It is currently Thu Mar 28, 2024 6:10 am

All times are UTC - 6 hours




Post new topic Reply to topic  [ 11 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: 1915cc hp at the Wheels
PostPosted: Sun May 15, 2016 9:57 pm 
Offline
User avatar

Joined: Fri Mar 16, 2012 8:02 pm
Posts: 58
Not so much a Tech problem as an interest in specs...
Today I was able to have my 1915cc powered '71 Beetle put on a Dyno to check the horse power "at the wheels".
My car's engine is relatively new (est. 500 miles on it since build). It is a big bore, full oil flow with 40/35.5 heads, 110 Engle cam, counter balanced crank, lightened flywheel. 009 distributor with electronic points. It has dual 40HPMX carbs and other street performance items...
Now for the interesting hp outcome. I went through the gears and let it run out to 5,000rpm. The result was 64 hp! I looked up some general specs and this works out to approx. 85hp at the flywheel. I'm not disappointed, but I have heard advertising and accounts of 90, 100, up to 120hp...not sure after what I put into my engine that I could do to get much more.
Anyway, this is just news and my 2 cents worth.
Thanks in advance for reading....

_________________
BeetleBill
Azle, TX

57 Oval Street Rod (Building)
71 Beetle (On The Road)
64 Karman Ghia - Long Gone, wish I had back!
66 Beetle - Long Gone


Top
 Profile  
 
 Post subject: Re: 1915cc hp at the Wheels
PostPosted: Mon May 16, 2016 12:16 am 
Offline
dLk Redneck
User avatar

Joined: Tue Jan 22, 2008 5:58 pm
Posts: 10199
Location: Spring
Sounds like you have something fishy going on. A stock 1600 puts out around 57Hp, just by adding a few bolt on changes such as dual carbs and exhaust will give you a 10-15% increase in power which would put you at or above the HP you are at now.

_________________
Ethan Dunlap
Spring, Texas


Last edited by ConcreteAce on Mon May 16, 2016 2:27 pm, edited 1 time in total.

Top
 Profile  
 
 Post subject: Re: 1915cc hp at the Wheels
PostPosted: Mon May 16, 2016 7:26 am 
Offline
User avatar

Joined: Fri Apr 19, 2013 3:31 pm
Posts: 1256
Location: Houston
I'm thinking that your max power might be at higher than 5000rpm. I know that my 1915 winds out over 6,000rpms. Just make sure that your rockers can handle that (bolt-on shaft and heavier springs).

_________________
Image
---------------It looks better in pictures!--------------


Top
 Profile  
 
 Post subject: Re: 1915cc hp at the Wheels
PostPosted: Mon May 16, 2016 9:35 am 
Offline
User avatar

Joined: Fri Mar 16, 2012 8:02 pm
Posts: 58
More Engine Info
Heads - Kühltek Motorwerks High Performance, Bore 94mm, Valves - 40mm x 35.5m, Single Springs
Crank - IAP Cast 69mm Counter Weighted, Balanced
Case - AS41 Dual Relief
Cam - Engle 110
Pistons - AA Hi Performance 94mm x 69mm
Carbs - EMPI Dual HPMX-40
Flywheel - Kühltek Motorwerks 200mm Lightened Flywheel
Distributor - 009 w/electronic points

Hope this helps with ideas. Yes, I only ran it up to 5,000 rpm. Mind you I'm not complaining, smooth running and is strong on the road. Just wondering about the hp reading...

_________________
BeetleBill
Azle, TX

57 Oval Street Rod (Building)
71 Beetle (On The Road)
64 Karman Ghia - Long Gone, wish I had back!
66 Beetle - Long Gone


Top
 Profile  
 
 Post subject: Re: 1915cc hp at the Wheels
PostPosted: Mon May 16, 2016 9:39 am 
Offline
Der Luft Doktor
User avatar

Joined: Tue Jan 22, 2008 3:31 pm
Posts: 7220
Location: OC CA
That does sound low. Here's a few things to think about:

1) VW transmissions can vary quite a lot in terms of their losses, yours could be more like 20+ percent, it's not uncommon.

2) Dyno's can vary a lot as well. The one you used could have been a bit on the conservative side. When was the last time it was calibrated? Is it well maintained? Likewise, a lot of those advertised numbers are from "happy dynos" that inflate the numbers. Big numbers sell, so keep that in mind when comparing to advertised numbers. For chassis dynos another thing is how hard they strap the car down. If they go too gorilla on it pulling it down into the rollers the driveline losses go way up. On that same note, were your tires properly inflated?

3) Were any corrections (SAE) applied, or are those the raw numbers? If they are raw numbers and it was say, really hot, or humid, your corrected numbers would be a bit higher to compensate.

4) Did they take wide-band O2 (air fuel ratio) measurements during the pulls? Carbs are usually jetted to run "pig rich" out of the box, because it's "safe" and will run "okay." If your AFR was really rich, say in the 10's, it will be a total dog. You could probably pick up 5-10+ hp easy by jetting it to about 12.5:1, assuming its way rich right now.

5) What is the compression ratio of your engine? Are you running running ratio rockers (run a 1.25:1 with the Engle W110)? What exhaust are you running (type and diameter)? What was your max ignition advance set at? Are your heads ported or un-ported?

6) I like Chesel's suggestion about the RPM's you pulled to. If you have HD or dual valve springs, and solid rocker shafts take it to 6k.

There are 1915's out there making ~130+ hp, but keep in mind those motors have tons and tons of money in them. The big ticket one is the heads. A really good set of heads is easily $1000, but that's really the key factor in how much power the motor will make. The heads determine the motor's potential. But then, everything has to be matched to the heads as well to realize that potential.

_________________
-Brian
IG: @mkzero55vw
'55 Outlaw Oval- 231 hp daily driver :shock:
'56 Oval Vert- Okrasa 36 hp
'52 Standard Split Window
1953 Fleetwood Travel Trailer
2010 FJ Cruiser- The Mountain Goat
30 Ford Model A Pickup Hotrod
Conklin Performance & Engineering


Top
 Profile  
 
 Post subject: Re: 1915cc hp at the Wheels
PostPosted: Mon May 16, 2016 4:26 pm 
Offline
User avatar

Joined: Fri Mar 16, 2012 8:02 pm
Posts: 58
Hmmmm let's see


1) VW transmissions can vary quite a lot in terms of their losses, yours could be more like 20+ percent, it's not uncommon.
My Transmission has stock gears (1971), but is I guess considered a Freeway Flyer based on hardened keys, Super Diff, Steel Forks, Welded 3rd & 4th Gear Hubs and Alum Side Covers.

2) Dyno's can vary a lot as well. The one you used could have been a bit on the conservative side. When was the last time it was calibrated? Is it well maintained? Likewise, a lot of those advertised numbers are from "happy dynos" that inflate the numbers. Big numbers sell, so keep that in mind when comparing to advertised numbers. For chassis dynos another thing is how hard they strap the car down. If they go too gorilla on it pulling it down into the rollers the driveline losses go way up. On that same note, were your tires properly inflated?
Have no idea about the Dyno. It is owned & operated by Azle High School Auto Tech. I had checked & inflated my tires that morning.

3) Were any corrections (SAE) applied, or are those the raw numbers? If they are raw numbers and it was say, really hot, or humid, your corrected numbers would be a bit higher to compensate.
No Information Available.

4) Did they take wide-band O2 (air fuel ratio) measurements during the pulls? Carbs are usually jetted to run "pig rich" out of the box, because it's "safe" and will run "okay." If your AFR was really rich, say in the 10's, it will be a total dog. You could probably pick up 5-10+ hp easy by jetting it to about 12.5:1, assuming its way rich right now.
O2 measurements were not taken. My carbs are not factory jetted. Based on poor performance from them in the factory settings & jetting, I rejetted and re-set them. Not sure about the AFR.

5) What is the compression ratio of your engine? Are you running running ratio rockers (run a 1.25:1 with the Engle W110)? What exhaust are you running (type and diameter)? What was your max ignition advance set at? Are your heads ported or un-ported?
Compression is right at 7.75:1. Rockers are stock VW. Exhaust is an EMPI Tuck-A-Way with 1.5" pipes. Heads are as purchased from IAP.

6) I like Chesel's suggestion about the RPM's you pulled to. If you have HD or dual valve springs, and solid rocker shafts take it to 6k.
As mentioned above the Heads have single Valve Springs. The Rocker Shafts are solid.

There are 1915's out there making ~130+ hp, but keep in mind those motors have tons and tons of money in them. The big ticket one is the heads. A really good set of heads is easily $1000, but that's really the key factor in how much power the motor will make. The heads determine the motor's potential. But then, everything has to be matched to the heads as well to realize that potential.

This is about as much info as I can find and note....Bill

_________________
BeetleBill
Azle, TX

57 Oval Street Rod (Building)
71 Beetle (On The Road)
64 Karman Ghia - Long Gone, wish I had back!
66 Beetle - Long Gone


Top
 Profile  
 
 Post subject: Re: 1915cc hp at the Wheels
PostPosted: Mon May 16, 2016 5:45 pm 
Offline
Der Luft Doktor
User avatar

Joined: Tue Jan 22, 2008 3:31 pm
Posts: 7220
Location: OC CA
A freeway flyer has nothing to do with the things you listed, they use a 3.88 R&P to give numerically lower gearing, that's what makes a tranny a freeway flyer. Those other things are good though!

You should ask them about the SAE correction factor, they should know what that is. What was the weather like that day?

If you are interested in getting more power out of it, take it somewhere with a wideband O2 sensor, its the only way to know for sure. Set it up at 12.5:1 on the main jet circuit. You are probably still richer than needed and therefore giving up power. You'd be surprised at how much power about .5 difference in AFR can make. You can set the idle circuit quite a bit leaner for better millage. I run mine right around stoichiometric on the idle circuit and get around 20 mph, but on the high end make 230+ hp around 12.5:1

Your CR is okay, a little on the low side, but not terrible. On your exhaust, are you running J-Pipes, or heater boxes. If heater boxes, ditch them in favor of J-pipes and you will immediately gain some power. Or you can get the large tube heater boxes if you "have to" have a heater. I didn't have a heater in mine when I lived in Houston, that's what jackets are for :lol: While you're at it, put on 1.25:1 rockers and get some more power.

Verify whether you have (single) HD springs, and if you do dyno it to 6k rpm next time, don't be skeerd :P

Your motor is a nice little combo and something is holding it back. I believe it should be capable of 100+ hp with some more tuning. Rockers, J-Tubes (if you don't already have them), and a proper AFR. Also set your max timing somewhere around 30-31 deg max and make sure you have a nice strong spark on all 4. Don't cheap out on the plug wires or buy fancy colored ones (like EMPI), use real Bosch parts in your ignition.

_________________
-Brian
IG: @mkzero55vw
'55 Outlaw Oval- 231 hp daily driver :shock:
'56 Oval Vert- Okrasa 36 hp
'52 Standard Split Window
1953 Fleetwood Travel Trailer
2010 FJ Cruiser- The Mountain Goat
30 Ford Model A Pickup Hotrod
Conklin Performance & Engineering


Top
 Profile  
 
 Post subject: Re: 1915cc hp at the Wheels
PostPosted: Mon May 16, 2016 6:16 pm 
Offline
User avatar

Joined: Fri Mar 16, 2012 8:02 pm
Posts: 58
A freeway flyer has nothing to do with the things you listed, they use a 3.88 R&P to give numerically lower gearing, that's what makes a tranny a freeway flyer. Those other things are good though!
Went with stock gearing to keep the fan speed optimum...

You should ask them about the SAE correction factor, they should know what that is. What was the weather like that day?
Am checking with the Auto Tech head teacher on the SAE Correction factor. Weather - this Sunday afternoon. Overcast about 78 degrees. Humidity was relatively high, but no rain.

If you are interested in getting more power out of it, take it somewhere with a wideband O2 sensor, its the only way to know for sure. Set it up at 12.5:1 on the main jet circuit. You are probably still richer than needed and therefore giving up power. You'd be surprised at how much power about .5 difference in AFR can make. You can set the idle circuit quite a bit leaner for better millage. I run mine right around stoichiometric on the idle circuit and get around 20 mph, but on the high end make 230+ hp around 12.5:1

Your CR is okay, a little on the low side, but not terrible. On your exhaust, are you running J-Pipes, or heater boxes. If heater boxes, ditch them in favor of J-pipes and you will immediately gain some power. Or you can get the large tube heater boxes if you "have to" have a heater. I didn't have a heater in mine when I lived in Houston, that's what jackets are for :lol: While you're at it, put on 1.25:1 rockers and get some more power.
Built CR specifically lower per Gene Berg's theory, running "J" Tubes. Will work on the 1.25:1 rockers.

Verify whether you have (single) HD springs, and if you do dyno it to 6k rpm next time, don't be skeerd
Checking with IAP to see about the Valve Springs...

Your motor is a nice little combo and something is holding it back. I believe it should be capable of 100+ hp with some more tuning. Rockers, J-Tubes (if you don't already have them), and a proper AFR. Also set your max timing somewhere around 30-31 deg max and make sure you have a nice strong spark on all 4. Don't cheap out on the plug wires or buy fancy colored ones (like EMPI), use real Bosch parts in your ignition.
I always run Bosch Plug Wires. I have reset the timing to 30 deg.

_________________
BeetleBill
Azle, TX

57 Oval Street Rod (Building)
71 Beetle (On The Road)
64 Karman Ghia - Long Gone, wish I had back!
66 Beetle - Long Gone


Top
 Profile  
 
 Post subject: Re: 1915cc hp at the Wheels
PostPosted: Mon May 16, 2016 8:34 pm 
Offline
Der Luft Doktor
User avatar

Joined: Tue Jan 22, 2008 3:31 pm
Posts: 7220
Location: OC CA
Berg's ideas are way outdated, and in many cases just plain wrong. I'm running a 2332 at 10.25:1 on the street on pump gas and my motor runs nice and cool. Berg would have said my engine would melt instantly, lol. Compression makes the engine efficient, which in turn means it has to work less to achieve the same output, which in turn means it runs cool. If you ever have your engine apart again, set the CR around 8.5:1 and enjoy the additional power. ;-)

_________________
-Brian
IG: @mkzero55vw
'55 Outlaw Oval- 231 hp daily driver :shock:
'56 Oval Vert- Okrasa 36 hp
'52 Standard Split Window
1953 Fleetwood Travel Trailer
2010 FJ Cruiser- The Mountain Goat
30 Ford Model A Pickup Hotrod
Conklin Performance & Engineering


Top
 Profile  
 
 Post subject: Re: 1915cc hp at the Wheels
PostPosted: Tue May 17, 2016 9:41 am 
Offline
User avatar

Joined: Fri Apr 19, 2013 3:31 pm
Posts: 1256
Location: Houston
mk-Zero wrote:
...While you're at it, put on 1.25:1 rockers and get some more power.


Question Brian, do you always have to have custom length pushrods with higher ratio rockers?

_________________
Image
---------------It looks better in pictures!--------------


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ]  Go to page 1, 2  Next

All times are UTC - 6 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group