Date: Mon, 25 Feb 2002 17:35:01 -0600
Reply-To: "Smola, Tony" <TSmola@TRIBUNE.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "Smola, Tony" <TSmola@TRIBUNE.COM>
Subject: Re: Ratio rockers was (dyno results from Boston Bobs) or true con
fessions of a gear head
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Robert,
I'm sorry to hear about the valve stems......I had a valve stem break off at
high rpms because I ground the valve retaining keepers a little bit to
prevent rotation of the valve........bad bad advice from a place here in So
Cal called AutoHaus or Pattech........I lost the valve in the cylinder while
coming back from Baja in my squareback at around 70 mph......needless to say
the valve was mangled and the head ruined.......I am not a fan of any sort
of ratio rocker that requires too much additional mods such as lashcaps,
swivel feet ( which need shimming behind the rocker shaft!).....then of
course you run into valve cover clearance....oh boy!.......I like it where
very little mods are necesary......and if ratio rockers are used if they are
just plug and play then that's fine....it you have to add all sorts of other
stuff, you're just adding variables to fail.
I think someone should look into increasing displacement.....increase bore
size and compression or just compression.
My 911SC has 170hp...the Euro version with higher compression and a g-grind
cam has 260? or something like that.
My ideas for a better wbx would be:
1) go to a g-grind Euro profile cam
2) increase compression to 10: 1...or whatever could handle 91 octane
3) since the AFM is based on airflow I would assume higher cmpression or
larger displacement would be accomodated for
by the flapper....this is why L-jetronic is better than D-jetronic on
914 Porsches....L meaning Luft or air
4) oversized pistons.....available?.....or from another motor.......
5) adjust fuel pressure for mods......
6) larger valves, not too large to affect the amount of material between
intake and exhaust valves......
7) extrusion honing of intake plenums and ports of heads.
8) sodiium valves? from the aircooled
these are just some ideas from the top of my head....some could work
others?....well
Hope everything works out....I'm looking forward to the comp information
Malibu Tony 85' Westy now at 5 degrees BTDC......( makes everyone less
confused on why 6 degrees BTDC)
78' 911SC Targa.......
-----Original Message-----
From: Robert Donalds [mailto:bostneng@fcl-us.net]
Sent: Saturday, February 23, 2002 6:16 AM
To: Smola, Tony
Cc: vanagon@GERRY.VANAGON.COM
Subject: Ratio rockers was (dyno results from Boston Bobs) or true
confessions of a gear head
Mr. Malibu wrote last week
Anyone know if the numbers are out from Boston Bobs and his tests on the
1.9L vs 2.1L
I'm looking for the info regarding the comparison between the 2 when both
motors are timed
at 5 degrees BTDC........ HP and torque curves comps.
Malibu Tony 85' Westy......6 degrees BTDC.....unknown new HP and
on 02/23/02
B Bob wrote
Toni
I have tested the difference in the timing with my 2.1 engine in the 85
camper using the
1.9 injection. see the post at the end of this email for my previous posting
to the list about this. I was set to dyno test a tiico engine and a 2.1
stock engine and a 1.9 engine and my big valve engine on a chassis dyno last
week end. I had borrowed a set of berg rockers and installed them on my big
valve engine prior to the testing due to the lengthily set up time. I
figured it is easier to go back to stock rockers from Berg rockers at the
test site. The Berg ratio rockers need lash caps to cover the ends of the
valves so the rocker has a larger area to sweep across the top of the valve.
The larger area and the wider sweep of the rocker across the lash caps
created a new problem.
Stainless steel is commonly used for custom and large valve replacement
valves and I have used thousands of this particular brand with no problems
and they are held in high regard among custom engine builders that I know.
I have even used them in sever duty applications for years and they have
withstood the abuses of the heartless brain dead rink rats that's drive the
air-cooled propane fueled Zambonis. These stainless valves have a hardened
end installed on the ends to prevent the adjusting screw from pounding the
stem. The problem is that when a lash cap is added to the end of these
valves the increased side load that is added is to much. I have spoken of
this in the past as the reason not to use the ratio rockers to prevent
intake valve guide wear. As it turns out this added side load is to much for
the hardened ends of the stainless steel valve and I had two valves brake
just below the lash caps with in 40 miles of installing ratio rockers. I
don't blame the valves for the failure they had 2000 miles on them and
showed not signs of other problems. I would not open myself up to those that
would say I just used cheap valves if I thought this was the case. So lets
not go there please
I have spoken with the valve manufacture and they said you cant use
lash caps with a stainless steel valve due the process used to make the
valve stem ends hard (thanks guys for sharing that a little to late) and I
also Called Clyde Berg He has assured me this problem will be added to the
installation instructions they provide with there ratio rockers. The bottom
line to this problem is don't use ratio rockers that need lash caps with
other than oem valves.
Needless to say the dyno testing was canceled. At this point I have
removed the heads from my race van to install a new set of the same valves
(no fear of this happening again as I will abstain from lash caps and ratio
rockers it is after all lent) I am also wondering why I did not notice the
narrowing of the intake manifolds at the head. I am now porting the
manifolds and matching the intake ports in the heads to the manifolds while
the heads are off. I will offer this process in the future with my big valve
engines.
stay tuned race fans for more race results as they happen
I will continue to test
remember its not a failure it s a learning curve
all right reserved
Boston Bob
PS I drove a van with tiico engine last week and I was not impressed
although it had great top end it lost drivability. by that I mean I had to
put the pedal to the metal to make the van get up and go. It might be that
that van had not been set up correctly but before you flame me come drive my
big valve race camper. The fellow that let me drive his tiico was heard to
repeatedly say WOW as he test drove my van
Chuck Mathis wrote
>About a year ago, I measured carefully and added a notch to my pulley for
>what should be 5 degrees BTDC on my '85 with about 50K miles at the time.
>Bearing in mind Boston Bob's early dyno let down with his big valve engine,
I
>will only say the engine seems to pull stronger from a stop and seems to
run
>stronger through the full RPM range
on /1/30/02 B Bob wrote
That was not a let down it was a learning curve and I shared it to show my
fellow learkers that even thought I thought the engine ran great the air
fuel ratio was way off. I was also trying to make the point that tuning can
no longer be done without checking fuel pressure and setting the injection
system up with the help of some kind of sampling of the exhaust gases!!!!!!!
In the first round of testing the big valve engine made more power cold and
made less power when warmed up due to the fact that as it warmed up it ran
leaner. This was compared to my 84 std valve 2.1 engine that I had used as a
standard base line for the 2.1 power comparison
I posted the note below after my second dyno session and Have not post more
about the final numbers because the numbers are in question due to the
method used for correcting weather factors on different days. I feel the
software that came with the Chassis dyno is flawed so that I can not use
data gathered on different days for comparison to each other I am however
confident that tests done on the same day are valid. This means that I have
to retest the big valve engine on the same day as the van I used for the
base line reading. I can tell you that I am very happy with the power the
big valve engine makes and I am going to redo the testing in the near
future. I have also found others that are willing to participate with tiico
conversions and stock vans to test on the same day so that comparisons to
stock 1.9, 2.1s,and big valve and in line 4s can be made
Bob
posted on 1/15/02
As you know I have been testing engines on the Chassis dyno. I finally got
my 84 2.1 big valve engine running correctly and tested it this past
Tuesday. I four pulls (tests) and made one change after the first two pulls
to see if more timing made more power and it did. let me recap I have
installed a 2.1 big valve engine in my 84 camper
I kept the digijet fuel injection system and left the stock dist and pulley.
when I changed the timing from the stock setting of 5 ATDC to about 4 or 5
BTDC I found two things first the dist tended to kick in more advance due to
the increase in RPM if I went past this point. by this I mean the timing
moved more than I was turning the dist. I did not check but I think the
centrifugal advance was engaging. the second thing I found was that the
engine made about 10 % more power throughout the power range Keep in mind
this is a 2.1 engine in a 84 with digijet.
I need to be clear that all the old time tuners say not to believe any flash
reading on a dyno with changes in timing!!!!!! I have found that changing
the timing makes the engine run hotter this can take time and might only
happen under constant loads (highway driving) hotter engines CAN loose power
and melted pistons can be a result
At this point I am still going threw the #s for all the tests and will
offer my finding when I am confident that I have the correction factors for
the different days of testing correct and the HP #s plotted on a spread
sheet with the torque included.
Bob Donalds
http://www.bostonengine.com <http://www.bostonengine.com>
As always
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