Author |
Message |
FRNKNSTNGHIA Samba Member
Joined: March 05, 2010 Posts: 411 Location: Kissimmee, FL
|
Posted: Tue Jul 30, 2019 8:25 pm Post subject: 1955cc Single Port |
|
|
1955cc
90.5x76
Ported Single Port heads
-SS Valves
-HD Single Springs
-Chromoly Retainers
-1.25 Rockers
-55cc
-10.0:1 Compression
-Micropolished Crank
-Dynamically Balanced rotating assembly
Dellorto FRDs
-29mm venturi
What kind of power/torque numbers?
|
|
Back to top |
|
|
67rustavenger Samba Member
Joined: February 24, 2015 Posts: 9663 Location: Oregon
|
Posted: Tue Jul 30, 2019 8:41 pm Post subject: Re: 1955cc Single Port |
|
|
More info needed.
Cam?
Exhaust?
Based on the lack info,
Sp heads, 1.25:1 rockers, stock cam, and exhaust, 10.0:1 CR.
65.5 HP@ 3500 RPM
Torque 126.5 @ 2500 RPM
Why bother building this?
It's limp! Unless you're looking to pull stumps.
Good Luck. _________________ 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! |
|
Back to top |
|
|
Pruneman99 Samba Member
Joined: February 22, 2012 Posts: 5013 Location: Oceanside
|
Posted: Tue Jul 30, 2019 10:28 pm Post subject: Re: 1955cc Single Port |
|
|
10-1 compression? Either you're running a cam with some serious overlap or race fuel.
If it's a big cam, it probably won't breathe enough unless you're force feeding it.
I can see the intake got worked, along with the exhaust. The exhaust looks hogged out though. If I was going down this path I'd left the exhaust pretty much alone except for around the bend and and guide.
Give some more details about induction, cam, exhaust, and purpose. It might help us see where you're going |
|
Back to top |
|
|
bugguy1967 Samba Member
Joined: January 16, 2008 Posts: 4338 Location: Los Angeles, CA 90016
|
Posted: Wed Jul 31, 2019 4:46 am Post subject: Re: 1955cc Single Port |
|
|
Geez! What did you do to the exhaust ports? You think your fluffing of the intakes warranted such a drastic increase of the exhaust port X-section?
Without removing the guides and porting, I'ma guess maybe a 5-10 HP bump at 800-1000 rpm lower than stock. _________________ "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" |
|
Back to top |
|
|
anthax Samba Member
Joined: October 21, 2016 Posts: 279 Location: Hälsingland, Sweden
|
Posted: Wed Jul 31, 2019 1:09 pm Post subject: Re: 1955cc Single Port |
|
|
Won't the single port strangle the increased engine displacement? |
|
Back to top |
|
|
Brian_e Samba Member
Joined: July 28, 2009 Posts: 3227 Location: Rapid City, SD
|
Posted: Wed Jul 31, 2019 1:50 pm Post subject: Re: 1955cc Single Port |
|
|
I like a nicely built single port.
Post some pics of the valve bowls. The bowls and the valve job are where most of the gain in a SP head happens.
The intake/exhaust flow ratio is pretty close to perfect with a blended intake bowl, a good valve job, and NOTHING done to the exhaust bowl or port. A very small amount of work in the exhaust bowl will make the flow numbers jump way up, and that is not what you want for a stump puller SP. Gotta keep things balanced.
You also need to be really careful with your cam selection in a SP.
Brian _________________ www.type-emotorsports.com |
|
Back to top |
|
|
Danwvw Samba Member
Joined: July 31, 2012 Posts: 8892 Location: Oregon Coast
|
Posted: Wed Jul 31, 2019 1:51 pm Post subject: Re: 1955cc Single Port |
|
|
Kind of an odd little motor but it would run ok not too high of rpm so power will be limited. The thing that I see wrong are the huge exhaust ports! Also the thing you will find that although the 29mm venturi's will open up the top end power the increased size venturi's may affect Idle and low end torque and general driveability. I don't think you will be able to jet that combo to have good over all air fuel ratio but that is just a hunch.
As for cam choice, probably the W-100 camshaft or the Eagle 2239 camshaft.
Probably just run 1.1 rockers unless you went with a Webcam 118 grind then the 1.25 ratio rockers would give about .460" valve lift and increase in total rpm without hurting low end torque.
Probably need to drop the compression down to 8.3 so it would run pump gas.
_________________ 1960 Beetle And 1679cc DP W-100 & Dual Zeniths! |
|
Back to top |
|
|
FRNKNSTNGHIA Samba Member
Joined: March 05, 2010 Posts: 411 Location: Kissimmee, FL
|
Posted: Thu Aug 01, 2019 12:16 pm Post subject: Re: 1955cc Single Port |
|
|
This is an unusual build I know.
W100 w/ 1.25 rockers currently
Will run 93 octane w/ additive. Hoping for a 96+ blend.
This motor is only intended for low rpm, 30-50mph, winding road action.
Doubt it will ever see an 1/8th or even a 1/4 mile drag strip. Probably won’t ever see over 80mph.
The builder did get a little carried away with the exhaust ports, probably because I told him I’d most likely be using a 38mm exhaust. Looking at the Dansk Sport Sebring Style Exhaust Setup.
The 29 venturis haven’t been added yet. Won’t get into that till closer to final longblock assembly. Will be searching for Dellorto experts to get their recommendations.
My goal is close to 100hp, and torque numbers stated above are what I estimated. Trust me if I wanted all out power I would have used dual port heads.
My 1970 Ghia came with a stock 1600 SP that I currently still have. I always said if it had an extra 30-40hp and extra 50tq, It would be perfect for my style of driving. |
|
Back to top |
|
|
Brian Samba Moderator
Joined: May 28, 2012 Posts: 8340 Location: Oceanside
|
Posted: Thu Aug 01, 2019 2:03 pm Post subject: Re: 1955cc Single Port |
|
|
You'll see a good improvement in power over stock. My 2007cc single port single carb was a stump puller forsure, shame I smashed it on a few too many rocks. You'll find that it'll be a little tricky with tuning, but once you get it in there it can be smooth as stock. _________________ Wash your hands
'69 Bug
'68 Baja Truck
'71 Bug
'68 Camper
Only losers litter |
|
Back to top |
|
|
FRNKNSTNGHIA Samba Member
Joined: March 05, 2010 Posts: 411 Location: Kissimmee, FL
|
Posted: Thu Aug 01, 2019 5:28 pm Post subject: Re: 1955cc Single Port |
|
|
Brian wrote: |
You'll see a good improvement in power over stock. My 2007cc single port single carb was a stump puller forsure, shame I smashed it on a few too many rocks. You'll find that it'll be a little tricky with tuning, but once you get it in there it can be smooth as stock. |
I expect a slightly high idle, probably around 950. Hoping with some good recommendations on pre-jetting the carbs, use of a wide-band and dyno, we can tune the motor to very street-able manner. |
|
Back to top |
|
|
Brian Samba Moderator
Joined: May 28, 2012 Posts: 8340 Location: Oceanside
|
Posted: Thu Aug 01, 2019 7:30 pm Post subject: Re: 1955cc Single Port |
|
|
950 is on the "low" side. I'd aim at 1000 flat and jet/tune accordingly, definitely utilize a wideband and post up here.
Your compression should make for an interesting mix, what's the max octane you can get over there? I was just out in Winterhaven, and filled up the rental car in Williamsburg, but paid no mind.
But yea, definitely watch the wideband and listen for pinging. _________________ Wash your hands
'69 Bug
'68 Baja Truck
'71 Bug
'68 Camper
Only losers litter |
|
Back to top |
|
|
Alstrup Samba Member
Joined: July 12, 2007 Posts: 7177 Location: Videbaek Denmark
|
Posted: Fri Aug 02, 2019 2:53 am Post subject: Re: 1955cc Single Port |
|
|
Sgl. port idle quality is influenced on several things apart from cam duration/overlap. Intake port length and exhaust options are equally "interesting" One thing is for certain. That giant exhaust port is not good for anything but the bragging rights, ESPECIALLY not when you are after lower rpm punch. Also it will affect the idle quality quite a bit. The easy way to improve it a little will be to make the classical split lift 1,25/1,1 rockers which will help a good deal. The next thing would be to install 37,5 or 39 mm intake valves. But that´s most likely out of the question here.
The FRD´s definitely need 29 mm venturies. But the manifolds are too short. They need an extension between carb and manifold to improve plenum volume. 20 - 25 mm is good. This will aid in both idle stability improvement and mid to upper rpm power.
When you are after lower to mid rpm power you should really look into getting a shorty header type of muffler like this: http://vwparts.aircooled.net/Vintage-Speed-Equal-Length-38mm-155-203-035SF-p/155-203-035sf.htm
Or this http://www.ttexhausts.com/vw-beetle-exhaust/
Ignition. The typical 009 will work if recurved some. But with todays options it may be time to look for other solutions, because an engine like that will need a somewhat funky ignition curve to work well.
Power. Sgl port engines rev relatively high with a little more cam duration. Also with the large exh ports I expect the engine to peak up around 5000 to 5200ish rpm. I let the computer chew on the combo with some head data from a 1955 sgl port engine that I built some years back with exactly the above recommended VS muffler. It shows 107 hp @ 5250 and peak torque of 130 lbs @ 3500. How close yours are is impossible to say. |
|
Back to top |
|
|
FRNKNSTNGHIA Samba Member
Joined: March 05, 2010 Posts: 411 Location: Kissimmee, FL
|
Posted: Fri Aug 02, 2019 7:42 am Post subject: Re: 1955cc Single Port |
|
|
Thanks for the advice as always Alstrup.
I'll speak to builder to see if they can swap out the rockers to 1.1, this is for the exhaust side or intake side?
I will see about having some manifold extensions built. Shouldn't be too hard to fabricate something that small.
I know you recommended the style of exhausts, what are your thoughts on something like this? 38mm as well. Full Stainless.
https://www2.cip1.com/ProductDetails.asp?ProductCode=C23%2D251%2D92760
As for the question about OCTANE. We do have 93 pump, but at certain locations you can purchase 100 octane. Or you can buy 5 gallon jugs of race fuel pretty easy. So I feel with the 6 gallons of 93 and 6 gallons of 100/race fuel, should give me plenty of octane to not cause detonation.
As for the FRDs with 29 venturi, any thoughts on jet sizes all around? Something to get me to a good starting point. |
|
Back to top |
|
|
Alstrup Samba Member
Joined: July 12, 2007 Posts: 7177 Location: Videbaek Denmark
|
Posted: Fri Aug 02, 2019 10:35 am Post subject: Re: 1955cc Single Port |
|
|
FRNKNSTNGHIA wrote: |
I know you recommended the style of exhausts, what are your thoughts on something like this? 38mm as well. Full Stainless.
https://www2.cip1.com/ProductDetails.asp?ProductCode=C23%2D251%2D92760
Frankly, I have never had one in my hands nor on the dyno. Personally I always thought they were a little daft since its not a 4-2-1 and its not a proper 4 into 1. - On a speedster where you want the Carrera GT look, fair enough.
As for the question about OCTANE. We do have 93 pump, but at certain locations you can purchase 100 octane. Or you can buy 5 gallon jugs of race fuel pretty easy. So I feel with the 6 gallons of 93 and 6 gallons of 100/race fuel, should give me plenty of octane to not cause detonation.
As for the FRDs with 29 venturi, any thoughts on jet sizes all around? Something to get me to a good starting point.
Again, I have very little experience with these carbs. With a 29 mm venturies I would imagine something like 145 main 180 air as a starting point.
|
|
|
Back to top |
|
|
Machecoul Samba Member
Joined: November 12, 2015 Posts: 50 Location: Europe
|
Posted: Fri Aug 02, 2019 12:55 pm Post subject: Re: 1955cc Single Port |
|
|
FRNKNSTNGHIA wrote: |
I'll speak to builder to see if they can swap out the rockers to 1.1, this is for the exhaust side or intake side?
|
Exhaust side. |
|
Back to top |
|
|
FRNKNSTNGHIA Samba Member
Joined: March 05, 2010 Posts: 411 Location: Kissimmee, FL
|
Posted: Fri Aug 02, 2019 4:41 pm Post subject: Re: 1955cc Single Port |
|
|
As for ignition you recommended a 009. Do you not recommend a SVDA distributor for the dual carb setup? |
|
Back to top |
|
|
Alstrup Samba Member
Joined: July 12, 2007 Posts: 7177 Location: Videbaek Denmark
|
Posted: Fri Aug 02, 2019 4:51 pm Post subject: Re: 1955cc Single Port |
|
|
SVDA can be made to work. But as I wrote above, today there are good affordable programmable systems that are better. |
|
Back to top |
|
|
TheViking Samba Member
Joined: March 04, 2016 Posts: 278 Location: Norway
|
Posted: Sat Aug 03, 2019 6:16 am Post subject: Re: 1955cc Single Port |
|
|
67rustavenger wrote: |
More info needed.
Cam?
Exhaust?
Based on the lack info,
Sp heads, 1.25:1 rockers, stock cam, and exhaust, 10.0:1 CR.
65.5 HP@ 3500 RPM
Torque 126.5 @ 2500 RPM
Why bother building this?
It's limp! Unless you're looking to pull stumps.
Good Luck. |
More than that. My 1584cc single port with kadrons got 61 whp... |
|
Back to top |
|
|
FRNKNSTNGHIA Samba Member
Joined: March 05, 2010 Posts: 411 Location: Kissimmee, FL
|
|
Back to top |
|
|
67rustavenger Samba Member
Joined: February 24, 2015 Posts: 9663 Location: Oregon
|
Posted: Sat Aug 03, 2019 11:19 pm Post subject: Re: 1955cc Single Port |
|
|
Not really. The engine (as planned) is choked by the design/plan.
It cannot breath.
It'll have a lot of torque. But no real usable horsepower.
TheViking wrote: |
67rustavenger wrote: |
More info needed.
Cam?
Exhaust?
Based on the lack info,
Sp heads, 1.25:1 rockers, stock cam, and exhaust, 10.0:1 CR.
65.5 HP@ 3500 RPM
Torque 126.5 @ 2500 RPM
Why bother building this?
It's limp! Unless you're looking to pull stumps.
Good Luck. |
More than that. My 1584cc single port with kadrons got 61 whp... |
_________________ 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! |
|
Back to top |
|
|
|