Exhaust running hot

[bfarroo]

The exhaust manifold and turbo on my hybrid daytona have always run hot. I'm hoping to take the car to SDAC this year and want to get things running right. I've double and tripple checked cam timing and played around with the adjustable gears but haven't been able to get it running quite right. I've noticed slight backfiring into the intake when cold which makes me think it's a cam timing issue but retarding the intake cam didn't make a large difference. I pushed it back one tooth and reset the gear at 0 and it didn't have the backfire anymore but the engine didn't have much power and didn't want to boost much. with the original setting it had good power. I pulled the head to look everything over and don't see any major issues. I don't see anything that would indicate the valve not sealing. although it's hard with the valves in the head. I was thinking of pulling the valves and lapping them if that's something people still do or else I have another head here that I am planning on rebuilding to put on this motor but probably won't have time before SDAC. Any suggestions? is there a special tool for removing the valves on these motors? LMK.

[glhs0426]

This works if you have the cams out. Install the spark plugs. Lay the head upside down. Fill the chambers with parts washer solvent/mineral spirits. If the fluid runs out any ports, you have leakings valves. Not scientific, but a quick check that works.

[bfarroo]

Sounds like a good start, takes 5 minutes to pull the cams and give it a check. If the valves are leaking whats the best fix short of a valve job.

[turbovanman²]

Sounds like a good start, takes 5 minutes to pull the cams and give it a check. If the valves are leaking whats the best fix short of a valve job.

The HEAD has to be off the car, :eyebrows:

Don't Neon cams have a flat spot or something to lock them in place. I would do that, then set leave the cam gears loose and put the belt back on, that way you know 100%, the cams are straight up.

Oh, how do you know the exhaust is running hot?

[bfarroo]

Cruising down the highway and stopping and popping the hood shows the turbo/exhaust manifold with a glow. This is not boosting or running it hard just cruising at 60mph. The head is off and on the bench right now so checking for leaks is easy now. for setting the timing there are dowel holes in the cams that you set straight up and that is suppose to be the TDC setting for the cam.

[turbovanman²]

Nasty, yeah.

Sure you have the right cams or combination of cams?

[bfarroo]

As far as I know they are the correct cams for the head. the entire head is from a Neon. I'll have to look and see if there is a PN on the cams and check if they are right. I know a NA cam is going to have more overlap than a turbo cam but haven't heard anyone else with this issue.

[BadAssPerformance]

Could be ignition timing too maybe? Or too much fuel anmd afterburing?

[glhs0426]

The 2.0 Avenger cams will not run with stock neon or 2.4L electronics. Well, they run but not good enough to drive the car or make much vacuum. Neon guys have run all other combinations of 2.0/2.4 stock cams with no adverse effects. I forget, what electronics you are running?

[turbovanman²]

The 2.0 Avenger cams will not run with stock neon or 2.4L electronics. Well, they run but not good enough to drive the car or make much vacuum. Neon guys have run all other combinations of 2.0/2.4 stock cams with no adverse effects. I forget, what electronics you are running?

That's good info, I don't remember anyone mentioning that before.

[bfarroo]

Running the stock SBEC. I'm going to check over the valves. I need to get a spring compressor. I am getting a slight leak through a few of the valves when I fill the chamber with the head upside down and cams out. I'll try and find some lapping compound and clean them up and put it back together. I have the stuff here to burn chips so I'll have to find a 16 valve SBEC cal to start with and get a better tune in there also. I'll double check the Fuel Pressure when I get it back together and I'm going to order a wide band. SDAC is getting close and I've been working 65 hrs a week, worked 90 hours last week so I haven't had very much time for the cars.

[bfarroo]

What kind of valve spring compressor should I get to remove the springs on the neon head. Doesn't look like there is much room in there.

[shadow88]

A large c-clamp type of compressor works great on those heads. Some are better than others and most of them require a little grinding of the part of the tool that actually touches the valve retainer.

I like JT's thoughts of incorrect ignition timing. I had my manifold and turbo emit light when I was running very retarded timing.

While the valves are out, be sure to check the guides for wear.

[bfarroo]

Got the valves out and cleaned up the head. Lapped all of the valves and put them back in. One thing I'm seeing is the valves don't completely close now. The lifters are not bleeding down after I put the head back together. Will they bleed down on their own or should I compress them manually. I pulled the lifter out for one cylinder and compressed them and put them back in and everything is good on that cylinder.

[bfarroo]

After sitting overnight the lifters went down by themselves so the problem solved itself.

[turbovanman²]

Is it running?

[bfarroo]

Got the head on and exhaust manifold bolted up today and the turbo reclocked. Installed a new starter power wire as the old one looked bad. Hopefully I can finish the new downpipe tomorrow and I have to weld something to the compressor cover to bolt the WG can to. After that it's just the intake plumbing. Hopefully by the weekend it'll be running.

[bfarroo]

Got the car back together and running. Only have a few miles on it but it seems to be running good, idle is better. I still have a slight stumble on tip in but other than that all's good. The exhaust manifold is about 850 degrees after a 10 minute cruise down the highway.

[turbovanman²]

Excellent, :nod:

[glhs0426]

So, lapping the valves was the only change?

[bfarroo]

Yeah pretty much, I opened up the bump in the bottom of the exhaust ports a little but other than that nothing else. The valves were a little rough. I have another head here that I'm going to go through and spend a lot more time porting and get put on the engine when I have more time.

[bfarroo]

Here's the new manifold, The pulse manifold I had on there did make the spool up noticebly faster so I may try to build another one but get the turbo down farther.

http://www.extremepsi.org/gallery/albums/album07/DSC01934.jpg