Back to the original question:
You can indeed put onto your 71mm crank big-bore pistons that were originally designed for a 66mm crank motor. You'll need 1/2" spacers. That will move the heads 1/2" out from the case, which will start leading you into issues with the cooling tin, issues with fitting the engine in the engine bay, issues with pushrod tube length and pushrod length... And probably others that don't spring to mind right away.
Solution: Buy big-bore pistons that were designed for a motor with a 71mm crank, or get ready to build lots of custom parts.
--DD
type 4 2056
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BergRace
- Posts: 606
- Joined: Wed Oct 04, 2000 12:01 am
type 4 2056
The 1300S is NOT a 1300, it's a DP1600 in the 1200/1300 body with swing axle and stock disc's up front.
I use the same tranny myself.
J.
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-56 T1 hopefully soon with a F.I. T4 (AN engine)
I use the same tranny myself.
J.
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-56 T1 hopefully soon with a F.I. T4 (AN engine)
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ringmorph
type 4 2056
Dave, why would he need half inch spacers? He would only need a shim of about 10 thousandths by my calculations. Are the 2.0 rods a different length than the 1800 rods?
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Tom Notch
- Moderator
- Posts: 3332
- Joined: Mon Apr 10, 2000 12:01 am
type 4 2056
The 2L rods are 4mm longer (131mm vs 127mm) plus half the stroke increase length, rounded up to 5mm = roughly .2" per side. Add to this maybe a bit more to drop compression or the heads can be opened up, just make sure you have adequate deck.
See this page for a few technical specs of T4 engines.
http://home.att.net/~airdoc/t4ramblings.html
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Tom Notch
See this page for a few technical specs of T4 engines.
http://home.att.net/~airdoc/t4ramblings.html
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Tom Notch
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Joseph
- Posts: 593
- Joined: Sat Jul 01, 2000 12:01 am
type 4 2056
Check the piston crown to pin center. Its
another factor in determining how much to
space up the cylinder for getting the deck
size you want.
Joe (of the West)
another factor in determining how much to
space up the cylinder for getting the deck
size you want.
Joe (of the West)
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Tom Notch
- Moderator
- Posts: 3332
- Joined: Mon Apr 10, 2000 12:01 am
type 4 2056
Having re-read the original post, here is my take at most of the questions
Originally posted by 66 1300:
I'm going to build a type 4 for my beetle. What I have now is a stock 1971 cc, the heads, 1800, will need an overhaul, and the P&C will be changed.
Good start
How are the quality of 96 mm pistons made for the 66 mm crank. These are not forged. I know they can be used on the 2.0L with spacers under them, but should I?
You are buying piston and cyl. sets, might as well get forged ones for a 2L. Then everything will be a good fit.
With this P&C, 9.5:1 compression, 3 angle valve job and 1800 heads with 41 x 34, stock heater boxes cut off and welded to an extractor, 40 or 45 mm Weber/Dellorto carbs.
The engine will have a porsche 911 cooling.
I want the engine to have good torque at low/midrange and peek hp just before 6.000 rpm.
Good kind of power curve and I would go with the 45s. 40s could be the limiting factor especially if you went bigger in the future.
What cam should I use?
Go to Web or Fat just for examples. Don't get too radical on the cam, I suggest staying under 260 degrees at.050 lift with maybe more duration on the exhaust
Do I need dual valve springs?
YES!
How much Hp will this give me, when built right?
Depends on a few factors which you still list as variables but 140 is at the high end of what you could get
How much torque will this give?
LOTS!!
How about the gas mileage.
Driver dependent (right foot size) and will be effected by cam overlap
And finally, when bolted to a 1300S transmission in a 66 1300, with stock size tires, how fast will it go?
It wii break any and all speed limits excecpt on the autobahn.
Hope someone can answer this!
Hope I did
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Tom Notch
Originally posted by 66 1300:
I'm going to build a type 4 for my beetle. What I have now is a stock 1971 cc, the heads, 1800, will need an overhaul, and the P&C will be changed.
Good start
How are the quality of 96 mm pistons made for the 66 mm crank. These are not forged. I know they can be used on the 2.0L with spacers under them, but should I?
You are buying piston and cyl. sets, might as well get forged ones for a 2L. Then everything will be a good fit.
With this P&C, 9.5:1 compression, 3 angle valve job and 1800 heads with 41 x 34, stock heater boxes cut off and welded to an extractor, 40 or 45 mm Weber/Dellorto carbs.
The engine will have a porsche 911 cooling.
I want the engine to have good torque at low/midrange and peek hp just before 6.000 rpm.
Good kind of power curve and I would go with the 45s. 40s could be the limiting factor especially if you went bigger in the future.
What cam should I use?
Go to Web or Fat just for examples. Don't get too radical on the cam, I suggest staying under 260 degrees at.050 lift with maybe more duration on the exhaust
Do I need dual valve springs?
YES!
How much Hp will this give me, when built right?
Depends on a few factors which you still list as variables but 140 is at the high end of what you could get
How much torque will this give?
LOTS!!
How about the gas mileage.
Driver dependent (right foot size) and will be effected by cam overlap
And finally, when bolted to a 1300S transmission in a 66 1300, with stock size tires, how fast will it go?
It wii break any and all speed limits excecpt on the autobahn.
Hope someone can answer this!
Hope I did
------------------
Tom Notch
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steve stromberg
- Posts: 142
- Joined: Fri Oct 13, 2000 12:01 am
type 4 2056
You can use Type 1 pistons in Type 4 barrels. If you use " piston these are made for a 82mm stroke I used these when I build my "Double Nickel" 1955cc type 1 with waterboxer crank 90.5 by 76 vs. 88.5 by69 stock. The shorter piston pin height allows you to increase crank stroke without needing spacers as engine is not wider than stock.This can be used on Type 4 ie.1700 T-4 Barrels 90mm opened up for 90.5 used with 71mm 2.0 crank.STEVE 818 508 0582
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Dave_Darling
- Posts: 2534
- Joined: Thu Apr 27, 2000 12:01 am
type 4 2056
Tom notch responds to the question:
> Do I need dual valve springs?
>
> YES!
I disagree. I don't think dual springs are needed until somewhat over 6000 RPM. I also am very hesitant to go with them. A 914 engine builder that I highly respect (he used to build street engines as well as E-Prod class motors--160-180 HP out of a 1.8 spinning at 7000 RPM) once told me "Dual springs on a Type IV engine are EVIL!!" He was referring to the amount of material that needs to be cut out of the head to fit a specific type of dual spring kit. I don't know if there are better options these days, but I don't think they're worth it on a reasonably-sane street motor anyway.
--DD
> Do I need dual valve springs?
>
> YES!
I disagree. I don't think dual springs are needed until somewhat over 6000 RPM. I also am very hesitant to go with them. A 914 engine builder that I highly respect (he used to build street engines as well as E-Prod class motors--160-180 HP out of a 1.8 spinning at 7000 RPM) once told me "Dual springs on a Type IV engine are EVIL!!" He was referring to the amount of material that needs to be cut out of the head to fit a specific type of dual spring kit. I don't know if there are better options these days, but I don't think they're worth it on a reasonably-sane street motor anyway.
--DD