Good usable 90mm pistons & cylinders wanted
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Good usable 90mm pistons & cylinders wanted
I'm looking for a set of six good usable circa 90mm pistons and cylinders to drop into the 2.2E engine I have, in anticipation of the original Biral cylinders being corroded when I get into them. I understand widening the stud holes for the 2.2 studs can be hit and miss so I'm reluctant to buy new when they may potentially be weakened by the machining.
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
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Re: Good usable 90mm pistons & cylinders wanted
.
Do you realise that if fitting 90mm pistons you'll end up with quite a low compression ratio ?
.
Do you realise that if fitting 90mm pistons you'll end up with quite a low compression ratio ?
.
Andy
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
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Re: Good usable 90mm pistons & cylinders wanted
No, I was expecting it to be higher. This is on a 66mm crank. Am I being daft (as usual)?Lightweight_911 wrote: ↑Thu Apr 18, 2024 1:01 pm .
Do you realise that if fitting 90mm pistons you'll end up with quite a low compression ratio ?
.
Not sure where I can I see the rod length and pin height for the 2.2E vs a 2.7. I presume it depends which 90mm pistons I use too?
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
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- Nurse, I think I need some assistance
- Posts: 16875
- Joined: Wed Nov 12, 2003 10:48 pm
- Location: Worcs/W Mids border
Re: Good usable 90mm pistons & cylinders wanted
.
The 2.7 litre 911 engines have a stroke of 70.4mm so if using the 90mm pistons with a 66mm stroke, the swept volume - & hence the compression ratio - will be (significantly) lower.
For instance, if using std 2.7RS pistons with a 66mm crank you'll end up with (from memory) a CR of ~ 7:1
Thus to get any benefit from using 90mm pistons in a 2.2 litre engine you'd need higher compression versions (eg JE pistons) ...
.
The 2.7 litre 911 engines have a stroke of 70.4mm so if using the 90mm pistons with a 66mm stroke, the swept volume - & hence the compression ratio - will be (significantly) lower.
For instance, if using std 2.7RS pistons with a 66mm crank you'll end up with (from memory) a CR of ~ 7:1
Thus to get any benefit from using 90mm pistons in a 2.2 litre engine you'd need higher compression versions (eg JE pistons) ...
.
Andy
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
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- DDK 1st, 2nd and 3rd for me!
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Re: Good usable 90mm pistons & cylinders wanted
Ah cool, thanks. So used barrels/cylinders are of use to me but I'd need modern pistons.Lightweight_911 wrote:.
The 2.7 litre 911 engines have a stroke of 70.4mm so if using the 90mm pistons with a 66mm stroke, the swept volume - & hence the compression ratio - will be (significantly) lower.
For instance, if using std 2.7RS pistons with a 66mm crank you'll end up with (from memory) a CR of ~ 7:1
Thus to get any benefit from using 90mm pistons in a 2.2 litre engine you'd need higher compression versions (eg JE pistons) ...
.
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1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
Re: Good usable 90mm pistons & cylinders wanted
Why not stick with barrels that don’t need the cases and heads machining ? A high compression 2.2/2.3 with let flywheel etc is a wonderful engine
James
1973 911 2.4S
1993 964 C2
2010 987 Spyder
1973 MGB Roadster
Its not how fast you go, but how you go fast
1973 911 2.4S
1993 964 C2
2010 987 Spyder
1973 MGB Roadster
Its not how fast you go, but how you go fast
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Re: Good usable 90mm pistons & cylinders wanted
Agree, that ^^^ is a much easier engine and risk-free Rob.
I thought a '2.4' conversion to a 2.2 engine was a bit meccarno? Could be wrong, been a very long time since I thought about 2.4's as opposed to 3.2's.
I think the Dempsey book goes through a lot of the common tune-up configurations?
I thought a '2.4' conversion to a 2.2 engine was a bit meccarno? Could be wrong, been a very long time since I thought about 2.4's as opposed to 3.2's.
I think the Dempsey book goes through a lot of the common tune-up configurations?
73T 911 Coupe, road/hillclimber 3.2L
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
Lola t 492 / 3.2 hillclimb racer
Boxster 987 Gen II 2.9
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Re: Good usable 90mm pistons & cylinders wanted
The bigger crank is plug and play I think, but a bigger bore engine is more what I'm looking for.911hillclimber wrote: ↑Fri Apr 19, 2024 9:32 am Agree, that ^^^ is a much easier engine and risk-free Rob.
I thought a '2.4' conversion to a 2.2 engine was a bit meccarno? Could be wrong, been a very long time since I thought about 2.4's as opposed to 3.2's.
I think the Dempsey book goes through a lot of the common tune-up configurations?
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
-
- DDK 1st, 2nd and 3rd for me!
- Posts: 2061
- Joined: Thu Jul 08, 2021 8:18 am
- Location: Lichfield
Re: Good usable 90mm pistons & cylinders wanted
ok I did some calcs and notionally the 2.7 pistons must be 1.908mm shorter than the 2.2 pistons. That assumes the cylinder heads are the same (anybody know the truth of that?) If the heads are indeed the same then the "average unswept length" of the cylinder will all go with the pistons. If the heads are different then all bets are off in terms of making a theoretical calculation.Lightweight_911 wrote: ↑Thu Apr 18, 2024 1:01 pm
Do you realise that if fitting 90mm pistons you'll end up with quite a low compression ratio ?
Retaining that assumption that the heads are the same, the "unswept length" of the 2.2E engine would increase from 8.15mm to 10.06mm, decreasing the compression ratio from 9.1:1 to 7.5625:1, a little lower than the 2.7, as you said. Of course, practice trumps theory.
Based on that calculation, taking 2.75mm out of the deck height would convert that into a 10:1 compression 2.5 engine. Can the 911 engine take that kind of modification? I'm not really seriously considering it, just curious really. I'd expect to run into problems with the pistons coinciding with the valves, since they're not designed to fit that tightly.
Last edited by RobFrost on Mon Apr 22, 2024 10:07 am, edited 1 time in total.
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
-
- Nurse, I think I need some assistance
- Posts: 16875
- Joined: Wed Nov 12, 2003 10:48 pm
- Location: Worcs/W Mids border
Re: Good usable 90mm pistons & cylinders wanted
.
I thought you were originally asking for a set of 90mm pistons & barrels for a 2.2L not a 2.4 ?
.
I thought you were originally asking for a set of 90mm pistons & barrels for a 2.2L not a 2.4 ?
.
Andy
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
“Adding power makes you faster on the straights;
- subtracting weight makes you faster everywhere”
-
- DDK 1st, 2nd and 3rd for me!
- Posts: 2061
- Joined: Thu Jul 08, 2021 8:18 am
- Location: Lichfield
Re: Good usable 90mm pistons & cylinders wanted
Yes, sorry my bad now edited. (Same pistons tho I think;)Lightweight_911 wrote: ↑Mon Apr 22, 2024 9:08 am
I thought you were originally asking for a set of 90mm pistons & barrels for a 2.2L not a 2.4 ?
Here are the calcs
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
-
- DDK 1st, 2nd and 3rd for me!
- Posts: 2061
- Joined: Thu Jul 08, 2021 8:18 am
- Location: Lichfield
Re: Good usable 90mm pistons & cylinders wanted
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
-
- DDK 1st, 2nd and 3rd for me!
- Posts: 2061
- Joined: Thu Jul 08, 2021 8:18 am
- Location: Lichfield
Re: Good usable 90mm pistons & cylinders wanted
1970 911T, Signal orange (Restoration thread)
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.
1988 3.2 Carrera backdate, Black
2001 996 Turbo, Lapis blue (am I allowed to put that here?)
I'm looking for a pre-impact bumper 911S or other high-revving 911 to restore - please let me know if you see one.