation in Exa forums when prepped for more strength. However Bike rods are very cheap now in wrecks, weigh about 100gsm less in most cases and interest me to no end.

Ive gotten more left field as I get itchy mainly due to seen so many billet parts advertised for every other engine under the sun except our beloved A.

My last crazy A series idea before recently was the full wet sleeve application :)
Wacked I know but the renault C series block is almost like our Nissan A series is and
can handle 50psi and over 400hp with lesser ports.
Yet the biggest surprise is that the original engine the C series is based on is the
Renault Ventoux which first appeared in 1947 beating the the Austin A series (1951) and superior to what the poms based their A series from.
Then Nissan improved the Austin design and the Renault saves Nissan from doom.
The original creator is rewarded with survival.

http://datsun1200.com/modules/newbb/v ... id=270265#forumpost270265

http://i120.photobucket.com/albums/o1 ... GTT%20Raider/IMG_0128.jpg

http://www.renault5gtturbo.com/forum/ ... ?f=2&t=7385&view=previous

How about just buying this

Or a group buy of a few

That'll do donkey

http://www.h1v8.com/page/page/1562069.htm

http://www.h1v8.com/page/page/4566006.htm

What brings me and others back to the A series time and time again is its simplicity
Rather than the now cliché S2000, Hayabusa v8 and other complex unobtainium, torquey
simple little pumps that achieve what modern engines do is a reward.

eg,
non pollution SU carbed Topgear turbo a12 = 100kw atw
VS
Stock fuel injected pollution gear everywhere SR20DE = 100hp atw
VS
Mildly worked NA 1900+ cc A series = 100hp atw

Coventry Climax engines did just that: raised deck with liners. The spacer was "glued" to the block with some sort of adhesive.

They did have some sealing problems originally but figured out how to eliminate them. Check out the history of the Hillman Imp engine.

I don't recall any heating problems.

A Mechanic in Kyneton has done this very successfuly with a Chrysler 6 cyl.

The capacity was increased by over 1 liter! It is still going strong after 4 years!