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After cranking compression & leakdown tests, bore scope cylinder and reed inspection, timing check, and several re-jetting exercises, a starting/idling problem with my turbo Johnson was finally resolved. I would have saved several hours work and had more fun if I'd only paid more attention to the "little things" while looking for a bigger problem. Have never seen this in all my years. No external evidence of gas leakage and no carbon traces...just loose! Go figure.
Tim
Never saw that before, good find!
Never had that happen with an NGK but I have had a Champion do that.
What am I not seeing here?
Dopey Jeff
I had one like that in our race bike with an NGK.
A rare occurrence indeed, your is only the second I've seen.
I check em regularly now.
Doh! and double Doh! Never seen an electrode go away like that.
Jeff the Half Blind
Not sure why you're running R plugs unless its necessary for some of your electronics. The R plugs are more fragile and will fail when overheated.
Usually caused by overtightening of plug. Sometimes by plug not being rated for temp or compression that is being exposed too.
Thanks all for your input. The BR9HS was chosen because of successful experience on the race course with OMC & Merc mod engines. The new set installed will be lake tested next weekend. Should there be another failure, another type will be selected. Will conduct research this week just in case.
Tim
Quote:
Originally Posted by hydroplay
Ok Sam,
So much for my history with "R" plugs. It's off to the parts store for some B9HS NGK's. After only an hour's time on the water today, another BR9HS failed (this time with carbon traces) - along with the head gasket. I'm hoping there is no additional damage: Thankfully the pistons look fine!
Last fall, after about 3 hours total operation, the #2 cylinder fire ring blew on the intake side immediately adjacent to the starboard most head bolt. Replacing the gasket at the river, it was immediately difficult to start, but performed well once lit. It was the #2 plug that had the loose ceramic..........
Today, after about a total of 2 hours operation (less than 1 hour on the new plugs), the #1 cylinder fire ring blew, this time on the exhast side adjacent to the port most stud. Yes, the head was studded after last years breach. The question is: Which failed first?
Unfortunately, this time the head was damaged and will require a .010" cleanup cut. Unless the block is damaged, I will make repairs and secure B9HS plugs this week for a follow up test next weekend. Regardless, This winter the head will be oringed.
Thanks again to all that responded. Images tomorrow night.
Tim
Quote:
Originally Posted by Tim Kurcz
As we all know, there is much difference in 2 and 4 stroke engines, and of course a lot of difference between a 2.3 liter Ford 4 banger and what you are playing with.
That said, perhaps an experience I had in the early 80's would be of some help in figuring out how to solve this problem, but I definately think based on my experience with the Ford four you are on the right track.
The 2.3 liter Ford in stock form, without a lot of mods, was really never meant to be run with an overly high compression ratio, either the result of the head just being pulled down tight on a naturally aspirated engine, or forced induction, either by super charging or turbo charging. For that reason when Ford came out with a turbocharged version in the 80 model to compete with some of the BMW's and other factory hot rod's (this also led to a much better version of the motor and car called the Mustang SVO in '84) they tried to keep it simple with a "suckthru" turbo/carb setup which increased the HP about 25-30 over stock. The turbo was limited on boost it could achieve by a mechanical waste gate arrangement. I purchased one for Eileen to drive (and me to play with as her 455 Grand Priz was a gas hog) but quickly found out that it was still lacking what I was used to so found a little more HP was available in a boost kit with alcohol/water injection from an after market supplier.
Standard boost was about2-3 lbs and the kit would allow waste gate adjustment all the way up to about 6-8 lbs depending on how brave you were and how big your pocket book was. Long story short I was replacing head gaskets almost every week until I got smart and went to a better head gasket and O'ringd the block and got some better head bolts so as to be able to hold the increased boost.
I seem to remember from previous posts about this engine that you do have water injection to help alleviate detonation, so possibly the O rings will do the job for you. With the changes mentioned above I was able to go to 6lbs of boost before I had other problems with detonation that caused piston damage, so hopefully this will solve the problems. The O'rings continued to keep the head gasket problems to nothing though. The head gasket I settled on was a very thin soft steel that was able to "form itself" to any imperfections in the mating surface for water/coolant sealing, but the O'rings did the serious sealing compression wise, and the better head bolts also did their part, as the first couple of times we had a problems we did not replace them, and found out they had been stretched past yield and were no good for reuse so they were replaced with a better quality bolt.
I really have enjoyed your posts about both this engine and the 666. Keep up the good work, and above all keep posting about your engine building adventures.
This just in from a photographer buddy....... When you go, go big! A few items to note:
1) Loctite 242 remains on the Grade 8 studs.
2) Badly roached head gasket. Hoping the deck surface is OK.
3) Error in reporting last night. Last year it WAS the #1 cyl., but on the intake side.
4) No guarantee about position for the problematic #2 spark plug from earlier this summer.
5) This time the plug shows carbon tracing AND severe overheat in addition to the displaced insulator.
More images tonight.
Tim
Do you think the head is flexing as they are not overly thick/stiff
How much higher do you think your BMEP is?
Cheers
Thanks for your historical perspective and thoughts Bill. In both cases the engines were asked for much more than they were designed/tested for. If your plugs and head gaskets looked somethong like this, have a chuckle on me. Though a little frustrating, the smiles-per-hour oughtweigh the effort easily: Acceleration is a powerful drug!!! Your 2.3l Ford would be more work to repair, but likewise the results were likely worth it.
Side note: In my career with Loctite, I frequented the Ford Lima engine plant where your 2.3 l turbo was built (and the 429/460 and 300 six). Try as I might, no engine-for-glue trade was forthcoming. It was a strong little engine for sure, a dear friend purchased the first SVO which was great fun. Today, there's a local autocrosser with a highly modified 2.3 turbo T-Bird that runs well in the national point standings running 24 lbs boost!
In my case, there is no cylinder damage short of a few scratches in the #1 (been there all along), the firedeck was undamaged, and the engine is reassembled waiting final torque calculations and a spot of good weather. I'd like to try surface gap plugs, retorque after the first three thermal cycles instead of one, and likely another water bleed at the top. But if the WX does not behave, it may not see the water again till May.
Tim
For Powerabout, I can't begin to guess the BMEP, but will go back to thermodynamic formulas and report findings.
Bill:
What that motor needed was an intercooler! (I'm sure you knew that already.) Also, water cooling the turbo (vs. air cooling) would have helped keep the forced air temperatures down.
Jeff
PS: Drove several of those motors in T-Bird rentals. Solid runners.
Quote:
Originally Posted by Fastjeff57
Actually, charge cooling is accomplished with methanol and 18% castor oil mix injected into the intake stream immediately downstream of the carb which is immediately upstream of the turbo. This enriches the mixture and cools the charge simultaneously.
The cooling problem is limited water jacket volume and that the #1 cylinder gets pre-heated water: Cooling water feeds from the bottom up passing the #3 and #2 on the way up. Your prompt gives me cause to engineer a cold water feed to the top of the block.
Thanks!
Tim
Interesting! GM did something related to that with the later SB Chevys--they reversed the water flow to get more cooling into the center of the block and heads.
Jeff
Quote:
Originally Posted by Fastjeff57
Jeff:
I am sure that would have helped, both performance wise and possibly with the other problem with the head gaskets.
The 80 model I had was the first example (as far as I know) of a turbocharged 2.3 liter four from the factory. Still wanting to have some decent gas mileage with the car she was driving, and running out of patience with the problems with the 80 model, when Ford came out with the SVO model in 84 we purchased one of those. Several differences between the 80 and the 84 was the turbo was a "blow thru" and was upstream of the fuel injectors, where the 80 had a carb and the turbo was a "suck thru" downsteam of the carb. Also the wastegate was electronically operated in conjunction with the engine management computer, and has an in dash control for the grade of gas you are using, because as you might remember, gasoline quality was not as good in the mid 80's as it is now, and if you could not get premium you could use lower octane regular, flip the toggle switch, and it limited the boost so you did not have the head gasket and detonation problems as was common with the 80 model if you exceeded the factory limited boost.
A really good performing car for the time, and almost as fast as the 5.0 V8 and handled much better on the Ozark roads. We still have it, w/about 190K miles and still going great, although not as fast now as the newer models. But after almost 30 years, and excessive mileage, neither am I.
ADD: Tim, i really hope, as I am sure you do also, you get one more ride in the turbo before winter. I really enjoy reading and looking a photos of your interesting projects.
because you need hot bores and cooler heads yet every engine except that one is done backwards for simplicty and hot water goes up easily and not downQuote:
Originally Posted by Fastjeff57
I would not use surface gap plugs until the cooling problem is corrected. The center electrode usually ends up in the combustion chamber instead of in the plug body. Don't know why you chose the lost foam block instead of permanent cast one. The lost foam does not hold shape as well as the permanent. Also the permanent has better cylinder sleeve support and higher crankcase pressure. There are several versions of the lost foam. Depending on which one you are using it may be dumping too much water from the bottom causing lack of water pressure at top. Do you monitor water temp, water pressure and CHT ? That would help you find problem and stop before damage occurs. Good luck.
Whew! That's the best reason ever not to use the surface gap plugs, at least during development. Answers to your questions: 1) The lost foam oval exh port powerhead was available complete with relatively low time. The turbo likewise was a low time dyno piece. I didn't want to invest in high $$$ parts not knowing if the engine would even work - Boy was I surprised! 2) The turbo uses factory water routing (less t-stat) from bottom to top around the cylinders first, then into the head through the t-stat housing, top to bottom, exiting after the head. There's no reason to believe any steam pockets or starvation are occuring. 3) There is no instrumantation except for EGT and boost pressure. The stock 45SS pump has proven robust in all applications and have not measured press or temp. Also, have never run cylinder head (spark plug) temp sensors, but now's a good time - good thinking.Quote:
Originally Posted by Popa Sam
As the #2 & #3 seem stable, it makes sense the #1 might be failing due to pre-heated cooling water. Thoughts are to revise the cooling system entirely using cross-flow for cylinders, and build a stiffer gasketed or O-ring head this winter.
Thanks to all for your thoughts and tips.
Tim
Tim:
Does the switch box on your turbo have a knock sensor? Just curious.
Jeff
PS: Did you know htat Buick came up with these now common knock sensors when they introduced their V-6 Turbo Grand National way back in hte 80s? They also pioneered distributor-less ignition at roughly the same time.
Sorry for the delay...... The turbo uses the standard CD-3 with no rev limiter, no knock sensor. In this case detonation is not the problem (pistons/spark plug electrodes are fine). Closer scrutiny of the whacked head gasket indicates hydraulic crushing and splitting of the stainless steel fire ring, followed by lateral breach and destruction. There does not appear to be a clamping problem. That the failure occurred twice in the #1 tends to indicate the hotter, leaner cylinder might be contributing to the failure.Quote:
Originally Posted by Fastjeff57
The Pro-Marine aftermarket gasket has a wider, possibly stronger fire ring. It is photographed with the damaged OMC gasket and a new OMC gasket. Note the crushed fire ring in the used gasket (yet to split). The deformation is the same on both sides of the gasket. It would be interesting to learn the cylinder pressure but alas, I don't have that type of test apparatus available.
Tim
I thinks its very difficult to get a knock sensor to work on a 2 stroke outboard, lots of noise going on there...
With open deck blocks the cylinders might be moving under high load as well which causes the gaskets to blow.
One of my mates at OMC said this was a problem with the old racing v4 and v6's back when he worked on them