JimC

I installed the Hellion turbo on my car last week. Finally got the tune straightened out so it was drivable. The shop took it out for a couple of test drives with no issues. Then said "here, let's go for a ride" so I got a chance to drive it - and WOW, what a difference with the turbo.

We did one WOT getting on the highway, pulled hard. Passed a car from 55 to 70 and very quick.

On the way back to the shop heard a "ticking/clatter" like a lifter. The 3.7 doesn't use lifters it has "Direct Actuating Mechanical Buckets" where the cam lobe pushes the valve directly. We isolated it to the last intake valve on the passenger side.

Anyone have any experience fixing this? Apparently the tolerance is pretty tight and the bucket acts like a shim itself.

JimC

No one has worked on this engine I guess. The more I check on it, I'm reaching the conclusion that we broke the spring. We may have been pushing more boost than we thought. It was supposed to be set for about 6 lbs, but the boost/vacuum gauge was showing only vacuum and stopped at "0" when we got to boost.

It is not an easy repair with the heads on the engine from what I can see. You have to make sure that the tolerance for the bucket remains the same as built, pull the cam, pull the bucket for the valve and then get to the tiny retainer for the spring (and not lose the retainer in the process inside the engine) - pull the spring and replace it, get the retainer back on without losing it, and then put the bucket back in. Each bucket is set up for that particular valve and cam lobe. Pretty tedious and exacting work, and with 12 valves per cylinder lots of chances to mess up.

jz78817

I wouldn't expect boost to cause a broken valve spring. over-revving maybe.

WindyMustang

I haven't worked on this engine, but some others that have similar valvetrain have a adjustment on the DAMB that's threaded to adjust the lash. Have your shop take some pictures if you can!

It is kinda unusual to hear of a busted valve spring with boost...I'd agree it's usually an overrevving issue. Either way, busted is busted and better to fix it.

If you do wind up taking the heads off the engine, you might consider a good polish on the exhaust ports. When I changed out the headers recently I noticed that the ports are OK but not as smooth as they could be. If the heads stay on the engine I wouldn't mess with it (which is why I didn't!...).

Good luck!

JimC

Thanks. We don't think it over revved, didn't seem to be doing so on the test drive and WOT launch, never saw it go over red line. What we think happened is that the spring is compromised, sitting a little shorter than stock and not broken, but that means that the bucket is moving with no spring pressure a short distance making the sound.

Just need to find the procedure for removing the heads and cams before tackling it.

But at least the car looks good! This was at the MRT Open House today; I told Scott he might as well put it out on display since it was already there.




Need to do some painting when it gets home, get the flat black out




John offered me $100 for the 4" tips - that gets me a little closer to the repair! LOL




The cowl hood is going to be available again soon according to the company. They changed where it is built after we had so many problems with the first one, and the quality control from the original builder was inconsistent. He thinks that they have found someone else finally.



I didn't have my keys with me, and the car was locked. So shot a picture of the gauge package through the window.



And the MRT banner matches the color pretty close. John's 7 year old daughter Bailee helped to install it this morning.

JimC

"What I did today"


Picked up the Mustang and brought it home.













Dirty after sitting for almost a month




And this may be part of the problem. It was supposed to be set up for only 6 or 7 lbs of boost, but maybe it was running higher and we overboosted. The boost gauge stopped reading at "0".


And put up a video of the ticking sound. Almost sounds like an exhaust leak, but we were able to locate it at the intake valve, last one on the passenger side, with a stethoscope

Rudolph Hucker

looking good jim.
black wheels would look way better imho...those wheels dont match with anything..

JimC

Thanks, actually Rudolph the wheels match up to the vents in the hood - but a little hard to see in the pictures.

Matt's 95 Stang

Glad to see you got the problem worked out!

Matthew

JimC

I know the problem, just not sure of the fix yet! Going to be down for awhile and I'm leaning to just replace the engine and keep the other for a build. Easiest thing to do.