Piston swap. Worth it?

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TimDart

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I'm pulling my motor 3 years after a rebuild to check it over and sort a few things.
When I built the motor I used Sealed Power cast pistons which give a comp ratio of around 8.6. I'm considering removing these pistons for the same make version that offers around 9.5+ compression.
Intention is to remove the ridge in the bore and slot the new pistons in.

The overall intention is to up compression amd allow for a 268 cam.
currently the Dart runs low 14's and is super reliable, i'd like the same but running mid 13's
2300 stall
3.23-3.91 rear 9undecided as yet)

What do you guys think?
 
Sounds like a good plan to me. New pistons is the best way to up the compresion. Is it worth it? Well thats realy kind of up to you. What I would do is price up what it will cost then I would see if I thought the cost verses the performance gain was worth it. Good luckHave fun and happy motoring.
 
I'm going for the lazy option. I'm assuming the bore is all good and therefore it will just need a ridge ream to allow the new pistons and rings to bed in .
Won't know for sure until I take the heads off next weekend.
i'll check the bottom end. but dont want to pay for decking/honing as the motor is still very new and provides excellent oil presure. But as its out of the car, its worth looking at some cheap/ish performance upgrades.
If i'm wrong minded on this, feel free to tell me!
 
If you were using moly coated rings there likely won't be any ridge.

I pulled the head on a 2.2 4cyl to replace the head gasket at 176,000 miles and there was no ridge and there was still signs of the original honing marks. The moly coated rings sure cut down cylinder bore wear! :)
 
If its a good running motor and u have no issues, when u pull heads and everything looks good, why change pistons when u could just mill heads .040-.060 to bump comp up, just an idea, less work.
 
Don't bother. You're disturbing the balance, and you need to at least scuff the bores for the new rings. they will not seat on a run in surface. one point of compression IMO is not worth the effort or the risk.
 
Thanks for the responses, sort of whatI was looking for. I guess i'm conscious that I built the motor a litle conservatively in the first place. While its all apart i'll do some proper measurements and try to establish the true compression rate before changing the cam a size up (to 268).
 
I believe that's a way better idea. make use of what you got. I'm sure you can get more from it.
 
If the motor has say 300hp now then jumping to 9.5 is a about a 9hp gain.
Up the cam in conjunction you could gain around 25hp +/-
Meeting your et goals? you'll have to find out yourself, sounds like you might be a hair shy but thats JMO.
 
Yup, thanks for the input. i'll leave the motor but will update cam and rear gears to suit andi'll post next season when I hit 13's:king:
 
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