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dbo@samba
Samba Member
Joined: March 31, 2009
Posts: 15
Location: Central Coast of California
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 Posted: Mon Aug 24, 2015 1:00 pm Post subject: 1679cc Mighty Mouse Spinoff |
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Last edited by dbo@samba on Thu Aug 27, 2015 10:40 am; edited 7 times in total |
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Matthew
Samba Member
Joined: January 29, 2004
Posts: 1760
Location: Eastern Tennessee
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| Posted: Mon Aug 24, 2015 2:42 pm Post subject: |
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Subscribed. Back in the 70's lots of people built hot 1700s (1679). Now they will all be 1915 or 2275. I say build it.
You will want 32 vents in those 40 idfs for your combo or bigger carbs like 44 IDFs.
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1965 Beetle sedan
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theastronaut
Samba Member
Joined: November 19, 2007
Posts: 1631
Location: Anderson, SC
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| Posted: Mon Aug 24, 2015 3:00 pm Post subject: |
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Signing up for this one. Sounds like a good combo. Might want to step down to a 1.5" if you're not planning on making it bigger in the future?
37mm venturis were reccomended for my 1679 build with ported 40x35's, 86B, 1.4's, and a 1.5 sidewinder. I'm hoping to make power around 7000-7500 rpm. I think 130-140 hp is possible if you can make it breathe well enough up top. The FK series will broaden the powerband, I kinda wish I had gone with one instead of the 86b but I didn't want to sleeve the block.
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Strive for perfection in everything. Take the best that exist and make it better. If it doesn't exist, create it. Accept nothing nearly right or good enough."
-Sir Henry Royce, co-founder of Rolls-Royce
'64 Beetle Sunroof OG Bahama Blue
'63 Beetle Vert
'66 Beetle
'88 Festiva L
'89 Festiva L
'64 Chevy C10
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mark tucker
Samba Member
Joined: April 08, 2009
Posts: 23937
Location: SHALIMAR ,FLORIDA
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| Posted: Mon Aug 24, 2015 3:07 pm Post subject: |
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hey it's mr astro nut!!! how's that balance job going??????holly sheep shit batman did I just hyjack a thread????
87 hp &82 tq  |
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theastronaut
Samba Member
Joined: November 19, 2007
Posts: 1631
Location: Anderson, SC
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| Posted: Mon Aug 24, 2015 3:22 pm Post subject: |
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| mark tucker wrote: |
hey it's mr astro nut!!! how's that balance job going??????holly sheep shit batman did I just hyjack a thread????
87 hp &82 tq |
It's still balanced as far as I know. Been doing a good job of keeping the other parts company. 
_________________
Strive for perfection in everything. Take the best that exist and make it better. If it doesn't exist, create it. Accept nothing nearly right or good enough."
-Sir Henry Royce, co-founder of Rolls-Royce
'64 Beetle Sunroof OG Bahama Blue
'63 Beetle Vert
'66 Beetle
'88 Festiva L
'89 Festiva L
'64 Chevy C10
'66 Chevy C10 |
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Matthew
Samba Member
Joined: January 29, 2004
Posts: 1760
Location: Eastern Tennessee
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| Posted: Mon Aug 24, 2015 3:22 pm Post subject: |
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FWIW Dub Dyno says your combo peaks at 113hp and 100 ft lbs. if you step up to 44 idfs it goes to 128hp and 101 ft lbs. With 44 Idfs and 1 1/2 exhaust it makes 127hp at 7000 and 104 ft lbs at 6000 rpm.
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1965 Beetle sedan
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Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7212
Location: Videbaek Denmark
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| Posted: Mon Aug 24, 2015 4:20 pm Post subject: |
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| 115-120ish sounds about right. Port volume is too large for the displacement, so it will never get really good airspeed. Around 150 nm torque : |
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VWCOOL
Samba Member
Joined: June 02, 2006
Posts: 1821
Location: Down under
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| Posted: Mon Aug 24, 2015 5:37 pm Post subject: |
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| Build it properly with slip-ins for a true 'no machine' DIY motor and prove all the 'thin wall' conspiracy theorists wrong again |
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Matthew
Samba Member
Joined: January 29, 2004
Posts: 1760
Location: Eastern Tennessee
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| Posted: Mon Aug 24, 2015 6:14 pm Post subject: |
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DBO, do you already have those L5 heads? If not maybe have a head porter make a set custom tailored to the engine for improved port velocity.
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bugguy1967
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Joined: January 16, 2008
Posts: 4341
Location: Los Angeles, CA 90016
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| Posted: Mon Aug 24, 2015 9:59 pm Post subject: |
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The 88 slip-ins are now the thickest cylinders available. Only the case register is super thin, which really isn't important. The head side has the same register as a common 90.5/92.
Yes, use a smaller ported set of 40x35s. Brother's VW does a round and oval port 40x35. Thye keep them stocked, usually at all times.
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"A petrol engine can start readily, run smoothly and give every appearance of being in good order, without necessarily being in good tune." - Colin Campbell, "The Sportscar Engine" |
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MURZI
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Joined: August 25, 2005
Posts: 5063
Location: Madisonville, La
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| Posted: Tue Aug 25, 2015 6:38 am Post subject: |
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88 AA's are heavy. I am not sure I would spin them to 7500 plus. Look at a custom Pistons.
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62 vert
2276
Tims welded heads
45 Dells
A1 sidewinder
Fk44 cam |
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Brian_e
Samba Member
Joined: July 28, 2009
Posts: 3284
Location: Rapid City, SD
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| Posted: Tue Aug 25, 2015 6:57 am Post subject: |
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| MURZI wrote: |
| 88 AA's are heavy. I am not sure I would spin them to 7500 plus. Look at a custom Pistons. |
I agree. Some custom JE's with a minimal skirt, a thinner dome, and move the pin height up. Then you can shorten the pushrods a bunch as well. You are gonna need to use the lightest rotating and valve train parts you can to keep it alive at high RPM.
It will quickly start to turn into a custom machining experiment, but it should be fun and cost a bunch!! All the haters will tell you to just build a mild 1915, and they are right, but I say keep going. It will be a good learning experience, and it will be a hoot to drive if you get all your math correct.
I would assume you have seen JPM's 1600 mouse engine?
Brian. |
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Alstrup
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Joined: July 12, 2007
Posts: 7212
Location: Videbaek Denmark
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| Posted: Tue Aug 25, 2015 7:38 am Post subject: |
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If 7500 is the goal/ max rev, find a set of NOS Mahle pistons. They will handle that. With the regular AAīs I would stop at 7 grand too.
On a second note, if you want to rev that high you might want to increase carburettor size, or that in itself will be a limiting factor.
T |
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dbo@samba
Samba Member
Joined: March 31, 2009
Posts: 15
Location: Central Coast of California
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| Posted: Tue Aug 25, 2015 8:44 pm Post subject: |
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| theastronaut wrote: |
Signing up for this one. Sounds like a good combo. Might want to step down to a 1.5" if you're not planning on making it bigger in the future?
37mm venturis were reccomended for my 1679 build with ported 40x35's, 86B, 1.4's, and a 1.5 sidewinder. I'm hoping to make power around 7000-7500 rpm. I think 130-140 hp is possible if you can make it breathe well enough up top. The FK series will broaden the powerband, I kinda wish I had gone with one instead of the 86b but I didn't want to sleeve the block. |
Yes, I hear a lot of people saying you'll need more flow through the heads with the amount of lift. It will be dyno'd to put all of our theories to rest. =) |
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dbo@samba
Samba Member
Joined: March 31, 2009
Posts: 15
Location: Central Coast of California
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| Posted: Tue Aug 25, 2015 8:58 pm Post subject: |
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| Alstrup wrote: |
If 7500 is the goal/ max rev, find a set of NOS Mahle pistons. They will handle that. With the regular AAīs I would stop at 7 grand too.
On a second note, if you want to rev that high you might want to increase carburettor size, or that in itself will be a limiting factor.
T |
Yes I was planning to rev limit @ 7K. I want a higher rev engine, but keep it within the limitations of the parts chosen. |
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dbo@samba
Samba Member
Joined: March 31, 2009
Posts: 15
Location: Central Coast of California
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| Posted: Tue Aug 25, 2015 9:05 pm Post subject: |
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| theastronaut wrote: |
Signing up for this one. Sounds like a good combo. Might want to step down to a 1.5" if you're not planning on making it bigger in the future?
37mm venturis were reccomended for my 1679 build with ported 40x35's, 86B, 1.4's, and a 1.5 sidewinder. I'm hoping to make power around 7000-7500 rpm. I think 130-140 hp is possible if you can make it breathe well enough up top. The FK series will broaden the powerband, I kinda wish I had gone with one instead of the 86b but I didn't want to sleeve the block. |
Yes your build was the source of inspiration and slight iteration. =) |
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mchn13
Samba Member
Joined: February 28, 2008
Posts: 240
Location: Columbia, SC
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| Posted: Tue Aug 25, 2015 9:16 pm Post subject: |
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| dbo@samba wrote: |
| theastronaut wrote: |
Signing up for this one. Sounds like a good combo. Might want to step down to a 1.5" if you're not planning on making it bigger in the future?
37mm venturis were reccomended for my 1679 build with ported 40x35's, 86B, 1.4's, and a 1.5 sidewinder. I'm hoping to make power around 7000-7500 rpm. I think 130-140 hp is possible if you can make it breathe well enough up top. The FK series will broaden the powerband, I kinda wish I had gone with one instead of the 86b but I didn't want to sleeve the block. |
Yes your build was the source of inspiration and slight iteration. =) |
I was about to say your build and astronauts are fairly similar. My 1679 has a little less cam and smaller heads. It's cool other people are building small hot engines tho.
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Steve Moore
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always over budget on something.always |
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dbo@samba
Samba Member
Joined: March 31, 2009
Posts: 15
Location: Central Coast of California
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| Posted: Tue Aug 25, 2015 9:50 pm Post subject: |
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| Matthew wrote: |
| DBO, do you already have those L5 heads? If not maybe have a head porter make a set custom tailored to the engine for improved port velocity. |
I haven't purchase heads yet. I have the pistons coming by the end of the week so I can take a deck height measurement first. |
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Alstrup
Samba Member
Joined: July 12, 2007
Posts: 7212
Location: Videbaek Denmark
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| Posted: Tue Aug 25, 2015 10:47 pm Post subject: |
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You might want to give the Tims family a shout, or maybe Brotherīs and tell them what you have and want, then they can taylor a set of heads for you. There could easily be a 10 hp difference over shelf heads.
If you do want shelf heads, CBīs cnc round port is more in the direction of what you need for the parts you have chosen. I have seen a couple of track 1600īs that pulled 150 hp with these heads and very minor work to them. - more CR and cam duration though.
T |
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dbo@samba
Samba Member
Joined: March 31, 2009
Posts: 15
Location: Central Coast of California
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| Posted: Wed Aug 26, 2015 7:08 am Post subject: |
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| Alstrup wrote: |
You might want to give the Tims family a shout, or maybe Brotherīs and tell them what you have and want, then they can taylor a set of heads for you. There could easily be a 10 hp difference over shelf heads.
If you do want shelf heads, CBīs cnc round port is more in the direction of what you need for the parts you have chosen. I have seen a couple of track 1600īs that pulled 150 hp with these heads and very minor work to them. - more CR and cam duration though.
T |
Thanks. Having the most overall hp was not the intent, but rather a some what budget build that can be upgraded later since my short block is still good. The FK44 and larger heads were chosen to give me more top end, but also allow for a larger displacement later without tossing my heads and starting over. |
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