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bcrazy Samba Member
Joined: October 24, 2009 Posts: 239 Location: Oslo
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Posted: Sat Jul 12, 2025 9:46 am Post subject: 1679 SP build advice / or easy way to 75hp single port |
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In my 63 beetle i have this SP engine:
1584 (1500 heads with very light porting work, 3 angle valve job)
Scat C25 (1.1 intake rockers, exhaust 1:1)
7.9:1
1 3/8 4-1 header with "quiet pack" exhaust
2xSolex 35PDSIT
This engine runs ok, but compression should have been a bit higher, and especially the deck height ~0.060, should be closer
Got myself a small mill, and now plan to build the engine again.
My aim is 75 Hp and good low end torque
Got a good set of 88mm P&C, but can bore the case for for 90.5 if needed. (put i prefer to no split the case)
So my plan it is to cut the heads for more compression (8.5-9.0?), or if necessary also deck the case.
Is this a good recipe for ca 75 HP, and 130-135 nm? |
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67rustavenger Samba Member

Joined: February 24, 2015 Posts: 11015 Location: Oregon
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Posted: Sat Jul 12, 2025 10:26 am Post subject: Re: 1679 SP build advice / or easy way to 75hp single port |
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Machining on a short block is not a good idea. How would you keep machining chips out of the block?
Also, how would you go about securing the block to the table (<wrong term but, this is the best I can describe it) with the rods sticking out of the case? _________________ I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!
There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!
2003 Astrovan? GFYS again, Xevin!  |
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bcrazy Samba Member
Joined: October 24, 2009 Posts: 239 Location: Oslo
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Posted: Sat Jul 12, 2025 11:13 am Post subject: Re: 1679 SP build advice / or easy way to 75hp single port |
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If i need to correct deck height i will take the block apart.
If deck height measures to less than 1.5mm, i will just adjust the compression by machining the heads. |
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RWK Samba Member
Joined: June 24, 2009 Posts: 1610 Location: S.W. MI
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Posted: Sat Jul 12, 2025 12:04 pm Post subject: Re: 1679 SP build advice / or easy way to 75hp single port |
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Decking the case is always a good idea, a used case is usually sagged between the cylinders. _________________ 73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530 |
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Teeroy  Samba Member

Joined: April 20, 2003 Posts: 3840 Location: Eastern WA
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Posted: Sat Jul 12, 2025 5:24 pm Post subject: Re: 1679 SP build advice / or easy way to 75hp single port |
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If you dont want to split case to correct deck , take it off the bottom of the cylinders _________________ Pres. Rivercity VW Club www.rcvwclub.org
Founder Derr Wheat Panzers (DWP)
ARR #3
www.autosportsnorthwest.org |
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Alstrup Samba Member
Joined: July 12, 2007 Posts: 7822 Location: Videbaek Denmark
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Posted: Sun Jul 13, 2025 2:45 am Post subject: Re: 1679 SP build advice / or easy way to 75hp single port |
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bcrazy wrote: |
In my 63 beetle i have this SP engine:
1584 (1500 heads with very light porting work, 3 angle valve job)
Scat C25 (1.1 intake rockers, exhaust 1:1)
7.9:1
1 3/8 4-1 header with "quiet pack" exhaust
2xSolex 35PDSIT
This engine runs ok, but compression should have been a bit higher, and especially the deck height ~0.060, should be closer
Got myself a small mill, and now plan to build the engine again.
My aim is 75 Hp and good low end torque
Got a good set of 88mm P&C, but can bore the case for for 90.5 if needed. (put i prefer to no split the case)
So my plan it is to cut the heads for more compression (8.5-9.0?), or if necessary also deck the case.
Is this a good recipe for ca 75 HP, and 130-135 nm? |
Easy.
Replace the cam to something proper. CB2280 w. 1,25´s for good overall power. CB 2232 for very good mid rpm grunt. W100 for more rpm power.
Reduce deck to 0,040-0,045"
Set CR to 9-1 (8,8 with the 2232)
Figure out what intake length the engine wants. - Most likely about 20 mm more than what it is.
There is the potential for a true 75 hp sgl port. _________________ https://www.thesamba.com/vw/forum/viewtopic.php?t=435993 |
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Dusty1 Samba Member
Joined: April 16, 2004 Posts: 2091
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Posted: Sun Jul 13, 2025 2:33 pm Post subject: Re: 1679 SP build advice / or easy way to 75hp single port |
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Alstrup wrote: |
Easy.
Replace the cam to something proper. CB2280 w. 1,25´s for good overall power. CB 2232 for very good mid rpm grunt. W100 for more rpm power.
Reduce deck to 0,040-0,045"
Set CR to 9-1 (8,8 with the 2232)
Figure out what intake length the engine wants. - Most likely about 20 mm more than what it is.
There is the potential for a true 75 hp sgl port. |
There is just about everything I need for my so- called "Formula Street" motor.
I'm going to cheat and use dual port heads.
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