Melted Piston.

With all the cheap Chinese knockoffs around these days... I personally prefer to use a brand that I know, and the extra few $$ for the better hardware, probably not needed but it's a nice touch.

shop around and you'll find the SCATs for maybe 300/320 delivered to your door.

SteveC
 
Stripped the block today.

Pistons 2 & 3:

IMG_2883_zps41c7b509.jpg


other side:

IMG_2884_zpsd6463b1a.jpg


bore - most of the markings look like aluminum from the piston - hopefully the bore will clean up with 1st OS

IMG_2889_zps95e2917b.jpg


IMG_2889a_zpsb0723ff4.jpg


con rod bearings, don't look bad to me

IMG_2886_zps63769529.jpg


IMG_2887_zps946b894c.jpg


IMG_2888_zps66044cee.jpg


mains - look OK also - no signs of damage from particles/piston debris. No real debris in the oil either, so I think the oil pump is probably OK also.

IMG_2882_zpsbe0ce697.jpg


deck

IMG_2891_zpsf6079086.jpg


found this is the pan:

IMG_2885_zps64e4e701.jpg


looks like (a bent) one of the spring retainers on a Bosch EFI connector to me.
 
I'll be taking the opportunity to replace the T/O bearing that was water damaged 2 years ago when the X was partially submerged in one of our annual floods.

I'll do the nylon lever bush too this time

IMG_2881_zps71a7814c.jpg


clutch functions fine & disc has plenty of life - but I'll probably just do it all - Murphy's Law

IMG_2880_zps52c37c64.jpg
 
Now that you've sourced the crank and cylinder head for your build, the next challenge is finding suitable pistons that will give you an increase in static compression over the standard 1580 pistons... which you can buy almost anywhere (1580 8v might even be a current production engine in some countries)

I've found that a Mahle 0872 works. Trouble is I bought up on them a few years back and probably have the bulk of the worlds supply, not kidding, I had about 15 sets at one stage...down to maybe 10 now.

I have very limited oversizes though, as I bought them all for my racing programme...and 86.8 is the size that suited my needs best, as I end up with 1598cc , under the 1600cc capacity limit of the class I'm building for.

I have a bit of a write up on 1600's here if you haven't seen it already

http://www.turbo124.com/forum/viewtopic.php?f=10&t=7402

So I honestly only have 86.8 and 87.0 sizes in this piston type ...the 86.8's I'm hanging onto for my under 1600 engines...

87.0 is a particularly nice size though, as total seal rings are available in 86.0, 86.5 and yep 87.0 ... so it opens up nice ring options... and your at 1602 cc's

Another workable option would be having pistons made, and this would open up more ring options... and let you get whatever piston size you wanted.

The 1580 standard ring pack is a nice option, thinner rings, (1.5/1.75/3 whereas standard is 1.5/2/4) and even a moly coated options from the factory...

Matt at midwest has Wieseco pistons made with an increased compression height and (handed) flycuts to suit oversized inlet valves, wouldn't be too hard to copy his design exactly, but drop the CH down to maybe 33.5mm ...run it past him as I think he could sell a few sets given all the interest in stroking to 1600.

Only downside is your talking around the $800 (maybe plus) dollar mark though for a set of custom pistons and rings .. that's pushing close to double what a set of cast pistons would cost you at around the $500 mark... your choice though as it's your money and your build.

SteveC
 
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Crank & BV head are on order with GTTurbo :).

Thank you Steve, for the detailed feedback.

I read through the linked thread, much good info there!

I'm curious if you have any pics of pistons that have been recut for the bigger valves. I'm very much a visual learner, it helps me to be able to visualize the steps of build process.

I'll send Matt an email about the pistons. I'm leaning towards a proven/ already tested setup - the Mahle 0872 with new cuts for the larger valves sounds like a good approach. I'll be talking with the machinist tomorrow, so I'll get his input once he has looked at the bores, etc.
 
No nice clear pictures to hand, sorry... but from memory I had the pistons that I sold RossH re-flycut for him, maybe he has a picture from his build that shows it clearly??

It's not that big of a deal really, but without doing this step your going to bend a valve for sure (like varvelle did!!)

Any good machinist with a piston vice for his milling machine will be able to do the job. It's simply a case of removing the rings (as the piston vice will use the ring grooves to hold and steady the piston) setting the vice up for the 18 degree tilt that the pockets are cut at, setting his cutting tool at the desired radius and making a cut down to the original flycut depth ... but only on ONE valve pocket per piston... which means two pistons get the right pocket machined, and two get the left done... trickiest part for the machinist is getting a nice radius at the bottom of the cut, you don't want a sharp edge here.

Going from memory.... I recall the original flycut being approx 19/20 mm in radius, I think the number was 22mm radius for the new cut ... (I'll have it written down somewhere) again from memory it was about $100 to have done

You need approx 2mm min radial clearance around your new 39.5 valves.
The flycut does deepen the pocket a little, at the deep end of the cut about another mm in depth, which works well for cams with a high LATDC too.

SteveC
 
993TT / 928GTS. The only difference between the applications is the position of the balance tube. Used with 330mm rotors.

PA010321.jpg


PA010322.jpg


You can PM me if you want, I'm trying to pass it on to a Volvo owner first, since there are custom brackets that go with....
 
fiatfactory said:
The flycut does deepen the pocket a little, at the deep end of the cut about another mm in depth, which works well for cams with a high LATDC too.

SteveC
Click to expand...

Forgot about this part - I was planning on using the 35/75 cam I already have, with the shaved cam box from Bayless. Is there any compelling reason to consider a more aggressive cam? I noted that peteX19 is planning on using the 40/80 cam.
 
Couple of questions for those who may have experience:

1) Does using a EU Tipo head require using the 1300 or 1500 belt tensioner?

2) Are Scat 2-5050-1915-1000-866 rods the correct dimensions for our motor? The listing I have found says for Punto. The vendor has no clue.

Fiat, Punto GT, Scat 4340 Forged Steel, H-Beam Connecting Rods 5.050" Length or (128.27mm), 3/8" ARP 2000 Cap Screw Rod Bolts

H-Beam Rod Specs
Rod Length: 5.050"
Rod Journal: 1.915"
Wrist Pin: .866"

alternative specs from a non-scat h-beam listing that specifies X1/9:

A set of 4 rods
Rods big bore: 48.6 mm
Rod small bore: 22 mm
Length: 5.060"
B.E Width: 25.4 mm
Weight: 545g
 
Hussein,

scat rods PART # 2-5050-1915-1000-866

ARP 209-2801- flywheel bolts

ARP 203-5403 - Main stud kit

ARP 207-4201 - M12 head stud kit, haven't used these myself but dimensionally they look about right

M10 head stud kit possibly toyota 4age, not 100% sure, again haven't tried these yet.

there is a seller on ebay? who lists an arp kit for uno turbo and punto ... but gives no arp reference number.

Make a water pump gasket, you can buy gasket paper in various thicknesses.

1500 tensioner bearing.

SteveC
 
Thank you, Steve.

Ordered the rods, Main & Flywheel hardware/bolt kits

The head bolts are two different lengths, I had already ordered new ones from Bayless, so I'll just use them.
 
fiatfactory said:
No nice clear pictures to hand, sorry... but from memory I had the pistons that I sold RossH re-flycut for him, maybe he has a picture from his build that shows it clearly??
Click to expand...

Hi Steve!

Yeah...been kicking myself for not photographing the engine part of my re-build and restoration properly :mallet:

Should have made way better use of the camera than I did, so sorry to not be able to chip in with the appropriate photo here.
 
So, reading a little through the ultimate build, it would behove me to up the exhaust valve OD in the Tipo head from 31 to 33mm. As I understand it, I can use standard 1500cc exhaust valves and just have the seats recut, is that correct? I'll buy new valves as I want to keep my old shaved head intact.

33mm x 8 x 108.5 Fiat P/N 5973129 (1500 cc standard exhaust valve)

EDIT: ordered the valves from Obert while I was there :)
 
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No, I don't know yet. I haven't checked the injection harness or injectors. Oil starvation is a possibility, but the bearings really don't show any indication of that sort of mechanical failure. I had previously overheated the motor from cooling system issues, so that may also have compromised the pistons/bores.

I'm hoping I can find something definitive. I hate not having an answer.
 
0872 Pistons arrived safely from Australia today - thank you Steve!

IMG_2938_zps86444263.jpg


IMG_2937_zps7235b5d7.jpg


crank & head should be here in a week or so, then I can get hopefully get moving on it...
 
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Scat rods & ARP hardware arrived today. Rods feel pretty heavy, considering how small they are :( I'd say at least 1-1.25lbs each. I'll weigh them at the machine shop.

IMG_2950_zps41a2790d.jpg


cleaned up & painted the clutch release arm & replaced the nylon bush. Used copper paste inside the fork, to prevent it seizing on the shaft - I had to use oxy/acetylene to get it off.

IMG_2944_zpse943d1c5.jpg
 
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