Stroker- Engine kinda stalls at 4K RPM, any thoughts?

[old_man]

The big difference with my stroker is in the low end grunt. Whereas I could pull the Eisenhower tunnel loaded at 55 before, I can do it at 75+ now. All the torque is right at the driving rpms now, throttle response especially around town is awesome.

You have to realize that not all strokers are the same. Compression ratio, cam and header selection will effect the hp and torque curves radically. I built mine for low end and sacrificed the top end. I love it. I don't have to wind it up tight to accellerate, it just does it.

 

[Dr. Dyno]

I sort of felt the same way with my stroker....not as "strokerish" as you would expect after hearing people like Dino speak of these incredible speed #'s.

Maybe I'm just lucky or I built a very good stroker. Remember that you're adding displacement when building a stroker so you've got to port the head to make it flow more air, add a bigger TB, and use a 2.5" exhaust so the stroker can breathe. Otherwise you'll find it runs great up to 4000rpm and then it starts to run out of breath.

 

[Bender]

You're completely right Dino.

I didn't do any of the head or intake work so it really runs out of steam around 3800 rpms.....or rather doesn't seem to have the "kick" most engines do as their rpms get up in the 4k range.

 

[CRASH]

Maybe I'm just lucky or I built a very good stroker. Remember that you're adding displacement when building a stroker so you've got to port the head to make it flow more air, add a bigger TB, and use a 2.5" exhaust so the stroker can breathe. Otherwise you'll find it runs great up to 4000rpm and then it starts to run out of breath.

I have a very nice long rod stroker, ported head, 58 mm intake, header, 2.5" mandrel bent all the way back. Mine revs to 6,000 and beyond, still doesn't make enough power for me.

When I'm loaded for a week on the trail, my rig weighs over 5,000 lbs. If I'm headed for hunting, add a Jeep trailer loaded to the hilt.

4.88's and 35's.

In a light trail rig or a DD with small tires, a stroker would be lovely, and have plenty of power, even for me.

For a heavy rig, towing something, or have 35" or larger tires, I'd want at least 5 liters of displacement, forced induction of some sort or a modern overhead cam, multi-valve engine.

 

[NHxj4x4]

re-did the timing, it still does the same thing. Really killing me here. Timing was just fine. One thing I did notice was some weird coloration of the plug wires (plug end) and the contacts inside of the cap. The contacts in the cap has this weird green shat on them, which I took off with a eraser, just weird that they were there. The same kinda green shat was in the end of the wires, on the plug side.

Any thoughts guys? Please......

 

[NHxj4x4]

BTT Still Stumped

 

[jeep1947]

Just a stupid question. How old is the gas in the tank? And was it from a station you normaly visit or right after the tanks were filled? My guess is that if the timing is right and its not you ignition then it is probably a stupid problem. Maby something overlooked, a plug to a sensor that did not get connected (I think we all have done that). The green stuff is most likely corosion and that is what color copper corodes to. Almost forgot with only 250 miles the engine is not even starting to break in yet, all the valve springs are still breaking in along with the cam which might cause the fluttering. I would drive it more and put in a full tank of known good premium gas along with lucas fuel system cleaner and run that tank empty and see if it goes away.

 

[rsalemi]

I didn't see anywhere that you replaced the fuel filter? Drivers side above the rear axle???

 

[CRASH]

Distributor advance working properly? Fuel pressure regulator conected to manifold vacuum?

CRASH

 

[langer1]

Distributor advance working properly? Fuel pressure regulator conected to manifold vacuum?

CRASH

Distributer advance? Where do you find that?

 

[CRASH]

Distributer advance? Where do you find that?

Controlled by the computer, sensor under the rotor, in the distributor.

I got an 87 once where the sensor was dislodged, allowing no advance. THe vehicle ran, but only to about 2500 RPM, and poorly at that.

 

[langer1]

Controlled by the computer, sensor under the rotor, in the distributor.

I got an 87 once where the sensor was dislodged, allowing no advance. THe vehicle ran, but only to about 2500 RPM, and poorly at that.

Thats the CKP Cam sensor, but is does have to be working thats for sure.

 

[CRASH]

Thats the CKP Cam sensor, but is does have to be working thats for sure.

And it controls what???

 

[langer1]

It's used to determine cylinder #one from #four at startup, after that, it's not used.

 

[CRASH]

really? Why did the old 87 start correctly every time, but would not rev? Replaced the distributor, and it ran perfect.

Seems like if it was not used after startup, it would have no effect on the acceleration ability of the motor??? Interesting.

Edit: I see how it coud affect revving after reading some SYNC stuff.

 

[tealcherokee]

id check to make sure your fuel trim is alright, mine starts sputtering around 3k rpm, and wantin to stall when i put the clutch in.....

i was running insanly lean

 

[NHxj4x4]

Thanks guys, some good suggestions. Gas is new, I had half a tank of 17mo old to start, went through that quick. Now it is Shell 94 Octane. I'll try some cleaner. I should replace the fuel filter, good call, will do that tomorrow. Disti was OK before the install, don't know why it wouldn't be now, but who knows. If the CKP only works at Start up, I should be OK there right? Fuel reg is hooked to manifold, I actually took it off, just to see, and it still stumbled. Your right as well, it's still breaking in, and maybe I'm being overly paranoid, but that's kinda how I am. I put some much into this, I just don't want anything going wrong.

So how do I check to see if I am running lean or rich? That sounds like it could be suspect. Maybe one of the mustang injectors is bunk, so how would I test that (have two spares of course)

Appreciate the help, keep it coming.

Todd