'73SResto: 2.2E Pistons swap

[yopurp]

So, we are putting the engine back together and turns out the original pistons are a bit too pitted to go back in. The project didn't budget for new pistons. So, we have located a set of 2.2L 'E' pistons that fit the budget. I know that this will raise the compression up to a ratio that is close to having to worry about detonation. As previously posted, I've already machined the heads to fit twin plugs, but haven't the $$ to put the twin ignition in yet (maybe next year).

I read in Bruce Andersen's book, that putting 2.2L S pistons into a 2.4L S engine only raises the compression from 8.5:1 up to 9.66, which he says is still w/in safe single-plug limits. Does anyone know what the E pistons do to the compression? Remember, this is NOT a race car. I did modify the cams slightly (nothing radical). Also, I live in CA where we can only get 91 Octane gas.

Will this set up be safe (as far as detonation goes), and will the result be streetable and livable? Also, what are the options on pistons that are pitted? Can they be machined or is there too much clearance as a result?

Thanks

[yopurp]

Oh yeah, just to pre-empt Shawn,

No I didn't plan this! Well, actually back at the beginning I did consider this as a performance upgrade, but backed off due to the cost. Damn this thing is one slippery slope. Shawn - stop. Don't say it. I already know.....

[Shawn]

I wasn't gonna say nothin...



Seriously, I hate to hear that your project is going over budget. It's no laughing matter when the wallet gets hit. That could push your completion date back as well. Shawn

[yopurp]

Shawn - hope you are enjoying this. Just remember, payback is looming as your turn comes this coming winter, does it not?

Some more details: turns out on the original piston heads, two of them are worn and a bit pitted. Wayne's got extra 2.4S ones he can use to replace the two. However, I have the option of spending an extra $300 for a 'slightly used set of 2.2 E pistons (Mahle-fact OEM #'s). Since the E's are a bit lower (does anyone know the specifics?) compression than the S's, I'm thinking its probably safe (ie: less than 10:1) for running on 91 gas w/single plugs. The E's are much cleaner than my orig ones (looks like much less mileage). I'd just like a sanity check from the gurus on the board.

I was thinking about doing something like this originally, but a new piston set was 1,000-1,200 bucks. This seems like a good oppty but want to double check I'm not missing something.

[JCR]

Chris,

Soon you will be laughing at all of US because your car will be DONE. With only oil changes and the occasional waxing to do. and of course lots of driving!!

I'll still be rehabilitating the molestation issues of my car - all the while envying YOU! I'm currently stockpiling the parts I need, and will hit it hard this winter while she's in hibernation.

Spend the extra few bucks and do it right - you'll be glad you did in the long run. I just don't know what to tell you specifically what "right" is - but I'm sure it'll cost more!!

[yopurp]

Thanks Jared.

BTW - what the speaker layout in your car? I've seen the '70-71 dash with the speaker panel in the top of the dash. I saw a '72 w/just the perforated small holes, speaker under the dash. Mine has no speaker panel at all, but 6inch rounds in the door panels below the window handles. Is that orig, or not?

Also, heard that compression in the 2.4's in europe were higher compression than US spec? Did they just keep the 2.2 cycl heads for Europe since they didn't have to pass smog? Just curious if this is true or not.

[69Sman]

hey Chris, just for record, you can find 100 Octane Unleaded at MANY Union 76 stations througout SoCal...I use it ONLY in my hi-compression 356 engine...

[beginner]

Originally posted by yopurp
heard that compression in the 2.4's in europe were higher compression than US spec? Did they just keep the 2.2 cycl heads for Europe since they didn't have to pass smog?

No-- all 2.4s had same compression.

I copied and pasted a couple of posts from another similar thread, here it is:

Rob,

Read your earlier post, you made a mistake, any 2.2 piston when used in combination with a 70.4mm stroke and compared to a 66mm stroke will increase the compression of the piston. I cc'd 2.2E pistons with 9.1 compression on a short stroke, with a long stroke I picked up the compression to 9.5 to one on the dot. The 2.2S setup will bring it to over 10 to 1 on a long stroke. As for valve to piston clearance all motors are dimensionally to same from center of case to top of cylinder. Thus the deck height of 2.2S and a 2.4S will be the same at top dead center overlap, the shorter the stroke the longer the rods and the longer the stroke the shorter the rods must get to keep the overall engine dimension to same giver a common wrist pin height. The valve to piston clearance of the 2.2S piston is the same regardless of the stroke of the engine, just the swept volume changes to increase compression.

Jeff
--------------------------

Your right Jeff..... It something like 10.2/1........ For S pistons....

Robert......
--------------------------


Oh dear.... another error in Wayne's book... and Bruce's for that matter...

[beginner]

yopurp

--You definitely need twin plugging for 10.2/1....

or perhaps E pistons for 9.5/1...

[JCR]

Chris,

Mine came with an Alpine CD and MB Quarts in the doors - a hot setup at one time. Also had an Alpine alarm complete with power locks and fancy remote.

None of it lasted a week - ripped it all out immediately (boy did that feel good). What a rats nest of wires! I would rather have no radio at all - which I will for a while.

My dash is from a later car with high vents, so there is no speaker grille. I can see the cut brown ground wire under the dash where the speaker was - so I know it had one.

My understanding is that all 72/73s had the separate speaker grille dash unless radio delete; then the top was solid. I think the one piece perf'ed dashes are from earlier cars.

I have not heard of a stereo door mount speaker option for 73, but what's funny is the doors have the cutouts to acommodate speakers? Were they just thinking ahead - or accommodating aftermarket stereo installs? So many cars have eventually had speakers mounted here - usually violating the map pocket which hides them.