Hi-Comp Pistons: 124 Spider

MIGHTY 8 · Post by **MIGHTY 8** » Sat Sep 02, 2006 1:35 pm

Hello everyone,

Reading the previous posts on hotter cams, which I have now ready to install (Vick's 40/80.) I decided to invest as well in higher compression pistons. It seems, from what I read, that the cams alone will not produce their max potential without these accompaning performance pistons. I believe from what I read, that's pretty much the consensus.

Question is, which ones to purchase? I believe IAP sells only the 8.9:1; (+.4), where Vicks sells both these and the bigger 9.1:1; (+.6)

I have an '80 2L, with IAP 4:2:1 headers, and dual Weber 40IDFs.

There is of course, the option of simply installing the cams, and evaluating the results. However, the dilemma here is since it would be my dear mechanic doing the work, in the long run, prudence would say spend the money just once on opening up the engine, and removing/installing both.

Any good comments would be welcome.

Happy Labor Day

racydave · Post by **racydave** » Sat Sep 02, 2006 3:25 pm

It might be a good idea to disassemble the engine and inspect the cylinder condition before ordering pistons. Check all bearings and oil pump. Also it probably would be an opportune time to upgrade factory valve springs. what does your tech say?

Joe Clemente · Post by **Joe Clemente** » Sat Sep 02, 2006 6:11 pm

Check with Bruce's parts or Vick auto and see if they have the 9.8:1 pistons. Those would be better in combination with that other material you've got, make for a nice potent little motor. racydave's right about the rest including uprated valve springs.

IAP springs aren't that great. I would recommend the Croft triples or, if you are on a budget, PBS still sells their spring kits for around $100.

Regards,

Joe

bandit · Post by **bandit** » Sun Sep 03, 2006 4:41 am

or u could use ford pinto engine springs easyer to find but to
be honest with you the stock fiat springs can handle those
cams and should get you by . I would maybe replace the
inner springs for a few bucks .

Daniel

MIGHTY 8 · Post by **MIGHTY 8** » Sun Sep 03, 2006 10:16 am

So go with the 9:8s, huh? Are there any tractability issues between the two, such as there is in the cam world?

Gotta say that when the Webers went in, its hard to leave the rest of the motor stock, and not take advantage of the sleeping potential that's readily available.

Does anybody out there have this type of set-up on their 2L?

lanciahf · Post by **lanciahf** » Sun Sep 03, 2006 4:35 pm

Be Careful 9:8 pistons in a 2L yield around 10.8 to 11.1 compression ratio due to the longer stroke. The 9.8 were originally for a 1.8. I once had a 2L Beta with "9.8" pistons. Great torque and power but Premium fuel was a must and the car always ran towards the hot side. If I had a 1.8 I would use the "9.8" pistons with a 2L head to lower the compression a bit. If I were you I would enjoy the 2L with the 8.9 pistons and just use one of the 40/80 cams for the intake and use a stock cam for the exhaust side.

TURBO124.com has more details on this matter.

see
http://turbo124.com/forum/viewtopic.php ... c&start=15

or

http://turbo124.com/forum/viewtopic.php?t=2013

Joe Clemente · Post by **Joe Clemente** » Mon Sep 04, 2006 2:15 am

Good point about the fuel requirement. We've got access to 94 at the pumps here but it has been the bare minimum I've ever been able to run with compression.

MIGHTY 8 · Post by **MIGHTY 8** » Mon Sep 04, 2006 10:51 am

Ok. So no on the 9:8 now? Mr. Clemente, from reading your previous posts, I thought you were the guru for this stuff!

Just joking, my friend. In all seriousness, with the holiday and all, I haven't been able to call any of the suppliers and ask them directly on their recommendation.

93 Octane is about the highest I've seen around (East Coast.) Is this pretty low for these 9:8 pistons? How about for the 8:9s?

Tractability/Reliability is something that I still aim for. This end result would be for street use only. Although "spirited" street use would be the better term!

Thanks again everyone for your imput.

So Cal Mark · Post by **So Cal Mark** » Mon Sep 04, 2006 11:49 am

piston availability isn't very good these days, and finding the oem flat-top pistons is difficult. depending on what oversize you need. The last batch of pistons brought into the US was the high comp version., and those have pretty much been depleted. You may find that the vendors recommend what they have in stock

Joe Clemente · Post by **Joe Clemente** » Mon Sep 04, 2006 2:46 pm

Hey man, what's with the guru crap?

I believe the correct sarcastic dig used against me was "tuner king of the forum"... get it right man!

And I'm neither.

Seriously, I did not say no to 9.8s. I said it would they would be a better combination with your other material. Definitely makes more power. But the fact is that these pistons do require more octane in order to resist compressive detonation as lanciahf quite correctly pointed out. That doesn't mean you can't use them. I made the assumption you would be using a higher fuel grade already. Sorry bout that.

Fwiw, I've had 9.8s in both my 1800 and in my 2L without any problems. I've also always run my 2L on Chevron 94. Last time I tried 92 I got some ping happening. bad. Never tried my 2L on 93 as it isn't currently available locally. Years ago, we did have 93 premium leaded at the pumps which I used with my 1800. That was fine. Additionally, FWIW, I've always run 40/80s on both the intake and exhaust side without any real tractability issues. The stock exhaust cam thing is nonetheless sensible and you are fortunate to already have the cams to play with. My only issue with that setup is actually finding just one 40/80 to purchase if I had to. I personally wouldn't sell them separately.

I would also support what Mark said about piston availability. They're getting harder to find and you're options do tend to be restricted to whatever vendors carry. Alternatively, you could look into forged pistons but that equates to a lot more $$

Have a look and see what's available first. Ask and see what some others recommend and why and then you can make a more informed choice.

Best of luck with whatever you decide to do. I know you'll have a lot of fun with some more grunt from your 2L.

Cheers!

Joe

spiderrey · Post by **spiderrey** » Mon Sep 04, 2006 5:20 pm

i have a 2L with the 40 idfs like u. the bottom end was balanced following directions in crofts book. i installed an 1800 head to raise the compression ratio. the head was reworked by croft, his cams were also installed. i asked about the triple spring set up he had, he steered me away from it, i guess cause i told him the car would be for street use . he figured my motor had a 9.7 to compression ratio this way using stock flat top pistons. i can tell u this much, the car is a blast to drive. mark helped me get this project together and he seemed to be very happy with the results so far. i also installed larger chokes in the 40 idfs. and a much larger exhaust with headers. i had a stock 2l low mileage engine with headres and carbs before, the 2 setups r like night and day. i rarely get to drive the car right now, but when i do i feel like a little kid grinning a down the road. good luck

MIGHTY 8 · Post by **MIGHTY 8** » Mon Sep 04, 2006 9:46 pm

Hey spiderrey! Are your cooling issues so serious you must run sans hood?

Here I've been associated with this car since '92, and I'm still learning about its history! I guess the point is that the original spec 1800 head utilized the 9.7:1 compression pistons, while the 2L came with the lower compression pistons? Is this about right?

So the 9.8:1 that Vicks (for example) sells, they would equate to a much higher compression once installed in the car. Somewhere upwards of 10.1:1 and up.

Save for the questionable "High Octane Boost" that sells in auto shops, I would be leary of having to worry about detonation while uplifting fuel and not having any 94 octane around at the particular station.

I was really inclined to go with the the bigger boost, but now am thinking more towards the smaller 8.9s. Mainly for the fear of ruining a good solid engine such as in the above scenario.

Spiderrey, I hope to soon be able to join you in the ear to ear grin! Would love to see some pictures of your car. From the liitle image now, I can tell she's a beaut!

Thanks again to all

lanciahf · Post by **lanciahf** » Tue Sep 05, 2006 7:55 am

One moe tidbit about 9.8. As far as I know there are two versions of 9.8 pistons out there. One version made for the Euro 1756 motors (Lancia 1800 & Fiat 124 Coupe/Spider) and another for the 1585 motors that came with the Strada/Ritmo 105 TC. The 1585 9.8 have a larger dome than the 1756 9.8 pistons. The reason is the 1585 motor has a shorter stroke so Fiat used a larger dome to compensate. I think if these 9.8 are used in a 1.8 motor you will see more than 9.8 compression. When you contact a vendor ask them which 9.8 they are selling. I think the only pistons availabe are for the 1585 motors. Again see turbo124 for specifics.

spiderrey · Post by **spiderrey** » Tue Sep 05, 2006 5:50 pm

no, my car dosent run hot at all. that pic is from the day after it was finally completed, and on its wat to the french italian car show. hadnt had time to try and fit the hood yet., the hood actually didnt fit so i cut a hole in it and the air cleaners poked thru alittle. picked up an eclipser hood this weekend though. am hoping to graft the homp onto my hood and install larger aircleaners with trupets inside.

racydave · Post by **racydave** » Tue Sep 05, 2006 6:50 pm

The 1800 heads have a smaller cc, and would raise the compression some, and you could keep the same pistons. All head parts are interchangable. I think the vendors stock rebuilt heads. Would this be a good idea???? Dave

Hi-Comp Pistons: 124 Spider

Hi-Comp Pistons: 124 Spider

two versions of 9.8 (Maybe more)