Somender Singh grooves

[usedgeo]

Originally Posted by ZugyNA

Could you post a pic of that grooving job? Did you try leaving the head gasket off to increase the compression? I'm assuming an old B&S engine.

It was an old B&S. I used the head gasket. I didn't take a picture. It comes off easy I might take one later. I used three grooves very much like the one picutured on the Somender Singh site. Here are some picks from the site.
http://somender-singh.com/content/view/68/49/

[VetteOwner]

uhh the one plug right next to the whieish looking one in the pic of 4, it looks like it got majorly bent...

it could have turned white because it wasnt gapped correctly or it wore to big of a gap.

[ZugyNA]

Originally Posted by Ryland

I'm temped to do this to my moped, as it has poor low end power, and a pretty stable top speed, so any gain should be noticed, right?

I once removed the head gasket from a 2-cycle moped and it seemed to increase the power. I used some non-hardening gasket goop instead...though they don't recommend using any on head gaskets.

Might try this AND grooving it?

[ZugyNA]

Originally Posted by usedgeo

It was an old B&S. I used the head gasket. I didn't take a picture. It comes off easy I might take one later. I used three grooves very much like the one picutured on the Somender Singh site. Here are some picks from the site.

I have the head that has one groove. Might give it a go...1, 2, or 3 grooves....no head gasket.

[usedgeo]

Originally Posted by usedgeo

Sorry Bill. I just made three grooves like the one on Somender's site. I put the head back on without any pictures. I will try to document the Saturn better.

Finally took some time for pictures of the B&S head. These grooves may be too large. When the grooves were smaller the exhaust valve was bare metal except for the shadow on the side toward the piston. Now it has a thin white carbon film on it. What seems unique to me is that the oil residue in the head is leaving a glossy hard film as it burns. This is an old B&S so it burns a little oil. I only smell the oil burning for a few seconds at start up and then it cleans up. That is the nicest result of this mod .

I made the grooves larger because the smaller ones had started to plug a bit and I just wanted to see what would happen. I think this is taking on the characteristics of an open combustion chamber with the grooves so large.

I guess I should point out that before the mod the spark plug was an oily oil fouled plug and it was never cleaned. It just cleaned up during operation.

I hope you enjoy the pictures. The links are to slightly different views.

http://xs.to/xs.php?h=xs217&d=07272&f=B_SHEAD1.JPG

http://xs.to/xs.php?h=xs217&d=07272&f=B_SHEAD2.JPG

http://xs.to/xs.php?h=xs217&d=07272&f=PISTON1.JPG

http://xs.to/xs.php?h=xs217&d=07272&f=PISTON2.JPG

[DRW]

Thanks for the pics. Is there any evidence of turbulence on the piston top? I don't see any in the pics. I wonder if cleaning the piston top might let any turbulent patterns show up better?

[ZugyNA]

I did some grooves yesterday on a B&S push type mower. The head on this engine is around .275" thick and the grooves were .065" to .070" deep max. Used a hacksaw blade to get the depth and a 3 cornered file to finish them.

The center groove is aimed at the plug...the 2 side grooves at the edges of the valves...intake on left...exhaust on right. Used the old head gasket.

note: I'm just guessing as to where they should be and how deep.

Might have to highlight the URL & hit ENTER to see these....


http://www.nonags.org/members/nijqk/bsgroovesbefore.jpg

This engine doesn't really use that much oil...the "carbon" you see is PIB (?) that I got from dissolving some butyl caulk in gasoline...letting it settle and using the oily result in the mower. Had way too much in it, but was using it anyway. The "carbon" is mostly sticky and gooey PIB...at least that's what it's supposed to be.

Using straight gas now.


http://www.nonags.org/members/nijqk/BSGROOVESafter.JPG

The roll of screen is supposed to be a cross between a Kendon screen scroll and Lynze. This is inserted in the tube coming from the carb and going over to the intake valve. Just a single layer of galvanized steel screen. Supposed to help vaporize the gas. If you take the air cleaner off of one of these engines and pull the rope with the plug wire off...you'll see a lot of gas coming back out of the carb...the screen is supposed to catch some of this and allow it to vaporize better...at least that is the theory.

The result? It runs. Seems to have plenty of power.

[usedgeo]

Well the deed os done. It was a lot of work for 30 minutes of grooving. I am not a fast mechanic. I have heard that one can remove the head on a DOHC Saturn wihout pulling the timing chaning cover. There was no way it was going to happen on the SOHC engine. Darn there are a lot of bolts on the accessories and the body and right side (front) of the engine are closer than I would prefer. Here are a couple pics.
















As soon as I got the head off I was a bit dissappointed. The squish area was not as large as I had expected based on other pictures I had seen on the internet. Also the piston is slightly dished. The flat face on the piston is only about a 3/8 inch ring on the outside. Also one of the valve reliefs intersects the groove in the head. It had what appeared to me a lot going against it. Also the combusion chambers alaready have an appearance similar to the Brings and stratton post grooves. I decided it would be foolish to do all this work and not put in grooves so I put in grooves. I intended to use a 1/8 inch ball bit and go 1/16 inch deep. When I got set up all I had was a 3/16 inch ball bit so I only went .040 inches deep. The router attachment on the dremmel worked pretty good. I bobbled on one groove.

I was sorely tempted to decarbon the valves and other things but all I did was do the grooves. Nothing more. Oh for the sake of completeness I should say I dropped a spark plug and had to replace it with same make, same number, same gap.

I should not discuss this yet but I would be curious if I were you. This is based on a scangauge that is calibrated a bit conservative but was calibrated at slower speeds doing pulse and glide. I reserve the right to correct this data as time passes. The fuel gauge is matching the scangauge quite well at this point.

I just got it together last evening. I drove 150 miles last night and this morning just for the heck of it. At 60 mpg that's cheaper entertainment than some movies . Naturally we all want to know if it made a difference. The Saturn already ran pretty good. So far by the scan gauge I more than exceeded my expectations. It has a slight bit more torque so that when I tried P&G on my usual route I over accelerated a bit or achieved my desired speeds a bit sooner than expected. This is a subtle impression and not readily quantifiable.

Okay, I ran 3 loops on the freeway at average speeds of 60 mph. That was three runs west and three runs east. The temps ran 80 -95 deg F. There was a 5-10 mph breeze against me on part of one east run. It switched to a light cross wind. There is a construction zone at 55 mph but I made up for it. Otherwise I drove constant speed trying to avoid drafts from the moderate traffic. I did not include the acceleration and coast which would constitute a P&G cycled even though the legs are 14 miles long. It is pretty easy to roll up 1-2 mpg coasting off the freeway. The water temp ran 196-235 deg F. The IAT ran 180-200 deg F.

Actually on one west bound stretch I had to stop and pull some grill block as I had removed the fuse for the cooling fan and it got up over 235 deg. F. I did include that stop and start. That stop and start hurt my average a bit as I was on a freeway and traffic cramped my style. I pulled too much block and cooled off too much. Yeah, I could use some shutters. Incidently while 220 is very good at 238 WT the car seemed to start losing mileage. I did not go long at those temps.

east 56 mpg
west 72 mpg
east 57 mpg
west 69 mpg
east 57 mpg
west 70 mpg

This averages to 63.5 mpg. The very best I have done on this loop before was 58 mpg. I did not consider that singular event valid enough to claim that mileage. I had confidently claimed 56 mpg on this loop before the grooves. I'll split the difference for 57 mpg pre groove. Using 57 mpg as the base this is an 11.4% improvement.

I then did a 70-75 mph shorter run that will lack accuracy. Actaully the scangauge had me at a max of 79 mph. I was just going faster than 70 to get an idea of 70 mph mileage. These were just 4 mile runs.

west 60 mpg
east 50 mpg
average 55 mpg.

Today the total was 96.7 miles, 60.2 mpg 48 mph ave.
Yesterday 53.8 miles, 60.2 mpg, 40 mph ave.
I knocked a bit off my tank average. Sorry leftover bananas. It's the price one has to pay for knowledge sometimes.

I consider my 60 mpg at 60 mph goal accomplished unless I come up against another scangage fluke. I will certainly keep you posted.

I still have the the LC1 wideband O2 sensor in the box. Gee when does a guy get to stop ? There is a lot of drag at 70 mph too.

[Bill in Houston]

I'm speechless. Cool.

[usedgeo]

This is just pasted from the daily update page to keep this thread together.

I fueled up today. 492 miles, 7.8 gallons, 63 mpg. Scangauge had me at about 61.6. I forgot to write down average speed for the tank. There were 300 miles since the Somender Singh grooves.

Yesterday, I drove back to where I grew up, 75 miles one way, 500 ft elevation change, maintained 61 mph on the freeway. Outbound I had a heck of a time getting better than 52 mpg. I had a slight upgrade and 15 mph headwind. I was thinking of all the ways I would have to eat crow on those grooves. The 90+ temperature was making me sweat too. I had started out with a cold car and that did not help. The trip was a spur of the moment thing. I had been avoiding the freeway for several months. I did have a several mile downgrade that almost saved me. I ended up at about 56 mpg outbond. Of course I had to get back up the hill coming home. There were intersections, stop signs and slow curves for a short distance. The trip back with the hill and tailwind worked out to about 64 mpg. I did not shut off the engine but I did neutral coast on hills where I could. The Today numbers were 59.8 mpg, 55 mph ave, 155 miles. Given the 1.5% error of the scangauge I am still calling that 60 mpg at 60 mph. There is not much margin though. I was running 210 WT and 185 IAT. It came back up the hill, which it had coasted down at 75 mph, at 61 mph in 5th gear at temps of 220 WT and 200 IAT. The grooves do help slightly with the torque thing.

Often times on the way back with the taliwind the load on the engine would get so low that the timing would fall back to no load timing, 18 BTDC with the gph just about .2 or .3 gph above driveway gph for that rpm. I could have used taller gearing for sure. Maybe I should have just bumped it up to 65 mph or better to keep a little load on the engine. I can see why those running like this are installing hand throttles. It would be good to keep enough load on the engine to keep the timing up there at 33-34 degrees. That would be DWL though I guess. It is hard to do with your foot.

After I filled up this morning I did a run out to work and back home. Up to work was 70 mpg and home was 110 mpg. These are personal records by about 10% from anything previous. The TANK currently sits at 85 mpg, 29 mi, 35 mph ave. I know I cannot maintain that but it is still a nice way to start the tank.

Gee, this is almost as good as those guys on the TOP ten list . I still feel like an imposter there. This site made it very easy for me to achieve what I have in what seems like a pretty short time.

I have convinced my self of the groove effect. Even though it took me two days to get the grooves in if I could find some hypereutectic flat top pistons I would pull the engine apart again. I think it could use about 10.5:1 compression ratio and about 1 tooth retard on the cam.

Incidently After 2.7 hour without alternator I still had 12 volts while loaded. I have a large deep cycle battery in the trunk. If I do this again I am going to unplug the running lights though.