TEMPO PISTONS?

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Anonymous

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I THINK I SAW SOME PLACE SOMEBODY HAD FORD TEMPO PISTONS IN A 200. WHAT MIGHT THE ADVANTAGE TO DOING THIS? MORE COMPRESSION? LONGER RODS? LIGHTER? OR WHAT?
 
I used them in mine to reach a compression ratio of 11.6:1 with my 66 head.

Since I swapped heads (1980 head) it dropped to only 10.1:1.... :cry: :cry: ;)

They are flat tops vs the stock dished piston and they weigh a few grams a piece less. They are a direct bolt in.

They are just another way of playing with the compression ratio. You can raise the compression by installing these pistons, milling the head or decking the block.

I did all 3 :eek: :eek:

Later,

Doug
 
THANKS GEEZ!
I CHECKED OUT YOUR SITE. WHAT EXACTLY IS AN HSC? IS THAT A 2.3 TURBO? WHAT ABOUT REGULAR 2.3 PISTONS? ARE THEY DIFFERENT?
 
No Problem ;)

You want the 2.3 litre HSC pistons. They were used in the Tempo/Topaz 4 cylinders (1980's). The other 2.3 litre pistons wont fit.

They are available in .010, 020, 030, 040, 060 over bore sizes. I'm running the .060 over on mine.


HSC stands for "high swirl combustion" if I remember correctly..

Later,

Doug
 
ALSO,YOU SAID YOU HAD YOUR HEAD MILLED .060". ARE THE TEMPO PISTONS A LITTLE SHORTER? IS THERE A BOLT IN ROD THAT IS ROUGHLY .060" LONGER? (BETTER ROD RATIO) INSTEAD OF MILLING?
 
8)

I am looking at either Tempo pistons(cheap flatops) or Chevy 305 forged pistons. Anyone ever used the 305's before" they are supposed to be a wee bit too tall so I was trying to work around that.
 
The replacement pistons are .010-.020 shorter in the 2.3 liter piston and the stock 200 piston.

I'm assuming that the reasoning is that usually decking the block is part of a good rebuild so if you take .010 off the deck to square it back up you will still have the stock .020 deck height.

Hopefully that makes sense when you read it...it's kinda early right now ;)

Never heard of anyone using the chevy piston. How much taller are they supposed to be??

Later,

Doug
 
Somebody posted the fact that KB (Keith Black?) had two types of forged 305 pistons avaliable off the shelf.

For the project engine I've been working on, I use Chevy pistons. Just don't tell any body, okay?. My standard size 305 forged pistons were originaly 1.53 inches tall. The blue print dimension can range from this to up to 1.563 inches. They have a wrist pin diameter of 0.927 inches, not 0.912 like in the Ford I6's. I'd say stock non-forged 305 pistons would fit most 200/250 I6's if you bore the wrist pin on the stock Ford rod, and then over bore 56 thou from the stock 3.68 bore. (I had the pistons milled down further to 1.475 inches, so I could fit them up to 3.3 Aussie rods and the 3.6 liter (221) Aussie crank on my 250 block).

I'm not certain if the pistons were originally 229 V6 items or 305V8. The only difference is the wrist pin bosses are centred differently to suit the flanged odd fire V6 crank. Apparently there were some 3.5 inch bore 200 Chevy V6's around, and a 170 I6 could fit these too. 305 pistons are easy to get, but most are 20 thou over, and forged 305 V8/229V6 pistons are very expensive as most people use Chevy 350V8 / 262 V6 engines. It's not likely a six with only 365 thou between the bores could swing a 76 thou overbore. I feel worried at 56 thou.

In Aussie and New Zealand, people who hop-up sixes tend to use four cylinder connecting rods and pistons as they are designed to cope with higher pistons speeds that the sixes have to contend with. Tempo HSC 2300 pistons and rods do 3300 feet per second with their 3.3 inch stroke at 6000 rpm. In a 250 I6, this would be 5000 rpm, and a mighty 6250 rpm with a little 200 I6. The HSC 2500 internals would do 3585 feet per second at 6000 rpm. Those pistons in a 250 I6 could handle 5500 rpm all day!
 
KB pistons list 3 different compression hts. 1.56, 1.43 and 1.26 Standard bore sizes are available. These are not forged but they are performance hypereutectic. At .056 over can your block handle that? I don't know. It could be sonic checked. Another possible piston is Chrysler 3.3 V6 with a bore of 3.66 and a .9009 pin, 1.26 comp. ht. It is a dished piston and is available in oversize.
 
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