Finally got my 615 on the dyno yesterday and the day was well not quite as expected. First few pulls we ran it up to 6500 rpm looking to get timing and fuel best for max torque. Made 4 pulls to 6500 and stacked the rings up on the exhaust side at the wrist pin on #6 piston. It got real hot and started to melt the piston and locked the rings up in that area of the piston.

here's the setup:
4.626 stroke, 4.600 bore, 6.750 rod lenght, wiseco Q8 pistons, 15.5:1 compression, 043/043/3mm rings, dart 20 degree heads, titanium valves, dart tunnel ram, enderle hat, k-valve, 39 nozzle jets, started with 90 main pill, timing was at 30 for first 2 pulls. Enderle 80A-1.

Motor had an oil leak out the rear main seal/oil pan area during every pull and every run on the dyno. Moroso 4 vane vacuum pump spinning at 60% of crank speed with releif valve set to open at 10".

Initial run in was with gasoline rons primer plus system to seat rings and build some temperature. Checked over the valves and started dyno pulls the following day.

First pull was 90 main pill, 30 degrees timing and 39 nozzle jets. Made 885 tq and 1029 hp sounded fat and had some holes in the dyno numbers on the way to 6500. 97 psi fuel supply pressure, -1.2" vacuum crank case pressure.

Second pull 100 main pill, 30 degrees timing, 39 nozzle jets, made 885 tq and 1032 hp at 6400 rpm. 77 psi supply pressure, -2.5" crankcase pressure. Was smoother in the pull but still heard a few bobbles, but didn't show in the numbers.

Third pull 32 timing and 100 main. 892 torque, 1039 hp at 6300 but bobbled some at 6400 down to 997, then back to 1013 at 6500. 77.1 psi fuel pressure, -4.4" vacuum crankcase pressure.

4th pull 32 timing, 95 main, hp fell off, toque fell off didn't even print out the sheet. Noticed lots of smoke coming from the vacuump pump check tank. Shut it down and started looking at things. #6 was showing 60 psi compression and 100% leak by. All other cylinders showed 180 to 190 psi.

Tear down shows all the head gaskets were sealed up no issues there, but #6 piston has started to burn down to the wrist pin on the exhaust side of the piston. All 3 rings are locked into the piston and theres evidence of heat and aluminum spray on the cylinder wall between 6 and 8.

A few questions:
What's the max timing people are running on these SR20 headed combos?

Anyone out there using mechanical injection and methanol on one of these SR20 style 600 inch motors? If so what fuel pump and nozzle/main pill combination.

What can cause this?

Can this smaller ring package run well in an injected methanol application like this? Is this a break in issue? Did i not get the rings to seat and started pulling too early?

My guess here is it was too lean on third pull and it hurt itself. Just seems weird to me because i've run several motors in the past 565 and 598 24 degree conventional heads and never had them be finicky when it came to timing or fuel mix. I've moved both timing and fuel around quite a bit and never hurt anything.

Any ideas / help would be beneficial.

Assuming the nozzles are in the ports, did you put in new plugs each pull and take plug readings? EGT temps for each cylinder? Any peppering on the other cylinders?

If you burned a piston without question you have a fuel/ timing issue. Taking plug reading is key to getting the fuel in each cylinder right IMO, cant argue with what the spark plug is seeing. 32* sounds high for a 20* head. My injected 23* head was happiness at 34*. Blower motor likes 28*

I run a 043/043/ 1/16 ring package in my blown motor

This message has been edited. Last edited by: Big Steve,

Did your dyno have O2 sensors? I really think it is important to getting a good safe tune up quickly. Which is really why you dyno anyway it to get a good safe tune up.
Now my motor is a 454 SBC but it does have the thin ring package and it works well with alcohol. Also I can pull over 17inches of vacuum on mine. Also my motor is not set on kill it is more conservative so we are not apples to apples.

Have you checked for a clogged nozzle?
Do you have a high speed leanout or any other things that could change the fuel curve?
What was your water temps during the pulls?

As for timing my motor has the AFR 235 heads which is a 23* SBC head and I was told you need to run 38-40* timing with them. My motor on the dyno runs best at 28*-30* and I think many people run way more timing than they really need. With that said I have made pulls at 38* and it did not lose that much horsepower. Your heads are better than mine and 20* so it may not even need that much.
I to have moved around a lot on fuel and timing and never had any issues.

With out good O2 readings or plugs readings hard to say for sure why. You will have look closely for clues. I do not think the thin ring pack is an issue, I run same ones.

I am going to watch this thread closely as I am considering going to a BBC similar to yours.

Hurting the motor in 3 pulls means to me that your alky injection tune up is not even close.

Also not sure why you choose to swim up stream with your combo! That combo on alky is not kind! I will also add that using a Ron's deal you would likely need a tune up that runs higher pressures (140 - 160) with high speed by passes to get a fuel curve that has a chance.

On timing, I run a Pro 20 632 on gas and run 29 degrees of timing. On my conventional head stuff I ran less timing on alky than gas!

What did the plugs look like after the 1st pull?
.039 sounds small with a .090 bypass imho.

Xxxx

I have always heard bad things about 20 degree heads and injection. Is anyone out there running one with success? If so I would reach out to them for help/guidance. Did you try James Monroe?

The motor combination above will make 1200 horsepower with a gas carb

What are the few Bobbles you say you heard? Could the motor be popping? If so that is camshaft profile. JMO

I suspect its something other than fuel tune. with 39 nozzles and 90 main you should be rich. When was pump lat flowed? Pressure seems low for that setup assuming pump is good a 80A 1 should be just under 7 gpm.

Agree plugs are best indicator. I like EGT's to compare cylinder to cylinder and plugs verify egt's. As for 02 I think using them to get best reading in one cylinder then tuning other to match its egt and plugs is full proof.All three matching is hard to argue.LOL

http://www.fuelinjectionent.com/ Go to tune up calculator,natural aspirated,enter info.Not dead on but dang close.

I have screwed up and ran injected motors way lean for various reasons.Blocked tank vent, bad pump and just tuner screw up and never burn a piston on injection.Now with blower I have burnt a few looking for the to far line.LOL

IMO you are abusing motor for little to no return with 15.5:1 compression. I found that after 14:1 the gains where very minor and tune up lot more touchy.

This message has been edited. Last edited by: wideopen231,

When I was running injection with my 18 deg Duke motor I ended up in the 41n/65p range with a twin gear pump. 26deg timing

"Bobbles" sounded like every other time I had an injected motor on the dyno that was rich. To me it sounded like it needed less fuel. Made a move towards the lean direction and it sounded better, the numbers also stacked up much better on the sheet. That move was 10 numbers leaner with timing at 30. Then moved to 32 and eventually to 105 with obvious negative consequences.

The timing range for me is a question here. I would have thought 30/32 was safe but starting to think timing was too high.

I know the 20 degree stuff is different, but I've never hurt one cause it was lean on injection. I've leaned them out so bad that it wouldn't get to the the shift point and just lay over with no negative consequence to the motor.

I also checked all of the nozzle pills and found no plugging or fouling in any nozzle jets.

Don Gerardot flowed the pump when he built the system.

quote:

Originally posted by Triple Nickel:

quote:

Originally posted by Triple Nickel:


No O2 sensors cause I was running my headers vs the dyno headers so i didn't have the bugs in them. Same thing goes for the EGTs. This isn't my first go at injected big blocks and I really wasn't trying to set the world on fire here, I really wasn't concerned at the lack of EGTS or O2. Im gueasingvthe 20 degree heads +615 CI dont like timing. Lesson learned it will have all the gizmos on it for round 2.

About O2.... what is a good target O2 for this application. Will need to dig up my old dyno sheets to see where I fell out last time but I'm thinking I was around 5.4 ish??? At max power....

A couple of thoughts.
The better the head and combustion chamber design the less timing you need for best performance.

If you are too fat you can run a little more timing and get away with it. But if you are lean and too much timing......

From my experience the EGT are totally useless and I have even removed them from my car. I now run 8 O2 on it.

With out O2 you really should have checked plugs closely after every pull to try to get a good idea what is going on inside before it hurt it.

What about water temps? There should be clues somewhere as to why it happened.

On my O2 I use the gas scale (Does not matter what scale you use it is reading oxygen) but on mine at full throttle best power is 12.9 to 13.1 do not remember where that cross references to on alcohol scale. Even if you were using same scale as I do that 12.9 to 13.1 may not be same on your motor due to calibration? I would have used the same sensors as on the dyno and same calibration for the dyno session. Then dyno operator can tell you with this system and calibration it should be at XX for best performance and safe tune.

That is where a really good Dyno Dude can be a big help. He should have all of the O2 etc and and know what to look for if anything is out of whack before it hurts motor. I am in Dallas / Fort Worth, Texas and there is a bunch of dynos in my area but I go almost 4 hours each way to have my motors dynoed because the guy is good with Enderle injection and good at knowing what to look for to protect your motor and get most out of it. There should be signs and clues before it has major damage and your operator should know what to look for to find them.

My suggestion is to always run dyno headers with O2 to get your tune up. You need all of the information you can get, you are paying good money for it. Once you get the TUNE UP right then you can put your regular headers on to verify and make a pull.

My goal on the dyno is to get a good, safe tune up. Start a little fat and with timing way down. I have same pump as you but much smaller motor so I need a high speed lean out. The dyno and O2 readings also help me to know exactly where to bring it in. Your motor as big as it is may not need a lean out but you will not really know with out the O2 or a lot of time consuming dyno pulls.

I hope this does not sound bad but if you put it on the dyno you need to get all of the information it can give you.
I completely agree with you about not wanting to go to gas carb as for my deal I also run Nostalgia races and run the Enderle hat.

One other silly question, are you sure all of the ring end gaps were right? We are all assuming it is a tune up issue but could it be the ring gaps?

Are the 20* heads no good for alcohol injection? Do not know, have heard that on larger, higher performance motors the gas will out perform alcohol but nobody really knows exactly why. Think it may have much to do with camshaft but that is another subject.

Just my worthless two cents but I would not run that engine on alky. I know some will disagree with me. And yes, I ran injected alky for a long time. I would put the engine on gas. Good luck!

Thanks for all the replies. I agree in theory with everything posted here. Things is on these 20 degree deals there aren't very many piston choices available off the shelf just yet, the dome is the smallest dome available and without stacking a ton of head gasket on it and ruining the quench i couldn't get the compression down from the 15.5 range. I was honestly targeting 14.5 to 15.0 range. Ill just have to stick some more head gasket on it this go around. This is a bracket motor and running a custom piston has caused me some headache in the past with having to wait for 2 months to get another set of custom pistons in for it at rebuild time. I'm not in the business of ordering 2 sets of pistons when i order one as i never know what might happen when it needs a rebuild, therefore shelf pistons were mandatory. This immediately limited my options.

I haven't had luck with similar ring packages (043/043/3MM) on my injected 565 in the past, but figured i did something wrong with ring end gaps and or break in and or hone so figured this go around i would pay closer attention to all that and have a better outcome seeing as how everyone else seems to get away with it. My preference would have been 043/1/16/3/16 but that wasn't available in wiseco with the rod/deck/stroke combo i decided to build. I really like the wiseco pistons and they have treated me well for all of my past builds. This motor may want a different piston manufacturers piston.

Its all a learning process for me here and i set out on this adventure to determine if there is in fact a reason why one of these motors won't make real power on injection and methanol vs. gasoline so all of this is self inflicted. I just never anticipated burning the damn piston up on the dyno pulling it to 6500 rpm trying to find timing and rough in the fuel mix. Just seems very finicky and was wondering if i totally missed something here.

Big Steve.....

No didn't put new plugs. That will change, going to NGK's and guessing i'll have quite a few sets for initial pulls on the syno.

No i didn't really see any indication on the other spark plugs, but i did see indications of etching on the top 1/4" of the bore on several other cylinders along with this one. IE it looks like it was hot all around if this is a good indication. Not sure why the etching shows up on the cylinder and not the plug. Going with NGK's next go around.

Next go around, will be WAY more careful with moves and diagnostics, including plug readings in every cylinder every pull.

My blower 555 liked the timing at 28 to 30 making 15 to 18 psi of boost. Had a crank trigger system get lose on the blower motor once and advanced the timing to (the pickup moved from the top 1/3 to the end of the bracket), i'm guessing somewhere north of 40, made several passes like that before i figured it out. Tore it down and didn't find any issues with pistons, head gaskets looked like they fluttered some but pistons and other gear was all fine. That experience influenced my approach to this motor and provided a sense that it would be more tolerant of higher timing and figured it would show up in the power numbers on the dyno before it hurt itself. I guess i found out the hard way that's not the case.

Thanks for all the input i'll keep everyone up to date as far as progress goes.

I would like to see if things have changed with the alky on the 20 degree stuff and if anyone has had luck. We did the SR20 on a 598. Had the same issues with alky and melting rings. I know of a couple 582 combos running alky that run the same as a conventional headed motor. From our experience when the heads 1st came out I would say your issue is alky in general.

quote:

Originally posted by Bob Payton:
When I was running injection with my 18 deg Duke motor I ended up in the 41n/65p range with a twin gear pump. 26deg timing

Trip,

A normal timing for this combo on gas is 32 to 34 degrees! This may be telling you something as I state above, I run my Pro20 deal on gas at 29 degrees!

When an alky motor gets to 1.80 and above HP/CID you got a bunch of alky going in the cylinders, if its not atomized it won't burn!

Since you are taking on the challenge of this combo, if it where me I'd treat it like a NOS motor, increase quench volume, be very conservative on timing, read the plugs and forget O2 numbers until you back into what you need to run to make it happy. Getting back to the amount of alky you need to make the power this combo is capable of, I feel you need a high pressure/small nozzle setup in order to have a chance at getting all that alky atomized so you can burn it.

Good luck

Mine is a 632, 14.5:1 compression, BC out of the box heads, cam is Duration at .050 =286/298, advertised 326/348. Cam is installed -4 degrees. I have a 0.5 pump and 32/38 nozzles on a 5” enderele system. I have an O2 sensor on the even side of the engine. My pump was flowed at 5.3 gallons at 4000. I run a 100 bypass and record about 10:1 during staging, about 11.5 on the chip waiting for transbrake release and then about 12.5 at transbreak release. All O2 reads are on the gas scale but I am running methanol so it’s just a simple conversion. During the run I remain in the high 12’s going down track. I do not have a high speed bypass as I am marginal with the 0.5 pump.
I cannot see how a 100 main pill could have been lean, but from what you describe it certainly seems it was lean.
As far as power, I have never dyno’d the setup but in a 1975 pound dragster (after a run with me in it), I have run 7.60’s pretty consistently at 179. I have run timing from 30 to 38 degrees and the best seems to be 38. Performance is pretty sensitive to timing for me.