I have a 3.4 crate motor for my 87 Fiero, still sitting in a crate while I finish up my daughter's Fiero. But I happened to be looking at ARI Racing's website and discovered that they have a few cyl heads that they've both ported and polished, AND have new SI stainless steel valves on them. I don't know what kind of horsepower I can expect from that (though would be interested if you guys have an idea what a stock for stock engine would be with the swirl-stainless valves and a mild port / blending). In any case... I'm going to have a completely assembled 3.4 that I'll be pulling the heads off of, and then replacing them with another set of completely rebuilt heads. So I have a few questions if you guys don't mind very much giving me your thoughts:
1 - Cyl Head Bolts - I'm assuming I cannot re-use these cyl head bolts, correct? Even though they were used once, and the engine never even started. I should replace the bolts because they stretch, right? I've reused cyl head bolts in the past on Duke engines, but I assume I wasn't SUPPOSED to do that. It seemed to work just fine for the life of the car, even after I sold them (did this with two cars).
2 - ARP Bolts - Is there any reason why I should use standard cyl head bolts? Would I be better off using ARP studs and nuts? For what it's worth, I've had a bad habit of breaking threads in a block... mostly because I had a shitty torque wrench that I think was broken and never clicked, so I just kept going at it. Are ARP studs a better option, and off the top of your head... does this affect any brackets that attach to the engine? (I can't remember)
3 - If YES on #2, is the torque sequence (and torque specifications) still the same with ARP studs as they are on the normal Cyl head bolts?
4 - Even though the engine has never been run, I assume that I need to buy a new head gasket, correct? Other than the standard quality Felpro... is there a better / higher quality head gasket I should be using, perhaps one that might improve compression? Stock will be 9:1 on the 3.4 (as opposed to 8.9:1).
For what it's worth, the new heads will already be planed / decked for straightness, magnafluxed, etc... Thanks!!!
if you know the torque wrench is broken buy a new one.much cheaper than that other stuff.i have one from harbor freight that seems to work right.
Yeah, I stopped using it after I snapped a head bolt on two engines in a row. That was like almost 20 years ago though... and from that point on I went with a needle-gauge torque wrench. But for the greater part of a decade, I just didn't work on cars at all. So that torque wrench I THINK is long gone (don't even know where it is), and I do plan to buy a new one anyway. So that isn't an issue.
1 - Cyl Head Bolts: GM V6 engine head bolts are Torque-to-Yield design which means they should NOT be reused! Also, it is important to use new washers with each individual bolt when reinstalling them in order to ensure proper seating and clamping force on the cylinder head surface area.
2 - ARP Bolts: To me, you can use standard NEW head bolts, not 'used'!
3 - The same torque specs; check but I found this spec on-line:
"The torque-to-yield head bolt specs for a GM 3.4 liter engine are as follows: Stage 1 – 44 ft.lbs., Stage 2 – 88 ft.lbs., and Final Torque – 103 ft.lbs plus an additional 90 degrees of rotation to achieve the final torque spec."
4 - To me, new head gasket......
Edit: Buy a 'Brand Quality' torque wrench as to me, 'Harbor Freight' brands aren't the best........
------------------ Original Owner of a '88 GT and under 'Production Refurbishment'
[This message has been edited by Vintage-Nut (edited 09-13-2023).]
If you are willing to drop coin on a set of ARI heads, adjust (increase) your budget to include $400 for a Snap On torque wrench. Any torque wrench from Snap On will be able to be calibrated in the future, and will come with a certificate of calibration. Properly torquing a head on any engine is not something you should cut corners on.
1 - Cyl Head Bolts: GM V6 engine head bolts are Torque-to-Yield design which means they should NOT be reused! Also, it is important to use new washers with each individual bolt when reinstalling them in order to ensure proper seating and clamping force on the cylinder head surface area.
2 - ARP Bolts: To me, you can use standard NEW head bolts, not 'used'!
3 - The same torque specs; check but I found this spec on-line:
"The torque-to-yield head bolt specs for a GM 3.4 liter engine are as follows: Stage 1 – 44 ft.lbs., Stage 2 – 88 ft.lbs., and Final Torque – 103 ft.lbs plus an additional 90 degrees of rotation to achieve the final torque spec."
4 - To me, new head gasket......
Edit: Buy a 'Brand Quality' torque wrench as to me, 'Harbor Freight' brands aren't the best........
Thanks, great advice, I appreciate it. I'll definitely go with new bolts then. I have to pick up a higher output oil pump too (per Sleek's advice), so I might as well order all that from ARI while I'm at it along with some other things.
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Originally posted by lateFormula:Here's my advice:
If you are willing to drop coin on a set of ARI heads, adjust (increase) your budget to include $400 for a Snap On torque wrench. Any torque wrench from Snap On will be able to be calibrated in the future, and will come with a certificate of calibration. Properly torquing a head on any engine is not something you should cut corners on.
Haha, I've never heard it referred to that... but yeah, I saw they had the SI valves, and an already (professionally) ported heads... and I was like... what the hell. These won't last. Eventually someone is going to buy them and then that's it. I already missed out on a set of original GM aluminum Gen-1 heads because I didn't have the $500 bucks like 10+ years ago to buy them... so not letting these slip away too.
quote
Originally posted by buddycraigg:
Is this ARI in Grandview MO? I worked in the head department 25-30 years ago for about a year.
Yeah, apparently the owner's dad passed away a couple of years ago unfortunately. But his son is carrying the torch now. They've always been pretty awesome with the Fiero community.
Just watched the video! The "Vintage Craftsman" that he had, is literally the exact same one that I had...
I'm surprised that the ICON from Harbor Freight did so much better than the vast majority of the others. Personally, the one I liked the most was the DeWalt... which, even though it's made in Taiwan, it has a nice grip and a much longer handle, which will make it easier for my daughter to use.
As for horsepower from the 3.4L P/R engine, stock is 160HP with a bit more torque. With a ported head you may get to 175HP . The improvement will be noticeable but not dramatic
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
As for horsepower from the 3.4L P/R engine, stock is 160HP with a bit more torque. With a ported head you may get to 175HP . The improvement will be noticeable but not dramatic
Thanks Dennis, that's a reasonable number... and I'll be happy with it. It's still 35 more horsepower than it had when it was stock.
Yeah, I remember this video. So in your other set of heads, you actually installed larger valves? I know you have a totally different intake, but did you notice a significant increase from the larger valves?
Truth be told, I just wanted the valves, but couldn't find them anywhere. I eventually discovered that ARI had a set, but only already installed in the heads. So I was like, ok, I guess I'm getting heads.
The performance heads were a "mild port." So definitely not like what you have... but I just didn't want to put in a 3.4 V6/60 without at least trying to do a little bit.
Speaking of... when I had the heads off, I noticed it said 1.00 on the cyl head. Does that just mean standard size? Or is that a massive overbore? There was no spec sheet or documentation really with HOW the rebuild was done.
I was expecting to see something like .010 or .020 on the piston tops... but a big honking 1.00 ... no idea what that's suggesting.
EDIT: I just found this...
"Conversion factors my man! There are 25.4mm in one inch so each .001" equals .0254mm. 40 x .0254 =. 1.016mm. SOOOOOOO! .040" = 1.0mm"
Ok, so they are .040 overbore pistons. Man... someone must have really ragged out that engine to need .040 overbore pistons, or it had a **** -ton of miles on it before they rebuilt it. I had to go w/ .040 pistons on my daughter's Iron Duke, but that had almost 200k miles on it.
[This message has been edited by 82-T/A [At Work] (edited 05-26-2024).]
