Short-stroke / big-bore, What's a 66mm x 96mm motor feel like? |
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Short-stroke / big-bore, What's a 66mm x 96mm motor feel like? |
Prospectfarms |
Mar 23 2012, 12:19 PM
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#1
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Member Group: Members Posts: 495 Joined: 7-March 11 From: Louisville, KY Member No.: 12,801 Region Association: Upper MidWest |
Saw a video of a 1911cc motor running and it sounded pretty good. It was carbureted and sounded "cammed." Makes me wonder what 96mm jugs do for a otherwise stock 1.7 engine.
Nothing wrong with 1.7 liters, but I really liked a 1835'ish cc type 1 put in a Beetle a few years ago. Torquey and very quick but reliable. What happens if I increase piston diameter on this short stroke engine? (I'll cross the MPS bridge when I get there.) 96mm by 66mm sounds weird, I'm trying to imagine how it would feel. Maybe even not worth doing? Don't think the valve seats were ever replaced on this engine so I'll have to send the heads out regardless. Ideally, I would increase stroke and displacement, but changing the cam, rods and crankshaft + everything else sounds like more than I'm willing to spend. |
TheCabinetmaker |
Mar 23 2012, 12:51 PM
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#2
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I drive my car everyday Group: Members Posts: 8,300 Joined: 8-May 03 From: Tulsa, Ok. Member No.: 666 |
Theres a lot of them out there. 1911 cc. Great upgrade to a 1.7. |
Prospectfarms |
Mar 23 2012, 01:56 PM
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#3
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Member Group: Members Posts: 495 Joined: 7-March 11 From: Louisville, KY Member No.: 12,801 Region Association: Upper MidWest |
Theres a lot of them out there. 1911 cc. Great upgrade to a 1.7. Thanks Curt, I speculate 66 x 96 feels like the 1.7 but your going faster. Compared to my experience with stroked motors of this displacement range where you get power earlier? I loved Ham's suggestion I read a while back of building a 78 x 90(stock cyl.) 1985cc, but that is more work and $ than I'm looking for. |
914werke |
Mar 23 2012, 02:45 PM
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#4
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"I got blisters on me fingers" Group: Members Posts: 10,082 Joined: 22-March 03 From: USofA Member No.: 453 Region Association: Pacific Northwest |
Very nice motor. less "lazy" than stock 2.0L but with equivalent pwr.
I mean lazy in that the stroke of the 2.0 provides torque w/o reving it, the 1.9 needs to be spun (IMG:style_emoticons/default/smile.gif) |
02loftsmoor |
Mar 23 2012, 03:15 PM
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#5
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Senior Member Group: Members Posts: 577 Joined: 26-June 11 From: Ft. Worth TX Member No.: 13,243 Region Association: Southwest Region |
That's what I've been checking on, big bore kit for my 1.7. keeping the stock FI and putting in a FI torquey cam. any thoughts?
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914_teener |
Mar 23 2012, 05:35 PM
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#6
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914 Guru Group: Members Posts: 5,198 Joined: 31-August 08 From: So. Cal Member No.: 9,489 Region Association: Southern California |
That's what I've been checking on, big bore kit for my 1.7. keeping the stock FI and putting in a FI torquey cam. any thoughts? That is my plan but: I am not convinced to keep the stock D-jet. I have run out of spare parts. Since the D-jet is hardmapped to the VE curve it will need to be adjusted. So my first plan is to install a wide band AFM to make sure I can adjust the MPS and get good at it if I keep the stock injection, or go with the M-squirt straight away. Watching a few thread on this board until I make the decision. |
pete-stevers |
Mar 23 2012, 08:19 PM
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#7
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saved from fire! Group: Members Posts: 2,641 Joined: 10-October 04 From: Abbotsford,BC, Canada Member No.: 2,914 Region Association: Pacific Northwest |
this is my build plan for the future as well...but will be running a cis rabbit sys on mine...but would love to hear what the "Jake Miester" has to say about a build up of this sort and his thoughts for what components should be matched for optimum longevity or performance
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Black22 |
Mar 23 2012, 08:53 PM
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#8
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Senior Member Group: Members Posts: 886 Joined: 1-November 07 From: Creswell, OR Member No.: 8,290 Region Association: Pacific Northwest |
I just built a 1911 from a 1.8L. Going to keep the L-jet too. Rebuild is complete and I have yet to install it and break it in. Super excited! It should be back in the car in about a month. I only get 1 day a week to work on it and am waiting on two more parts for other areas of the engine bay.
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Jake Raby |
Mar 23 2012, 09:16 PM
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#9
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
We've only built a few of these... The combo can be really fun, but its really easy to over cam them and I'd always keep a high speed port profile with this combo.
I have made 177HP with one of these combos as a race engine in the past.. |
Prospectfarms |
Mar 24 2012, 12:07 AM
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#10
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Member Group: Members Posts: 495 Joined: 7-March 11 From: Louisville, KY Member No.: 12,801 Region Association: Upper MidWest |
Useful information. Thanks very much. Now we have to come up with a catchy name for it. "Big bore" is oversell. "Ricer," nah, that's taken. Maybe, "The Combo?"
177 HP???? That must have been a high-revving beast. Neat. |
Prospectfarms |
Mar 24 2012, 12:12 AM
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#11
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Member Group: Members Posts: 495 Joined: 7-March 11 From: Louisville, KY Member No.: 12,801 Region Association: Upper MidWest |
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messix |
Mar 24 2012, 01:19 AM
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#12
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AKA "CLUTCH KILLER"! Group: Members Posts: 6,995 Joined: 14-April 05 From: between shit kickers and pinky lifters/ puget sound wa.north of Seattle south of Canada Member No.: 3,931 Region Association: Pacific Northwest |
I'd always keep a high speed port profile with this combo. AKA, smallish, or stock, (1.7) valves? valves are not the concern, it would be the port volume. the short stroke will have a slower piston speed compared to a longer stroke, this have an effect to where the intake pulse into the combustion chamber wont be as strong there by you would need a smaller port volume to encourage a higher velocity through the head. the valve can still be larger than stock to allow less restiction from the port to the combustion chamber. |
Bleyseng |
Mar 24 2012, 04:15 AM
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#13
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Aircooled Baby! Group: Members Posts: 13,034 Joined: 27-December 02 From: Seattle, Washington (for now) Member No.: 24 Region Association: Pacific Northwest |
That's what I've been checking on, big bore kit for my 1.7. keeping the stock FI and putting in a FI torquey cam. any thoughts? That is my plan but: I am not convinced to keep the stock D-jet. I have run out of spare parts. Since the D-jet is hardmapped to the VE curve it will need to be adjusted. So my first plan is to install a wide band AFM to make sure I can adjust the MPS and get good at it if I keep the stock injection, or go with the M-squirt straight away. Watching a few thread on this board until I make the decision. Pretty easy to do just install a Raby cam like a 9550. |
02loftsmoor |
Mar 24 2012, 09:30 AM
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#14
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Senior Member Group: Members Posts: 577 Joined: 26-June 11 From: Ft. Worth TX Member No.: 13,243 Region Association: Southwest Region |
What's your thoughts on a cam profile with stock FI. And a big bore kit
Wes We've only built a few of these... The combo can be really fun, but its really easy to over cam them and I'd always keep a high speed port profile with this combo. I have made 177HP with one of these combos as a race engine in the past.. |
Prospectfarms |
Mar 24 2012, 11:30 AM
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#15
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Member Group: Members Posts: 495 Joined: 7-March 11 From: Louisville, KY Member No.: 12,801 Region Association: Upper MidWest |
What's your thoughts on a cam profile with stock FI. And a big bore kit Wes We've only built a few of these... The combo can be really fun, but its really easy to over cam them and I'd always keep a high speed port profile with this combo. I have made 177HP with one of these combos as a race engine in the past.. Search (+1911 +cam) and you'll get all the info you want. #9550, or similar. "Massive Type!V" used to sell a "kit." and I believe still stocks the correct cam. Ask him directly. |
749142 |
Mar 24 2012, 02:15 PM
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#16
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Member Group: Members Posts: 254 Joined: 8-January 08 From: Bakersfield, Ca Member No.: 8,545 |
great engine... very reliable and fairly powerful. i prefer the 1911's over the 2056's.
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02loftsmoor |
Mar 24 2012, 03:35 PM
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#17
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Senior Member Group: Members Posts: 577 Joined: 26-June 11 From: Ft. Worth TX Member No.: 13,243 Region Association: Southwest Region |
why is that, smoother, easy revs ???
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Al Meredith |
Mar 24 2012, 07:35 PM
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#18
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Senior Member Group: Members Posts: 960 Joined: 4-November 04 From: Atlanta, ga Member No.: 3,061 |
I have both a 2056 and a 1911. The 2056 has much more torque. My 1911 has 1.8L heads and a raby cam (all the parts come from Jake). I think if you go to www.aircooledtechnology.com Jake has a dyno chart for both engines. You can compare for yourself.
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Black22 |
Mar 24 2012, 08:28 PM
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#19
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Senior Member Group: Members Posts: 886 Joined: 1-November 07 From: Creswell, OR Member No.: 8,290 Region Association: Pacific Northwest |
I've got a stock cam and 2.0L heads. I wonder if that's on the chart?
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914werke |
Mar 24 2012, 09:53 PM
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#20
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"I got blisters on me fingers" Group: Members Posts: 10,082 Joined: 22-March 03 From: USofA Member No.: 453 Region Association: Pacific Northwest |
That was the recipe I used.. stock cam, 2.0L heads, induction & exhaust
It Rocked! Of course I had a little help from Geoff dialing in the MPS using his LM1. |
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