Engine combo stats vs Expected Horsepower

RAW069 · 2013-03-13T03:04:33+00:00

G’day fellow Veedubbers I am new to this forum, but by no means new to the VW scene. The reason for my post is to gain opinion on engine combo vs expected horsepower. I recently had my brand new engine dyno’d which confirmed my suspicions that the engine was putting out less that expected. I will list my engine specs below if I can gain feedback on: - What horsepower I should expect - What I can do to find any missing ponies and/or improve HP - What loss through the trans I should be expecting The engine is in my 69 beetle which I am building for street/weekend use, but want some really decent power while also having good driveability. I am happy where the power is currently between 2500 and 6000, but just expected more. Engine is 2165cc - 78mm CW 4340 Crank - Lightened Flywheel - Standard length I Beam Rods - Engle W120 Cam - 1:1 ratio rockers on solid shafts - MOFOCO 050 Heads, 42mm Intake/37.5mm Exhaust, Port and Polish, supposedly 155 cfm @ 0.450 lift, Match ported manifolds ** - 9:1 CR - 44 Weber IDF’s, 36mm Venturi’s, Air correction: 200, Main jet: 140, Idle: 0.60 - 1 5/8 Inch tuned A1 Sidewinder exhaust The engine put out 106HP at the wheels @ 4700 and a pretty flat torque between 2500-4500 of approx 120NM at the wheels. I run 205 60 15’s on the rear and the trans has a heavy duty diff, 3.88 r+p with Welded 3rd & 4th gears. Usually HP loss is in the vicinity of 15% at the wheels, which means I am seeing 125HP at the flywheel. Dyno read out attached FYI ** I matched the manifolds myself, as they came standard. These were in the kit from Redline, I have wondered about the restrictive nature of the manifold further inside about half way up to the carbs. From what I can measure it is more like 32mm diameter inside here – is this something I should look at also? Any advice would be much appreciated. I think it would also be useful if a thread was started which detailed engine combo and HP output. Cheers in advance Cam

BiX Veteran Volks Folk

2,499 posts · joined Sep 2002 · 27 Mar 2013, 8:48 am

#949062

One thing I found with my engines is also the old idea of area below the curve, not just the peak power. My 1999cc, has 130rwhp, but is a more peaky. I had a old 1776 with (guess) 70rwhp but had a good spread from 1500 to 5000 rpm. The 1776 motor in was easier to drive and more forgiving, though maybe not quite as fast. I used to be able to mash the throttle and the limit was power not traction, plus it was more forgiving in slower corners, both of which are great on the street. The new motor is better and probably point to point faster, but needs allot more work to keep it on song and going. Its a race motor for when (soon!) i get back on the track. If your motor is for street use, the peak power number isn't always the best thing.

I have no sympathy for my car, only the wallet that pays for it!
Go hard or go home!!!!

Sides Veteran Volks Folk

2,220 posts · joined May 2007 · 27 Mar 2013, 9:29 am

#949064

BiX wrote:Its a race motor for when (soon!) i get back on the track.

6 years BiX... getting close to that magical 7 you liked to rib me about so much...

😂

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vassy66T1 Wow ... are U reading this?

2,120 posts · joined Jun 2003 · 27 Mar 2013, 8:01 pm

#949112

BiX wrote:One thing I found with my engines is also the old idea of area below the curve, not just the peak power. My 1999cc, has 130rwhp, but is a more peaky. I had a old 1776 with (guess) 70rwhp but had a good spread from 1500 to 5000 rpm. The 1776 motor in was easier to drive and more forgiving, though maybe not quite as fast. I used to be able to mash the throttle and the limit was power not traction, plus it was more forgiving in slower corners, both of which are great on the street. The new motor is better and probably point to point faster, but needs allot more work to keep it on song and going. Its a race motor for when (soon!) i get back on the track. If your motor is for street use, the peak power number isn't always the best thing.

Very good advice 👍

RAW069 Casual Dubber

32 posts · joined Feb 2013 · 2 Apr 2013, 7:45 am

#949707

Thanks again for all the good advice.

A couple of things that I will look at to start with then;

1. Open up manifolds, tapered down evenly from the carb to the head
2. Is it worth me looking at the venturi size? Or should I leave this at 36mm?
3. I was looking at replacing the rockers as the builder used second hand and the adjuster feet are a bit worn too. Is it worth looking at using 1.25 ratio rather than the 1.1, is there much to gain with the W120 cam?
4. Also I am wondering what the valve clearance should be with HD Aluminium Pushrods. The builder recommended standard 0.006", but I have read elsewhere the W120 is designed for 0.004"??

Cheers

1969 Beetle: Lowered, Narrowed, 2165
Fibreglass Buggy: Lifted, Shortened, 1640

RAW069 Casual Dubber

32 posts · joined Feb 2013 · 8 Apr 2013, 1:27 pm

#950587

RAW069 wrote:Thanks again for all the good advice.

A couple of things that I will look at to start with then;

1. Open up manifolds, tapered down evenly from the carb to the head
2. Is it worth me looking at the venturi size? Or should I leave this at 36mm?
3. I was looking at replacing the rockers as the builder used second hand and the adjuster feet are a bit worn too. Is it worth looking at using 1.25 ratio rather than the 1.1, is there much to gain with the W120 cam?
4. Also I am wondering what the valve clearance should be with HD Aluminium Pushrods. The builder recommended standard 0.006", but I have read elsewhere the W120 is designed for 0.004"??

Cheers

For those that might be interested, valve lash according to Engle for the W120 and HD Aluminum Pushrods is 0.004".

Does anyone have any input regarding using 1.25 ratio rockers??

Cheers

Cam

1969 Beetle: Lowered, Narrowed, 2165
Fibreglass Buggy: Lifted, Shortened, 1640