GM 3.6 experts... Why the disparity between different LFX engines? (Page 3/7)
dobey AUG 31, 09:11 PM

quote
Originally posted by cmechmann:
Yes the 3.6 we are seeing a lot of issues are the Arcadia, Equanox and Cadi clone. From about 08-11. The timing component issues would cause just enough "slop" in the timing chain to cause correlation codes. When you had scopes hooked up to look at the patterns, you could see the cam signals move around. You need a scope with 4 signal or 2 with 2 signal. You would dial in the patterns to get them even. Then slowly bring the rpms up and back down to see if the patterns would migrate around. You would normally see the patterns go off when the rpms came back down when the engine was under a decell condition. The timing between the front and rear cams would bounce around. Most of that was in the chain and the center guide. These were on engines, for the most part, were maintained and under 100,000. Yes we also seen phaser problems on those that had too few oil changes. The phasers would get "stuck" causing performance issues and correlation codes.
We were seeing other issues on earlier 3.6s. These also were in the crossover type vehicles. It had to do with excessive oil usage to the point it would puke oil into the vacuum chamber right after the throttle body. This would cause oil to leech down into the vacuum booster. Then it would saturate the vacuum sensor in the booster causing an ABS code. The dealers also seemed to have plenty of the boosters in stock.
The 2.8 56 degree engine in early 2000s CTS were known for burning oil.
Odd the timing belt version of the 3.0 in older Saturns, seemed to be dependable as long as they didn't have a timing belt failure or they were over heated.



Right, all those 3.6s you're talking about are the older LY7 and LLT versions, it would seem.

The 2.8 I was talking about was the Saab 2.8t (LP9 and related), which is also a High Feature engine, and the 3.0 I mentioned is as well, which was used less but primarily in the crossovers, but also in the CTS and LaCrosse very briefly. The vehicles with the HF 3.0 were all replaced with a version of the 3.6 at some point.
Raydar SEP 01, 05:57 AM
Lots of good info here. I thank everyone.
What I'm looking at doing (if I do the HF V6) is an LFX from an Impala, with an aftermarket intake, and a manual trans. Probably a Beretta Getrag (NV T-550)
Using a manual trans Camaro tune.

This thread leads me to believe it's possible.
http://www.fiero.nl/forum/Forum2/HTML/137446.html
He's doing an F23, but any quad 4 trans will adapt, sort of, it would appear.

[This message has been edited by Raydar (edited 11-22-2016).]

dobey SEP 01, 07:25 AM

quote
Originally posted by Raydar:
Lots of good info here. I thank everyone.
What I'm looking at doing (if I do the HF V6) is an LFX from an Impala, with and aftermarket intake, and a manual trans. Probably a Beretta Getrag (NV T-550)
Using a manual trans Camaro tune.

This thread leads me to believe it's possible.
http://www.fiero.nl/forum/Forum2/HTML/137446.html
He's doing an F23, but any quad 4 trans will adapt, sort of, it would appear.



If possible, I would try to find the F40 from a Saab 2.8t, for an HFV6 swap, and would fall back to adapting one of the other transmissions if that turns out to not be feasible.
Raydar SEP 01, 05:48 PM
Yeah. I know.
Except everything I've seen about the F40 is a complete pain in the ass. And would seem to require a lot more fabrication than I'm prepared (or skilled enough) to deal with. (I don't weld. Yet.) And that's aside from the initial cost of the oddball Saab F40.
If someone (Paul?) comes up with a kit that makes it a direct bolt in, then I might spring for it.

I am also quite familiar with the T-550. I have one (with the GM metric pattern) bolted to my 4.9. Since it's essentially a Getrag, it can use stock tranny mounts and axles. All I had to add was a clutch line adapter fitting (for the HTOB) and Rodney's FWD shift lever kit. Done deal. It does quite nicely, and I haven't broken anything, yet. (I try not to shock load it, but I am not averse to rolling along in gear with the clutch engaged, and then matting the right pedal.)

[This message has been edited by Raydar (edited 09-01-2016).]

pmbrunelle SEP 01, 10:03 PM

quote
Originally posted by Will:


With variable cam phasing on a DOHC--meaning that intake and exhaust phase can be adjusted independently--the "torque cam" vs. "power cam" are all handled in the tune.



Doesn't a power cam have more duration than a torque cam? In other words, something that can't be patched by a calibration?

[This message has been edited by pmbrunelle (edited 09-01-2016).]

Will SEP 01, 10:39 PM
Modern heads flow so much better than old heads that the distinction no longer applies. LS engines are making phenomenal power on cams that are fairly short duration compared to "old school" race cams... the long duration cams actually perform worse on LS's.
pmbrunelle SEP 01, 10:45 PM
I guess that also has something to do with the trend towards roller cams ... maybe less duration at 0.050" lift than previously, but more duration at high lift.
Reallybig SEP 01, 11:20 PM
Simply put, these engines are an engineering failure. I have one in a car of mine and after the timing chain fault code came up, I did a lot of research. The engine uses the oil to hydraulically actuate the phasers to modify the cams/timing. If ANY dirt is in the engine through whatever means, it will clog the 2mm passages that supply this oil and either cause the phasers to not advance or bind up the phasers and cause the insanely long timing chains to stretch. The ONLY true fix is to completely tear down the engine and flush every little bit of dirt out of these passages, which I was told is near impossible, or replace the engine. We ALL know a bit of dirt is inevitable and so is this problem. GM's fix was a stronger (I'm assuming higher carbon steel chains) and extending the warranty from 60k miles to 120 k. Many reports of this problem exist from 10k, 20 k, + even with regular oil changes. The best part is that when you hit 120k miles, GM refuses to work on your engine and i sits on replacing it for $10,000. Which you won't do cuz the book value is $8,000. This is how they force their failures off the road. Believe me, I LOVED this car of mine with this engine. Yes it is the earlier version but I also have zero faith in any of its sisters. If there is a car for sale with this engine, it's because the guy just got the timing chain replaced for the fourth time and has had enough of the piece of junk. If it's in the wrecking yard without any damage, the engine is in need of a complete teardown. Now I'm stuck driving a substandard Durango cuz it was the next option for seating 8 to my Saturn outlook. Pretty bad when a Durango beats any GM product. I was thinking about the 3800sc as an option for a swap but would be a nightmare with all the control modules talking to each other without being a GM tech insider.

Just my experience and 2am cents
Formula88 SEP 02, 09:36 AM
Imagine what a spec of dirt that can clog a 2mm hole would do to your crankshaft bearings.
Clean oil has always been crucial to engine function.
dobey SEP 02, 10:08 AM

quote
Originally posted by pmbrunelle:
Doesn't a power cam have more duration than a torque cam? In other words, something that can't be patched by a calibration?



GM's VVT technology is constantly variable, so the actual duration is controlled by the ECM as a function of the lobe duration. In traditional non-VVT setups, the torque band is adjusted higher or lower in the RPM range by duration and straight up timing. A "power cam" just moves the torque curve into the higher end of the RPM range of the engine. With VVT, the "straight up" timing is generally always best for mid-range operation, and then the ECM will advance or retard the cam using the pressure valve, to advance or retard the cam, so that the most torque and power can be made throughout the entire RPM range.