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Message started by Super Thumper on 02/10/13 at 15:04:11

Title: Overheated engine pics
Post by Super Thumper on 02/10/13 at 15:04:11

This is what an engine head and cam looks like when it has been overheated. This engine came to me like this...it was running poorly...took it apart and this is what the cylinder head looked like.

More pics here:

http://acimg.auctivacommerce.com/imgdata/0/3/3/7/8/0/webimg/6797855.jpg

The exhaust valves & stems are white from excessive heat and the valve guides are probably worn out.

http://acimg.auctivacommerce.com/imgdata/0/3/3/7/8/0/webimg/6797851.jpg

The exhaust valves & stems are white from excessive heat and the valve guides are probably worn out.

http://acimg.auctivacommerce.com/imgdata/0/3/3/7/8/0/webimg/6797847.jpg

The cam lobe is galled either from excessive heat or low or poor oil.

This can all be fixed but it ain't cheap...needs new valve guides, seats, valves, springs, keepers, locks,seals.... resurface the head (it is warped) and a new coat of black paint and it will be ready to go.

This is why you should change your oil and filter regularly! I run synthetic oil because of the superior heat handling qualities...doesn't break down as readily under hot conditions like this.

Title: Re: Overheated engine pics
Post by mpescatori on 02/11/13 at 02:00:03

Interesting...

This could be the opportunity for a "big valve" job + stage 1-2-3 cam.

So, experts out there, what valves would any of you recommend for a valve job ?

:)

Title: Re: Overheated engine pics
Post by Oldfeller on 02/11/13 at 04:57:54

Really? You want the experts to speak on the pictures shown? Heck, that would spoil all the fun you guys are having.

I'll speak to the "cam spauling" shown. I'll let others speak to the white valves (which are pretty much normal looking for a stock EPA lean engine).

http://acimg.auctivacommerce.com/imgdata/0/3/3/7/8/0/webimg/6797847.jpg

This one is hard to judge from the picture, as you can't tell if it is at the apex of the point of the lobe or the bottom of the opposite side -- the picture angle is sorta tough to interpret. If it is the peak of the point, then it is typical damage from low ZDDP oil and is unfortunately commonly found in our engines. If this is lobe peak, then this is ZDDP damage in its infancy, it can get a lot worse than this before the valve train loses any functionality.

If it is the round bottom of the cam form, then it it a different story completely. Remembering that the cam blank is a case hardened mild soft (tough core) steel investment casting so the original surface is pretty rough all over, as you can note from the undressed portions. So perhaps what you see (if it is the bottom surface of the cam form) might appear to mebbe be a lack of clean up in the grind job.

(I'm never that lucky, for me it would have to be the lobe tip for sure)

If it were located up on the tips of the lobes it would be of budding concern, but if it is the bottom then since the cam tappet follower is "up in the air" when it goes past that bottom portion of the cam then the effect of the dimples shown would be pretty much minimal.

A picture of the rocker tappet flat surfaces would be right nice, it would help tie down what is what with the source and extend of potential damage to the engine's total valve train. If that is a tip shown, it has some rocker tappet damage to match up to it ....

I'd be curious how big the "scrubbed" flat spots in the center of the tappet have grown to be in XXXX miles, as that is of interest when people keep asking why we insist you need 1,200 PPM of ZDDP or more in your engine oil to keep that sort of stuff from happening.

As for the head not being flat, that too is common enough. They start out flat and the jug and the head warp together due to heat expansion contraction over time. Our 3 steel plate spring lip rubberized head gaskets are designed to handle some warpage, but I always take a big single sheet of medium course sand paper and reflatten my jug surface and my head surface. The soft aluminium head surface cleans up very quickly and you actually wind up matching up the jug top surfaces to the steel ring of the barrel, removing any high aluminium spots. Easy does it on the jug surface, in other words.

I see no pics of the aluminium cam bearing journals in the head and cover, these would allow us to judge the oil volume and pressure delivery in the engine. Previous owners often set the idle speed too durn low, it should always be 1,000 rpm or higher to provide good oil pressure to those critical soft aluminium bearings.

I'd take the head apart and measure the valve stems and guides and if they were in service spec I'd lap them back in and run them. Remember, our exhaust valves always run at a dull red heat all the time and white valve stem and tulip deposits from the current unleaded gasolines are VERY common.

"Needs new valve guides, seats, valves, springs, keepers, locks,seals ...." might be service spec unnecessary and kinda spendy as the condition of the head is still pretty much normal looking for an EPA lean stock engine.

Title: Re: Overheated engine pics
Post by Super Thumper on 02/11/13 at 07:33:12

The damage shown is on the very tip or peak of the cam lobe.

Title: Re: Overheated engine pics
Post by Oldfeller on 02/11/13 at 08:07:58

Sounds like you are no luckier than I am -- I've already done my original cam that way (yup, car oils) and am I am sure enough starting to do it on a Webb Cam Stage 2 (why I thought the Webb Cam would be immortal, I dunno -- it has a lot more lift and it turns a lot more RPM than the stock cam ever did). Yup, and I had like 4x the amount of tip damage on my stock cam than you have gotten so far on your stock cam.

Oil is important, of all the bullet proof synthetic oils that pour straight out of a bottle the Mobil 1 V twin (as currently formulated) would likely be the best of the bunch for protecting a Webb Cam. Trade-off is viscosity, the 20w50 weight will lose you some horsepower due to viscosity piston drag but it will protect your cam and tappets better due to very high ZDDP levels (1,600 ppm). Remember, 20w50's were Harley spec'd as dino oils that actually thinned out a good bit when they got hot -- and the new synthetic oils don't thin out very much a all at high temperature, so they create a little extra drag on the engine accordingly.

But they do a really good job of protecting them flat tappets and cam lobes.

Title: Re: Overheated engine pics
Post by verslagen1 on 02/11/13 at 08:45:51

I'm trying one of these as a oil temp gage...

http://www.trailtech.net/media/press_releases/tto/72-ET1_sensor_w340.jpg

The cable is a little short as I've attached it to the forward facing oil port.
The 14mm size fits tightly on the plug.

Even on a cold morning it's reading 197°F and 209°F on the way home.

Title: Re: Overheated engine pics
Post by Super Thumper on 02/12/13 at 08:50:25

The engine damage in question was not from my engine but rather one belonging to an unlucky customer :'(

Title: Re: Overheated engine pics
Post by Oldfeller on 02/12/13 at 16:18:03

What did the customer bring it in for, ST?

Title: Re: Overheated engine pics
Post by hexnut on 02/13/13 at 06:49:23

gone fishing

Title: Re: Overheated engine pics
Post by Super Thumper on 02/13/13 at 08:49:39

The customer was complaining of low power, backfiring whenever he rolled off the throttle. poor fuel economy. If you can see the spark plug it is bright white indicating the engine was running very lean...I am surprised it didn't burn a valve or the piston which by the way was covered with a thick layer of carbon. This bike has the stock carb with a cheap aftermarket slip-on Harley Sportster style muffler which sounds like there is no fiberglass packing left in it. The plug is still there blocking access to the carb's idle mixture screw...haven't checked the carb jetting but I will bet it hasn't been changed from stock. It still shouldn't be running this bad though.

When I first got my Savage I did the same muffler swap with ok results and I eventually drilled out the mixture screw plug and open the screw up a little bit and that got rid of the backfiring and also gave me a little better throttle response. I did check the spark plug color after the mixture adjustment and it was a light tan color which is ok.

Something else was going on with this customer's engine to get it that hot. My guess is it was run with low oil or way too long between oil changes.

Title: Re: Overheated engine pics
Post by Oldfeller on 02/13/13 at 08:56:18

Based upon VOA's done on the reformulations of the two Mobil 1 oils we can actually use, both Mobil 1 V-Twin 20w50 and Mobil 1 Motorcycle Racing 10w40 are now currently on the approved list in Tech Section.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1344471565

As always, since Mobil 1 will reformulate without telling anyone so we will always look at them every time a new oil specification pops up.

The new specification SO (or SP depending on if they skip the SO as confusing) has already been "preliminary sent" to the oil industry with a proposed implementation date later on this year. Bob's and other oil boards have already said it is more restrictive than ever before, so we are not looking forward to it at all.

We are down to two $10 a quart motorcycle oils and two $5.00 a quart HDEO oils that will work in our antique valve train bikes as poured from the bottle.

Title: Re: Overheated engine pics
Post by Super Thumper on 02/13/13 at 09:02:19

EXCELLENT...........thanks so much for this info...I have been using Harley V-twin 20-50w oil in mine.

Title: Re: Overheated engine pics
Post by bill67 on 02/13/13 at 09:03:07

#3 Mobil One #2 Amsoil #1 Koltz You'll never have a problem with these Premium Motorcycle Oils. They cost more and theres a reason.

Title: Re: Overheated engine pics
Post by verslagen1 on 02/13/13 at 09:12:33

514F464A444B574C4D230 wrote:

Not all sportster muffs are the same, especially if they've had the center baffle knocked out.
Carbon on top of the piston is probably from burning oil. The savage does this nicely with hardly any smoke. Your suspicians are probably correct that it's been run low on oil, as this indicates it was using a lot of oil. And since it only holds 2 qts, it does kinda sneak up on ya rather quickly.

I'd replace the rings at least. As the cam is damaged, I'd send it to Webcam and get a regrind. rejet and he should be happy.

Title: Re: Overheated engine pics
Post by Oldfeller on 02/13/13 at 09:30:11

What were his compression numbers like when you checked it?

How many miles were on the bike when his "whatever happened" event happened?

And just fer good 'ol brother Routy, and just because he hasn't been paranoid enough lately, is the bike still running the stock vac petcock ??? We think we thinks we knows it lacks the white spacer mod, too.

Arg, matie, me thinks me smells a petcock jest a poopin' inta the bilges again, leaking suck and dribbin' troubles again .....

The customer was complaining of low power, backfiring whenever he rolled off the throttle. poor fuel economy. If you can see the spark plug it is bright white indicating the engine was running very lean...I am surprised it didn't burn a valve or the piston which by the way was covered with a thick layer of carbon. This bike has the stock carb with a cheap aftermarket slip-on Harley Sportster style muffler which sounds like there is no fiberglass packing left in it. The plug is still there blocking access to the carb's idle mixture screw...haven't checked the carb jetting but I will bet it hasn't been changed from stock. It still shouldn't be running this bad though.

Title: Re: Overheated engine pics
Post by Super Thumper on 02/13/13 at 11:18:22

I didn't check the compression since the owner wanted me to rebuild the engine....stock vacuum petcock was in place and apparently working fine. Remember this bike came to me in the middle of January and I didn't ride it far, less than a mile in 15 degree weather. Engine mileage was a little over 32,000. The owner is checking his budget and deciding whether he wants the High Comp Big Bore Kit and ported head. Since the cam & rockers need to be reground anyway he is going with a performance regrind.

Title: Re: Overheated engine pics
Post by Oldfeller on 02/13/13 at 19:54:22

Do not leave the stock vac petcock on the machine -- a big piston and hot cam and opened up exhaust and intake mean you put a Raptor on it 100%.

Stock petcock depends on vacuum levels that will not exist on that modded engine any more. And the modded engine will require more gas than a stock vac petcock will deliver at all speeds and intake vac conditions.

======================

If the bike has 30,000 miles on the clock, those cam lobes look positively cherry compared to most of what I have seen with not quite that many miles on them.

Title: Re: Overheated engine pics
Post by Super Thumper on 02/13/13 at 20:00:38

OK.....thanks for the info....a raptor petcock it will be.

Title: Re: Overheated engine pics
Post by Dave on 02/14/13 at 05:27:22

So.....What makes you think the engine was overheated as stated in the title? I don't see any burnt valves, scorched piston or cylinder, trashed bearings? I see an engine with a lot of miles on it, and one that possibly didn't get the oil changed regularly and got some wear as a result. It might have been running a bit lean.....but overheated....I am not sure?

Title: Re: Overheated engine pics
Post by Super Thumper on 02/14/13 at 06:28:14

I have seen this many times in the past. That white color of the exhaust valves and the bright white spark plug tip is a clear indication of excessive heat due to a lean running engine...remember lean running engines run hot and this one was clearly run lean & hot. When I took my own engine apart this winter the valves were a dark gray color, the spark plug was a light tan color indicating cooler running and proper jetting.

Title: Re: Overheated engine pics
Post by Super Thumper on 02/14/13 at 06:43:34

Also, the piston top had a LOT of carbon buildup, the piston skirts were a little scuffed but not bad, the cylinder walls were NOT scored, the cam bearing surfaces in the cylinder head were not damaged.....there was nothing to indicate it had been run low on oil OR that the oil had been run way beyond its normal change interval. I will be 63 on Sunday, I have been working on engines since I was 15 years old and in my experience I think this engine was run hot but not to the point of mechanical failure. I hope this information helps someone determine what they see in their engines in the future. If and when I get an engine in my shop that has different characteristics I will post some pics like this to help folks understand what they are seeing inside their engines.

Title: Re: Overheated engine pics
Post by Dave on 02/14/13 at 07:10:03

I guess that what the confusion I had with the title.....the engine had not failed as a result of running lean.....or hot.

The Savage as jetted from the factory makes white exhaust valves, and the majority of them run this way without issue. THe only way that this changes is when the owner or dealer pulls the brass plug and makes an adjustment, and/or does some re-jetting. Stock the bike just motors along running lean for miles and miles and miles.....but when the owner changes to a free flowing muffler or puts on a clamp on filter......then the lean condition can get excessive.

Yep......I saw the white valves and white exhaust port and I agree that if I tore down a motor 10 years ago and saw this....I would have been spooked. On the Savage....it is not unusual.

Title: Re: Overheated engine pics
Post by Oldfeller on 02/14/13 at 07:25:22

Ah, Suzuki you little devil you .... EPA leaned on you and in response you set our bikes up to be super lean running critters to make the US gov'ment happy.

You traded off our long term engine life so you could sell an obsolete design in a super lean condition for what, 20 more years?

The engine fooled you though, it could take it.

ST, don't get mad -- all the lean/hot symptoms you saw are real and they exist in all of the stock Savage bikes all of the time. My spark plug looks like white death every time I looked at it and my exhaust valves still are always white on stem and tulip.

I spend a lot of time (and some money) to get back the 10% performance that Suzuki traded off to the EPA, and I got it all back and more at the cost of really poor gas mileage compared to the old stock engine/carb set up.

And ST, how could you / how should you know that the guts you took pictures of are normal enough looking guts? What crazy company would ever DO that to their product on purpose, and then to add insult to injury put a solid brass plug over the carb adjustment screw so you CAN'T rectify it?

Certainly no German company would do that ....

Ah, the Savage. Needs to be tweeked to run at full power and has to have special selected oil to live a full life. It isn't very fast nor is it very powerful for its displacement, but it has good torque and fits old creaky legged old men just fine.

That's why we loves it so ...

actually, we loves it for what it does up in the mountains where it is in its natural habitat. Can't go over 85 mph up in the mountains on even the longest straight away and the torque will blast you out of a corner faster than most all the bikes up there, save the crotch rockets which are GONE so fast you didn't even really notice them blow past you.

Title: Re: Overheated engine pics
Post by Super Thumper on 02/14/13 at 18:39:01

I see said the blind carpenter as he picked up his hammer and saw! The first thing I did when I bought my Savage was to drill out the brass plug and adjust the mixture.....the backfiring departed and better throttle response arrived. Something I learned way back in the 70.s when Uncle Sam made the car manufacturers put plastic caps on the carb idle mixture screws. There's an old Irish saying......fool me once, shame on you....fool me twice, shame on me ;)