Classic Alfa Forums

Good luck with that I hope it all works out for you as the expense and frustration soon rise.

What is the ultimate capacity your is going to end up ?

good to see you're still cracking on with it bert,

i look forward to the machine shop results, keep it coming

Hi Bert, I liked your project, very imaginative,
putting together good bits from different motors,
did you proceed with shaping the pistons skirt?

I seemed to me that the more lateral part of the lower skirt,
it is not structurally important for pistons, so can be safely filed,
but I know, being a first try some worries will be natural

Bob

I'm sorry, no updates on the boxers as I was working other non Alfa projects. Maybe I should look into it coming winter, as a build up motor is a lot safer and compact to store then all the parts, some expensive, here and there.

hi bert! i'm interested in what are you doing because i'm following the same process for the alfa boxer 1.7 16V...
do you think a flat piston (without the cam pattern) will be allright for me? or it can be dangerous?
thank you!

Hi.
In the hope of saving others money............

I tried out this route and found the pistons needed far far too much material taken away.

Also the block needed expensive work as it was skimmed as well as bored.

All money that could have been simply spent on good forged pistons and as they say kept it simple.

I've found some different Wiseco pistons, for KTM, Bore 89, Plug size 21... but idk anything about them, maybe an interesting product: 11.0:1 compression rate, not so thick, both types (flat or with 4 cams pattern)
from 80£ each, i will post the URL if it's not against the forum rules...
mike

Post away chap .it all plays

http://www.ebay.co.uk/itm/Wiseco-Forged ... Swo0JWKSCh
does anybody think this will suit on a 16v?
mike

bert308 wrote:I never realised the extra skirt on the Nissan pistons could be a problem, attached is a pic of the conflict. I guess the pistons should be modified to be like the Alfa pistons.
I also ordered a set of the Max Speeding Rods for the old Datsun Bluebird 1.8 as mentioned earlier, they were suddenly on their site for only $169 so I ordered but then they didn't want to sell for that price and had to pay $239. They will need narrowing on the big end side though. I will take the whole lot to the machine shop soon.

hi, how many mm of gap do you think you need? i mean measuring from the piston pin to the crank, having everything assembled ( like in this photo)
'cause i have found something interesting, but need to know if the piston "tails"are too wide or too near the crankshaft..
thanks for any help!

Gap is Gap i guess, but for a true clearance i'd probably want to see 2 or 3mm all round or more maybe?

can you you show us more specifically where you think your clearance is debatable?

cheers

shrew

Hi everybody,
sorry for the off topic, but I found this:
http://www.steelconrods.co.uk/product_i ... cts_id=193
seems interesting, because I have a 16v boxer

Hi, recently I make a search because I like this project for 1700 8v alfa 33 boxer engine.
I found this, not sure it is correct:

- nissan piston engine KA24DE years 93-98 are the ones Bert was testing,
89mm diameter, 34mm deck height (about 1mm different from alfa original pistons),
they are light and have total height of 68,3mm, so with skirts quite long as alfa original pistons,
but skirts need to be filed at sides to use them in a boxer, so require some work-time; here a recent ebay small price ones:
http://www.ebay.co.uk/itm/PISTON-RING-S ... XQeW5TYkkr

- nissan piston engine KA24DE years 98-04 (someone call them for KA24DE-IV engine),
89mm diameter, 34mm deck height (about 1mm different from alfa original pistons),
probably they also are light and already have no skirts at sides, so may be ready for boxer engine,
but total piston height is 60,8mm, skirts are quite short, so probably not efficient/durable
as previous, a bit more a "racing" type, here a recent ebay small price ones:
http://www.ebay.co.uk/itm/PISTON-RING-S ... xyThVTYQxq
Personally I'd prefer the previous 68,3mm type pistons filed at sides than these,
but modify the skirt can generate some doubt about it is been done all correctly,
probably using these 60,3mm type can give more pace of mind.

- I had doubts that the images of the pistons 98-04 was wrong, but it is not,
it seems they really have that shape, there are similar images in other internet pages:
http://www.alibaba.com/product-detail/A ... 48877.html
http://www.alibaba.com/product-detail/N ... .55.YOlRXI
and also here, but it seams a bit different design:
http://www.ebay.com/itm/98-01-Nissan-Al ... 0885096753

- about the quite short piston height (60,8mm), probably it is not a real problem,
if we compare with more extreme racing solution that have skirts also more short like these for 16v boxer
(they use 32mm deck height pistons and 4mm more longer than original piston rods):
http://www.ebay.it/itm/Alfa-Romeo-Alfa- ... SwpDdVLies

About head gasket, the original one seems a possibility,
to keep the project simple as possible; it remains to solve the 1 mm different deck height,
not sure it can be solved skimming 1.7 standard heads, maybe is better skimming the block,
this will modify a very little the cam phase, ideally it should require expensive adjustable cam pulleys,
so it would be nice find some best price options to get instead 1mm longer sport/racing piston rods.

muggimike wrote:Hi everybody,
sorry for the off topic, but I found this:
http://www.steelconrods.co.uk/product_i ... cts_id=193
seems interesting, because I have a 16v boxer

Forged pistons for the 16v are readily available from Wiseco, see the first link in the first post in this topic.

Excellent post Bobkelso and nice find of the other Nissan pistons, I should have found them first time around. Haven't been here for a while and nice to see an update. Today I went to the shed and searched for the parts...I have the rods I mentioned earlier that are 1mm longer, and they are symmetrical. They have a 2mm wider big end than the Alfa rods, so for testfitting I cut a damaged crank in 2. It seems the Nissan aftermarket rods do clear the Nissan pistons on the Alfa crank. Here is a short movie:
http://www.youtube.com/watch?v=RjN1Z2uZDaw
But don't take my word for it, I guess it is time to put my money where my mouth is and take the stuff to the engine shop to have a block bored to 89mm, and have the big ends of the rods narrowed by 2mm. (I also will bring 2 nice flowed heads that I had fitted with new guides and valves, to have the valve seats recut and a light skim for cleanup) So the 1mm lower Nissan pistons with the 1mm longer Nissan rods should give a good shortblock and I will mount the flowed heads with C&B street cams I have for a nice 8v boxer with good power and manners...

Hi Bert, interesting, so that piston type and that piston rod (symmetrical) seams to mach,
from your video it seams there is enough space also considering 1,5mm more
when adding the nissan bearing, with nothing or at worst very little to file from the skirt..

What I don't know is if the machine shop can machine from 26,8 to 24mm,
together with the nissan rods, also the nissan bearings, because as hobbyist
I can't figure the best way to do it, but I hope it is possible and quite normal for "pro",
may be some particular/professional thick is necessary to hold them during process..

Bit of a thread resurrection here, how did this pan out?
I see there is a Nissan 87mm piston too for the z22 engine