Stroker: Titan Engine: My Story

[markw]

Re: Stoker: Titan Engine: My Story

How's your radiator too? A known good radiator is a good idea when your dropping that much coin on a stroker.

 

[TomMcD]

Re: Stoker: Titan Engine: My Story

You've got pressure at the fuel rail but do you know you're getting fuel into the engine?

Turn the engine over by hand (wrench) with the valve cover off and visually confirm the valves are opening at the correct part of the stroke.

Check the various sensor plugs, especially the CPS. Check your fuses. Check for codes if you can.

Best of luck.

--Tom

 

[bcmaxx]

Re: Stoker: Titan Engine: My Story

And the rotor should be just past the #1 cap terminal at TDC.
Let us know what your compression #s are. Maybe you're cam is not degreed correctly???

x2,but it should still start and run

 

[corbinafly]

Re: Stoker: Titan Engine: My Story

x2,but it should still start and run

Not if the cam is somehow waaaaaayyyyy off. Doubtful, I know, but..............

 

[mhead]

Re: Stoker: Titan Engine: My Story

27-APR-2008

corbinafly
Yep there's a preload. Installation of the roller rockers is to adjust until all mechanical lash is gone, then add 1/2 turn for preload. Done.

Compression on a cold motor at wide open throttle with all plugs out and fullly charged battery (in psi)

1 - 150 to 175 peak
2 - 150 to 175 peak
3 - 150 to 175 peak
4 - 150 to 160 peak
5 - 145 to 150 peak
6 - 125 peak

I think that if the cam were mis-timed the engine would clash or the compression would fizzle. #6 is somewhat concerning but this engine is cold and hasn't been run in 3 months (I hate to think about how long it's been) so maybe I've got a ring leak because of no oil.



slipslap
Yes I agree that a stock cam makes no sense. I had read here at that the hotter cams had wear-out problems and I didn't want those so I thought I'd sacrifice a little power. But it was the wrong decision since the stock cam apparently allows the engine to draw more air. ??? I understand why the stock cam has more static compression since it closes the intake valve earlier. A 'hotter cam' closes later with the effect that in a compression test the 'hotter' cam allows some of the air drawn in to escape back out the intake valve as the compression stroke begins. This is why I saw 200 psi in my static compression tests. Why does a 'hotter' cam give more power...? Got me.

xj2win
Good idea. I'd rather not have to hunt for fluky things just yet. Since the engine ran prior to this head, manifold, rocker, and cam swap odds are that the problem has something to do with things I've fooled with.

housemaster0630
I was instructed to do this by Titan when I originally purchased the engine. I did this from the start. I've also purchased a Hesco adjustable pressure regulator and intend on putting it in if required. I have installed a wide band air/fuel gauge and can now evaluate the average fuel ratio thru the motor. Titan suggests the reason the valves bent is that the cylinders ran lean. Won't get caught again although the air/fuel gauge only gives average air/fuel. If one cylinder runs rich then a different cylinder could be lean. I returned the injectors to there supplier for retest. They say injectors 'tested fine' but they were kinda flakey under questioning and I suspect they didn't test, but I tried to cover that base anyway.


markw
Yes, my longer-term worry is that the engine will run hot. Radiator is about 3 years old and has been flushed once. It's all metal 3-core.

TomMcD, bcmaxx
Yes have several times reviewed valve sequence. There is a spark so I'm guessing CPS is ok and the engine ran prior to this head swap. I just did a compression test and can smell fuel so injectors are probably going.


corbinafly
I checked cam installation 3 seperate times using two methods. I knew that eventually I'd doubt myself. - Your intuition about the distributer was correct however. I tossed it in but now that it doesn't start I'm checking everything. I have a FSM and have today carefully revieded installation of distributers. FSM says mark distributer housing at *left* edge of #1 tower on cap. This is later than #1 tower center. Then FSM says install distributer with engine at #1TDC so that the *trailing* edge of the rotor electrode is at the mark. Which means that the electrode is effectively really advanced at TDC. Well this doesn't make any sense to me since I would think it should be centered.

But the bottom line is that I installed distributer as instruced by FSM and engine now starts. I'm about 3/4 of the way thru the 20 minute 1500 RPM cam break-in now but had to stop motor to let it cool. Motor is running on 5 cylinders so I've got some hunting to do. I'm guessing a injector wire or injector.

Thanks for all the suggestions. The true power of the internet! Really great to have alternative views to evaluate. Too easy to become fixated on a problem and be blind-sided!

Mike

 

[xj2win]

Re: Stoker: Titan Engine: My Story

Congrats, I know it feels great to get a motor running after hard work and frustration.

 

[gradon]

Re: Stoker: Titan Engine: My Story

Good job w/ the troubleshooting and good luck fine tuning it. So the difference was all b/t the rotor being centered vs the rotor being on the trailing edge?

 

[mhead]

Re: Stoker: Titan Engine: My Story

Good job w/ the troubleshooting and good luck fine tuning it. So the difference was all b/t the rotor being centered vs the rotor being on the trailing edge?

Hard to believe but yes. Guess the FSM instructions should be followed to the letter. They are quite clear. I was just lazy.

The story continues...

Compression check of warm engine

#1 thru #5 175 PSI peak
#6 162 PSI

So #6 is a little soft. Don't know what this portends.

Engine idles somewhat rough. Pulled plug wires one at a time but am not able to connect rough idle with any one cylinder. Maybe the 'hotter' cam is the cause? I could have an intake leak and haven't searched.

Engine gets hot up to nearly 250 (deg F) in cool air so I am worried it is back to overheating. But it is difficult to get a full load of antifreeze into a jeep motor so I'll hold judgement until after a few heating/cooling cycles that will draw in the full load of antifreeze. There could still be bubbles in the engine.

If you read back a few pages you'll see that the cause of the bent valve was heat and that Titan proposed that the engine ran lean. I have now installed a wide band air fuel gauge and today was the first test. At normal throttle the new gauge indicates a reassuring 14.7 the proper ratio. Under heavy throttle the gauge drops into the 11 range as expected. Wide open throttle should really gas the engine. At no time did I see the engine run lean. Guess my Hesco adjustable fuel pressure regulator can simply stay in its box on the bench. The 24# injectors seem able to handle fuel supply under WOT. And these measurements reject the lean running idea.

So maybe the heat results from the ping I observed. It really pinged. My explanation is that the factory cam draws too much air into the cylinder (see my compression testing results of 200 PSI previously) The current 175 PSI observation with the new hot cam is consistent with go-jeep and others. I've put go-jeep's cold plugs in the motor and so far thru only maybe 2 miles in cool air haven't heard a ping. I don't recall what octane gas is in the tank right now. Fingers crossed Marcus!

So maybe my Titan engine problems can be written down as my requesting the factory cam. Titan didn't have experinece with this cam. Maybe nobody realized that the factory cam would breathe too much.

If coolant is the heat problem now and if the engine cools off once the coolant is all in then maybe there's light at the end of this long dark tunnel.

On the positive side the 4.6 liters, cam, and new manifold have given me a jeep that can only be described as hauling ass. Maybe I'll get more than 2500 miles this try.

Mike

 

[corbinafly]

Re: Stoker: Titan Engine: My Story

...........
If you read back a few pages you'll see that the cause of the bent valve was heat and that Titan proposed that the engine ran lean. I have now installed a wide band air fuel gauge and today was the first test. At normal throttle the new gauge indicates a reassuring 14.7 the proper ratio. Under heavy throttle the gauge drops into the 11 range as expected. Wide open throttle should really gas the engine. At no time did I see the engine run lean. Guess my Hesco adjustable fuel pressure regulator can simply stay in its box on the bench. The 24# injectors seem able to handle fuel supply under WOT. And these measurements reject the lean running idea.

Mike

You're running way rich at WOT as I suspected you would with 24# injectors. One of the most widely spread misconceptions is that you need 24# injectors. My guess is that you would have been fine with 21 or even 19 #ers. I've been running 21# Accels in my 4.6 and at first was running way rich too. But instead of changing injectors, I just had my unichip mapped to adjust for it. People think that the pinging is caused by running lean, but a lot of the times with our "budget" strokers there are other causes for the ping. Mainly compression and quench. And maybe that's why you may need to run so rich to avoid ping.

In a properly setup n/a stroker you should aim for around mid 12s to low 13s for A/F ratio at WOT. That's where you'll make most power without running too lean. I'm running around the low to mid 13s at WOT with more spark advance and no pinging.

 

[gradon]

Re: Stoker: Titan Engine: My Story

Corbin said exactly what I was gonna say: Your WOT is too rich--it should be in the mid-high 12's, so you should install an adjustable MAP and turn the voltage down a bit until your wideband tells you so. Your compression on 6 isn't critically low, but I would continue to check it every 2 mos. or so. You still need to break her in, so the temps should come down(unless there are other issues @ hand--at least it's not due to a lean condition) once the parts start wearing in.

 

[mhead]

Re: Stoker: Titan Engine: My Story

Corbin said exactly what I was gonna say: Your WOT is too rich--it should be in the mid-high 12's, so you should install an adjustable MAP and turn the voltage down a bit until your wideband tells you so. Your compression on 6 isn't critically low, but I would continue to check it every 2 mos. or so. You still need to break her in, so the temps should come down(unless there are other issues @ hand--at least it's not due to a lean condition) once the parts start wearing in.

Thanks for advice on A/F = 11. I'll mess with the MAP but it will be a month or so. For now I want to just drive the thing and see what major problems I encounter.

As for break-in, the bottom end has 2500 miles on it already. I would expect that the roller rockers generate less friction than stock so the top end and cam I just installed should run cooler if anything. I'm really sensitive to heat since my mission is to load my XJ heavy and drive interstate highways across deserts in summer. Such is camping in California in August. I drove 7 miles this morning in 68 (deg F) air and the engine stayed thermostated. If I'm not driving the stroker hard the thermodynamics would seem to indicate the stroked engine should not generate more heat than stock. I understand if I demand more power from the stroker then I'll generate more heat.

The previous build stroker (bent valve) pinged so maybe this is why it ran hot. So my fingers are crossed for now. I intend to drive hot conditions next weekend as a test prior to a Utah trip in two weeks.

Thanks for A/F advice. I'll put a MAP project on my list.

Mike

 

[mhead]

Re: Stoker: Titan Engine: My Story

You're running way rich at WOT as I suspected you would with 24# injectors. One of the most widely spread misconceptions is that you need 24# injectors. My guess is that you would have been fine with 21 or even 19 #ers. I've been running 21# Accels in my 4.6 and at first was running way rich too. But instead of changing injectors, I just had my unichip mapped to adjust for it. People think that the pinging is caused by running lean, but a lot of the times with our "budget" strokers there are other causes for the ping. Mainly compression and quench. And maybe that's why you may need to run so rich to avoid ping.

In a properly setup n/a stroker you should aim for around mid 12s to low 13s for A/F ratio at WOT. That's where you'll make most power without running too lean. I'm running around the low to mid 13s at WOT with more spark advance and no pinging.

Thanks for A/F advice. See other reply. You say above 'more spark advance'. Well this puts you amoung the brave with a ping prone stroker. A couple of questions:

How did you arrange advance? Unichip I guess? Does my '92 have such a thing?

Stroker build: There's a cool spreadsheet somewhere that gives build parameters. I'd love to know the static measurements in your engine that you can run advanced. I'll try to remember the list here:

I assume you have the 4.2 rods/crank?

Head gasket thickness (inch):
Head decking (inch)
Head cylinder chamber volume (cc):
Block decking (inch):
Piston pin height(inch):
Piston dish (cc)
Quench height (inch):
Static compression:


Piston type:
Cam type:
Spark Plug type:
Fancy valves, rockers:


Seems to me that there's a lot of different ways to build a 4.0. Sometimes there's a thread here at like "show me pictures of ..." Wouldn't it be nice to have a stroker thread where a standard set of questions about the build details are answered and then a statement of the experience with the results is given. This would help I think in choosing a plan or manufacturer. Maybe something like this already exists?

The reason I ask is that Titan's quench height in my motor is something like 100 mills (0.1 inch) which is much over the 74 mills stock. Later it will be nice to explore quench height in more detail.

Thanks for A/F advice!

Mike

 

[corbinafly]

Re: Stoker: Titan Engine: My Story

Thanks for A/F advice. See other reply. You say above 'more spark advance'. Well this puts you amoung the brave with a ping prone stroker. A couple of questions:

How did you arrange advance? Unichip I guess? Does my '92 have such a thing?

Stroker build: There's a cool spreadsheet somewhere that gives build parameters. I'd love to know the static measurements in your engine that you can run advanced. I'll try to remember the list here:

I assume you have the 4.2 rods/crank?

Head gasket thickness (inch):
Head decking (inch)
Head cylinder chamber volume (cc):
Block decking (inch):
Piston pin height(inch):
Piston dish (cc)
Quench height (inch):
Static compression:


Piston type:
Cam type:
Spark Plug type:
Fancy valves, rockers:


Seems to me that there's a lot of different ways to build a 4.0. Sometimes there's a thread here at like "show me pictures of ..." Wouldn't it be nice to have a stroker thread where a standard set of questions about the build details are answered and then a statement of the experience with the results is given. This would help I think in choosing a plan or manufacturer. Maybe something like this already exists?

The reason I ask is that Titan's quench height in my motor is something like 100 mills (0.1 inch) which is much over the 74 mills stock. Later it will be nice to explore quench height in more detail.

Thanks for A/F advice!

Mike

Spark advance and fuel mapping it done with the unichip. It can be added to your 92.
My stroker was built by hesco with zero deck height so the quench is about .043". The static compression is 9.42:1 and it's got their h264 cam with performance springs in it. Forged pistons, 4.2 crank, 4.0 rods.

 

[SourApple]

Re: Stoker: Titan Engine: My Story

Good job w/ the troubleshooting and good luck fine tuning it. So the difference was all b/t the rotor being centered vs the rotor being on the trailing edge?

glad it worked out for you..

i dont mean to interrupt your thread but i think that i am having a similiar problem, can someone explain this to me.^

by the way was is "FSM"? thanks

 

[IH392]

Re: Stoker: Titan Engine: My Story

I'll put my two cents in, I built a low compression stroker and it was also heating up extremely fast with the 24 lb injectors. I had problems with engine flooding from the heat soaking into the injectors. So I put my stock injectors back in, and now the engine does not heat up so fast, and the performance feels the same. I don't know if it's running lean at WOT, but I don't really care as long as it runs cooler.

 

[mhead]

Re: Stoker: Titan Engine: My Story

glad it worked out for you..

i dont mean to interrupt your thread but i think that i am having a similiar problem, can someone explain this to me.^

by the way was is "FSM"? thanks

FSM = Factory Service Manual

If you've had the distributer out and are replacing it then you will see that the distrib can be replaced with the rotor at many different positions (like the hands on a clock). There is only one correct position. Read further back where I describe the correct positioning. If you have not had the distributer out of the motor and have a no-start there are many other causes and threads that address them.

::: I have a FSM and have today carefully revieded installation of distributers. FSM says mark distributer housing at *left* edge of #1 tower on cap. This is later than #1 tower center. Then FSM says install distributer with engine at #1TDC so that the *trailing* edge of the rotor electrode is at the mark. Which means that the electrode is effectively really advanced at TDC. Well this doesn't make any sense to me since I would think it should be centered.

 

[SourApple]

Re: Stoker: Titan Engine: My Story

i did have it out. changed the cam also. i was reading earlier in this thread that you put the rotor to the keft of the post of number one cyl on the cap vs. actually in line with the post of number 1... right

 

[mhead]

Re: Stoker: Titan Engine: My Story

i did have it out. changed the cam also. i was reading earlier in this thread that you put the rotor to the keft of the post of number one cyl on the cap vs. actually in line with the post of number 1... right

Just edited above


::: I have a FSM and have today carefully revieded installation of distributers. FSM says mark distributer housing at *left* edge of #1 tower on cap. This is later than #1 tower center. Then FSM says install distributer with engine at #1TDC so that the *trailing* edge of the rotor electrode is at the mark. Which means that the electrode is effectively really advanced at TDC. Well this doesn't make any sense to me since I would think it should be centered.


FSM has good sketches of the above descriptions. I was wierded out by the *left edge* instruction sice I figured it would be at least centered. But the sketch was quite clear. Left edge of the tower, or a few degrees later than tower center. Wierd. And then the *trailing* edge of the roter making the rotor electrode width all pass by the tower center when the engine gets to #1TDC. Weird.



Yes, I did originally install distrib at what I thought was correct, rotor electrode centered with #1 tower. But engin didn't start. Weird thing was that the #1 plug when removed from cylinder did show a spark. I guessed at the time that this meant I should at least hear a bang. So follow the FSM instructions to the letter. Also not on this thread but others report that on some replacement cams the distributer can NOT be installed correctly. The cam gears leave it too far one way or the other when the engine is at #1TDC. In this case the little tabs on the distributer housing must be cut away so that the housing can be rotated to match the rotor position as forced by the cam gears.

 

[89xj]

Re: Stoker: Titan Engine: My Story

i did have it out. changed the cam also. i was reading earlier in this thread that you put the rotor to the keft of the post of number one cyl on the cap vs. actually in line with the post of number 1... right

you need tdc on the compression stroke, not the exhaust stroke or you be 180 out. take spark plug out, turn crank clockwise and feel for the compression stroke and align small notch on harmonic balance to zero on timming scale. on my 89, there is a small notch on the harmonic balance thats hard to see.

 

[xj2win]

Re: Stoker: Titan Engine: My Story

The same thing happened when I was installing my distributor and I had a hard time coming up with an explanation. The only thing I could think of is that the electrode is on the trailing edge of the plug at TDC because it is just ending the spark sequence. By the time the piston is at TDC the fuel should already have been ignited, so the spark has to occur ever so slightly before the piston hits TDC. Also take into account the spark has to go from the electrode through the wire and plug. There's minimal resistance, but it does take a very small amount of time.