Breaking in a GEN-1 ~3.2 w/ H272 CAM, etc...

[82-T/A]

Hey guys,

I have a Fiero 2.8 that I installed a 3.1 crank and rods, along with a .040 overbore piston size. I did this a few years ago, and the motor actually ran quite well for a little while.

After a few months, the car really started to be down on power. It started making this noise:

Now, I know what you guys are thinking. That rattling is completely intermittent. It only happens when the engine RPMs really start to drop (like around 600-700). It'll make that noise, almost stall, and then shoot back up.

However, when I would take it out on the road, it really had no power over 4,000 rpms... where as before it actually pulled quite hard (respectively...). I just want to make it clear that it's not a main bearing, or crank bearing. The bottom end is solid. I can rev the motor and drive it around normally and there's absolutely no ratling. I've had a spun main bearing, and it's nothing like that.


So, a few years later (only uploaded the video last march though), I've undergone a complete restoration of the car. Entire front-end is rebuilt. Interior, front compartment, you name it. I'm at the point where I'm going to pull the motor, and replace my automatic with a Getrag.

Here's my question, I have a brand new H272 cam kit, along with a set of crane cam lifters. My engine only had 105k miles on it when I rebuilt it, and the machine shop said that the springs were still good. What he did was add a shim under each spring to increase the tension for the increased duration of the ARI Racing "Phase 2" cam that I was using. The shop seems to know what they're doing.

I really have no idea what's wrong with my motor, but I'm assuming I've either wiped out a cam lobe on that old cam, or perhaps there's something wrong with my distrbutor (cheap rebuilt distributor failing already?).

So I want to make everything right this time... and my biggest concern now is making sure that I don't damage the cam. When I first ran the V6 after the rebuild, I ran it for 20 minutes with increased idle (like 2,000 rpms or something). I used REGULAR motor oil, and swapped it out for synthetic after 500 miles. Probably not the best thing.

This time I plan to use break-in oil, even though the pistons and crank are already broken in.

I know I'm rambling here (sorry), but I guess what I'm asking is:

1 - Can you guys guess from my crappy video what could have been wrong with my Fiero? (note, the exhuast is not hitting anything, and I didn't have a cat on it at the time)

2 - How can I tell if there was something wrong with my cam. Do I need to replace the cam sprocket when I install my new H272 cam?

3 - What is the proper break-in procedure for the cam, what fluids do I need, and am I OK using the springs that I have... do I have to worry about flattening the cam lobes with these springs?


Just thought I should mention too that the car got progressively worse over the span of 6-7 years, but I only drove it maybe 1,000 miles during that time. I also left the same gas in there that's essentially been in there since the major hurricane we had here in South Florida (Wilma). So... I know that doesn't help. But as I said, everything is getting replaced. Every line, hose, whatever... I even bought an NOS fuel block w/ fuel regulator. I do plan to re-use my 17# Accel injectors which only have 1,000 miles on them.



Thanks guys!!!

Todd,
1987 Pontiac Fiero SE / V6

[BillS]

I'd take a good look at your valve train and cam when you get them out to see if the lobes have been worn.

Sure, you can certainly use the old springs with the new cam, but you should also use new lifters with it. Just follow the Crane break in instructions.

The 272 is about as much stick as I like to use with a middling compression engine. I run one in my 3.4 sports car with 9:1 and it works very well. Let us know how it runs with the 3.2 (I also run that engine spec in my turbo Fiero but with a customized turbo cam).

[pocket-rocket]

That sounds like when my 91 was an auto and the torque converter bolts had started backing themselves out (no locktite). You would hear mine do it when it was shut down too.

[82-T/A]

I'd take a good look at your valve train and cam when you get them out to see if the lobes have been worn.

Sure, you can certainly use the old springs with the new cam, but you should also use new lifters with it. Just follow the Crane break in instructions.

The 272 is about as much stick as I like to use with a middling compression engine. I run one in my 3.4 sports car with 9:1 and it works very well. Let us know how it runs with the 3.2 (I also run that engine spec in my turbo Fiero but with a customized turbo cam).

Thanks, I'm definitely going to do that. I know on top of everything else, I always had a constant miss. There's definitely something wrong with my timing too. I was told by the machine shop that my compression was also ~9.1 based on the piston combination and the overbore.

Eventually, I'd like to do a turbo too... but just want to get the car running well on it's own first. I have a custom chip that was made for it as well. Specific to my combination, but not done specifically to my car through dyno testing. We'll see. I'll let you know.

That sounds like when my 91 was an auto and the torque converter bolts had started backing themselves out (no locktite). You would hear mine do it when it was shut down too.

Wow... just wow... it never occured to me in a million years that that could possibly be it. But you know, it completely makes sense now that you mention it. It ALSO makes sense because I NEVER hear it when I'm moving, but when the car is idling, I would hear it. Geeze... I bet you anything you're right. Tell you what... when I pull the motor... if that's right, I'm going to paypal you $10 bucks so you can buy yourself a 6-pack of Heiniken.

I'm almost totally positive that's exactly what it is... thinking about it in my head, it makes perfect sense, and based on the fact that it would be doing it only while not under load would also make sense. Damn...


Thanks guys...

[60dgrzbelow0]

Here's my question, I have a brand new H272 cam kit, along with a set of crane cam lifters. My engine only had 105k miles on it when I rebuilt it, and the machine shop said that the springs were still good. What he did was add a shim under each spring to increase the tension for the increased duration of the ARI Racing "Phase 2" cam that I was using. The shop seems to know what they're doing. I really have no idea what's wrong with my motor, but I'm assuming I've either wiped out a cam lobe on that old cam, or perhaps there's something wrong with my distributor (cheap rebuilt distributor failing already?).

So I want to make everything right this time... and my biggest concern now is making sure that I don't damage the cam. When I first ran the V6 after the rebuild, I ran it for 20 minutes with increased idle (like 2,000 rpms or something). I used REGULAR motor oil, and swapped it out for synthetic after 500 miles. Probably not the best thing.

This time I plan to use break-in oil, even though the pistons and crank are already broken in.

Have been wrong with my Fiero?

2 - How can I tell if there was something wrong with my cam. Do I need to replace the cam sprocket when I install my new H272 cam?

3 - What is the proper break-in procedure for the cam, what fluids do I need, and am I OK using the springs that I have... do I have to worry about flattening the cam lobes with these springs?

For all Gm V-6 Engines with Hydraulic Flat Tappets, the following Camshaft Break-In Procedures are recommended:

1. Regardless of whether or not the other engine components are either broken in or well worn... FOLLOW THESE CAMSHAFT BREAK IN PROCEDURES>
2. NEVER use just Basic 30 Wgt Motor Oil...NEVER! The oil required for the time it takes to properly break in New Camshafts and other newer engine components requires the additive ZDDP.
3. Use either Valvoline Racing Motor Oil or Royal Purple Engine Break-in Oil for this purpose and follow the manufacturers recommendations for the time line for oil changes.
4. ALWAYS USE THE PROPER ENGINE OIL ADDITIVE as an addition to whatever Engine Break-In Oil you choose.
5. Before you fill and top off the lubricating fluids and coolant to the brim, make sure you fill the new oil filter with oil to the brim BEFORE you screw it into the block! (NO TRAPPED AIR)
6. From the moment you start the engine...Do NOT allow the motor to come below 2,000 RPMs for at least 25 Minutes! If you relax for even a moment...you risk wiping off camshaft lobes!
7. After that initial 25 Minute Break-In Period... shut off the engine...and REPLACE THE OIL FILTER AND OIL EXACTLY IN THE SAME MANNER/FLUIDS YOU DID THE FIRST BATCH.
8. On complete re-builds...take the vehicle out on a long stretch of road and gradually drive from engine idling RPMs up to around 45 MPH...but Don't Race The Engine...do this gradually in order to give the rings a chance to wear in slightly and get a good "tooth and groove" on the cylinder walls. Please... No Sudden High RPM try-outs here!
9. Make sure you change the oil and oil filter at 500 Miles, 1,500 Miles and at that point STOP USING THE BREAK-IN OILS or the ZDDP Additives will precipitate on the O2 Sensors and give bad readings.
10. Change the oil and filter every 3,000 miles after that.
11. Go and Sin No More...(with basic 30wgt motor oil) I recommend using Mobil1 and Mobil1 Oil Filters ...others may like a different flavor here... but keep thinking quality and you will never regret it!

Please see the attached "Picture is Worth a Thousand Words" image attached below:


Take a Photographers or Jeweler's Lupe (with a high magnification eye piece) and closely examine the Timing Set Chain and Roller Segments and well the valleys and inside and outside sprocket teeth for excessive wear or damage. If you spy anything suspicious...it would be better to replace the Timing Set along with the new camshaft at the same time and take no chances...right?

[82-T/A]

For all Gm V-6 Engines with Hydraulic Flat Tappets, the following Camshaft Break-In Procedures are recommended:

Thank you 60dgrzbelow0, this is EXCELLENT information! This is EXACTLY what I needed. I really appreciate it. It takes all the guess work out of it for me!!!

This one thread has been the most informative thread I think I've been a part of in close to 10 years.

Damn...

[pocket-rocket]

We've been around for 10 years or so, you should have joined us sooner

[2.8/3400 1985 Camaro]

I would guess that you didn't use the oil additive when breaking in the cam, personally I use that and diesel oil to break in an engine.
Now as for the tq converter....I swapped that out with my new engine....should I have locktited the bolts? And is it something that can sometimes worse and just added insurance, or is it more like a necessity and my tq converter WILL come loose if the bolts don't have locktite on them?

[pocket-rocket]

I do it for insurance and piece of mind and since I've had one come loose before. The one that came loose was a transmission change done in the back yard though. I don't remember if it was me or my friend who tightened these bolts, but either way they came loose.

[60dgrzbelow0]

I do it for insurance and piece of mind and since I've had one come loose before. The one that came loose was a transmission change done in the back yard though. I don't remember if it was me or my friend who tightened these bolts, but either way they came loose.

... and if I may add my $00.02 in here to amplify on P-R's suggestion... Having three new "Super-Bolts" like these might give you some additional "POMI" (Peace of Mind Insurance) as well.

[2.8/3400 1985 Camaro]

I can't wait till I have the money to put ARP bolts on everything,lol head studs, header studs, conrod bolts, crank to flex bolts, flywheel bolts, driveshaft yoke strap bolts, would also get them for wheel studs if I weren't planning to get titanium, now if I can just get the job I interviewed for today I'll actually be able to do this stuff in the reasonably near future...