That's the right part number crate engine you want. It is a direct bolt in. You will need to drill starter motor holes and a neutrally balanced flywheel. You can even use the 2.8 valve covers and intake to make it look just like the original engine.
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07:54 PM
LoW_KeY Member
Posts: 8081 From: Hastings, MI Registered: Oct 2001
The 3.4L H.T. is set up with a cam designed for use with a carb. Below is a quote from GM. The 82-85 trucks used 2-bbl carbs, In 86 they switched to a TBI system. You may have problems at idle with the reduced idle vacuum.
quote
The HT 3.4 is a bolt in replacement for the 2.8 V6 in your 1982 - 1985 S-10 pickup or Blazer with automatic transmission.
You could buy a Fiero cam from GM and install it. This will make the timing curve in the computer match the cam. Then just use an adjustable fuel pressure regulator to adjust the fuel requirements. I have also heard using a MAP sensor from an early 90's Camaro/Firebird with a V-8 helps the irregular idle also.
[This message has been edited by Oreif (edited 11-13-2002).]
First off, IIRC, when I checked the cam specs, the crate engine 3.4 cam is very close to and a little hotter than the 2.8L cam. Second, on the dyno, my 3.4 I feel was putting out the horsepower advertised in the Perfromance Parts Catalog. It says 160 hp and 194 ft/lb of torque. The dyno showed 136+ HP and 192 ft/lb of torque at the rear wheels. It drives good and behaves itself at idle. It's making what it's supposed to make.
OK, it's time to tell the tale.
I have a 3.4L crate engine in the Finale. New from GM. One of the biggest reasons for buying it was that it had a 12 month warranty and Chris was going to have it at school. That meant that if something happened to it, he could take it to a GM dealer, it would code just like a Pontiac Fiero, and they could work on it, under warranty. (NOTE: I knew labor was not included in the warranty, only parts)
On the way to RRR, we noticed increased oil consumption. This was after about 5,000 miles of driving with virtually no oil consumption at all.
It has seemed to stabilize at about 1 quart of oil per tank of gas. That's right, a quart every 150 miles.
We looked several places and could find no reason for it. I talked to two dealers and they both said the 2.8/3.4 had a known problem of leaking intake gaskets at the bottom that would allow oil to be drawn into the intake.
We changed the intake gaskets about 2 weeks ago and the oil consumption is unchanged, still 1 qt every 150 miles or so. There was no indication of an intake leak when we changed the gaskets.
I talked to the service manager at the local Pontiac dealership and we were to take the car in so they could open a service ticket on it, top off the oil and mark the dipstick, then seal it (somehow, I presume with wax, paint, or lead) and we were to drive it for 100 miles or so and they'd recheck the oil. Not an unreasonable procedure IMHO to determine the oil consumption.
We took the car in today and they opened the ticket. The service manager called his tech rep and he was referred to the performance parts tech rep. On talking to GM performance parts, the rep asked the service manager for the VIN, which he gave. He said "That's a Fiero?" The manager said yes. He said "Did they use the TPI off the Fiero?" The manager said yes. He said "We will not warranty that engine because anything other than carburetors on that engine voids the warranty." And then hung up on him.
According to GM's performance parts catalog, they have this to say " This is for engines with carburetors only, not released for TBI usage. This engine does not have a clutch boss on the side of the block for standard transmission application."
It does not say that it voids the warranty. GM performance parts warranty states "GM Performance Parts crate engines and short blocks carry a 12 month limited parts only warranty. Parts are warranted against defects in material and workmanship. This warranty specifically excludes engines and short blocks used in racing, any competition, or marine use, and parts that fail as a result of alteration. Should any part prove to be defective, that part and only that part may be warranted at the discretion of General Motors. The buyer assumes full responsibility for the entire cost of repair, service, damage and/or loss to property. Unless specified by GM, these engines should only be used in 1973 and earlier pre-emissions vehicles. It is the buyers responsibility to check for any state and Federal laws concerning engine replacement, modification, and emissions regulations."
We are not done with this yet and, depending on what I find when *I* tear the engine down, there may be a lawsuit pending. I could have built a 3.4L myself for half what I paid for the crate engine, but the "GM Warranty" to me, was worth the added cost. Now I find that it's worthless.
You guys suit yourselves, but I will NEVER buy another GM performance crate engine again. I can build better myself for less cost and their "warranty" is worthless.
FWIW, the service manager said that about 8 months ago he had a customer that purchased a 350 HO. The cam on that engine went flat, even though the service manager himself was there at the customers home (he's a performance kind of guy) and saw him properly break it in. That is, it was not started and immediately idled down. They attempted to warranty it initially as a driveability problem and GM never did pay the claim because the said the engine had been improperly broken in by the customer, since it was not installed at a GM dealership. The dealership was stuck with the cost of a new cam kit and the edict came down from management that there would be no more performance crate engines sold by that dealership and all performance parts from GM Performance Catalog were sold with NO warranty whatsoever. Needless to say, the experience we just had has only cemented that decision in their minds.
I can't fault the service department at James Motor Co, in Hays, KS. Byron has been a stand-up guy and has offered to help however he can. I believe I can even get at least some discount on parts, if I want to put GM parts back in this. This is all on GM Corporates shoulders IMHO.
I'm a die-hard GM fan and owner, but this is enough to turn my stomach, to deny any warranty for an oil consumption problem due to something like this is simply wrong.
John Stricker
quote
Originally posted by Oreif:
The 3.4L H.T. is set up with a cam designed for use with a carb. Below is a quote from GM. The 82-85 trucks used 2-bbl carbs, In 86 they switched to a TBI system. You may have problems at idle with the reduced idle vacuum.
You could buy a Fiero cam from GM and install it. This will make the timing curve in the computer match the cam. Then just use an adjustable fuel pressure regulator to adjust the fuel requirements. I have also heard using a MAP sensor from an early 90's Camaro/Firebird with a V-8 helps the irregular idle also.
[This message has been edited by Oreif (edited 11-13-2002).]
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09:25 PM
Kendall Bowers Member
Posts: 171 From: Greeneville, TN. USA Registered: Feb 2002
Be forewarned... GM will NOT warranty the crate engine as used in a Fiero. Having holes drilled for the starter is only one excuse they'll use if there is ever a problem. I bought a Grooms rebuilt 3.4 through Ed Parks at the Fiero Factory.
Jimminy Crickets! John Stricker, please keep us posted on what you find when you get it apart.
Ed Parks has done work for me in the past and is very trustworthy. I assume Grooms does warranty their engines without all the strings GM seems to have left dangling.
Anyone have any stories, bad or good, about Grooms, Jaspers, etc.
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09:57 PM
Oreif Member
Posts: 16460 From: Schaumburg, IL Registered: Jan 2000
Originally posted by Kendall Bowers: Orief, that's the first time I've heard about the computer timing curve/cam match with this swap. It's going into an automatic.
Any aftermarket performance enhancing, automatic friendly, computer compatible cams come to mind? Wouldn't mind a little rumble.
The cam and timing curve go together. If you change the cam, the timing curve will need to change. But since the timing curve is part of the computer program, it's not easy to do. (there are many people working on getting custom chips made and even a programmable system) It doesn't matter if it's an auto or manual trans for the cam. The 3.4L engines out of the 93-95 Camaro/Firebirds is the Economy cam. It is the next smaller size from the cam used in the Fiero. As jstricker says about the Crate engine, the cam is very CLOSE to the 2.8L hot cam, But the differences in duration and overlap are the things that are different between a carb and EFI/computer controlled system. (notice the GM spec doesn't list overlap?) The reason the idle could become irregular is the MAP sensor can't read below 13.5, At this point the ECM uses the TPS to control fuel/timing at idle. If the vacuum is borderline the computer will keep switching from MAP to TPS and the idle RPM will vary. The V-8 MAP sensor I mentioned above is rumored to have a slightly lower readable level since the V-8 is a 90* engine as opposed to a 60* engine. This should cure the idle problem.
Many who have done 3.4L swaps have been able to run the engine because the timing curve difference is close enough that the ECM can tolerate it. Although some have complained the engine runs slightly rich or slightly lean depending on which injector are used. All these things work together if you change one thing, the other parameters need to change also. Otherwise performance and economy can suffer.
[This message has been edited by Oreif (edited 11-13-2002).]
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11:00 PM
Nov 14th, 2002
jstricker Member
Posts: 12956 From: Russell, KS USA Registered: Apr 2002
BTW, if you have ideas of putting the 1.6:1 rockers on the crate engine cam, you'd best do a careful check for interference as it already has a substantial increase in lift over the stock 2.8 cam.
As Oreif noted, the overlap isn't listed.
The Crane Cam, which a few guys run is the 2030, which Crane recommends for computer controlled cars. It has an overlap of 109°. Their cam H-260-2 is almost identical except it has an overlap of 112° and is recommended for non computer cars. I called Crane when we were in the planning stages and they said the crate engine GM cam was somewhere in-between the two, with an overlap of 110° or thereabouts. Since we're pulling ours apart, I may just stick the degree wheel on and measure it to find out for sure.
What I do know is that we don't run rich on our car and the fuel pressure reads 39 pounds, just a touch low. We don't have idle problems and our idle vacuum is about 19", which is probably why we don't have idle problems.
Another factor to consider in our car is that we run the Hypertech chip which modifies the fuel and timing curves a bit. How much, I don't know. When we had it on the dyno I had intended to take my stock chip down and do a pull both ways, to see if there was a difference, but I forgot it so we didn't get it done.
John Stricker
quote
Originally posted by Oreif:
The cam and timing curve go together. If you change the cam, the timing curve will need to change. But since the timing curve is part of the computer program, it's not easy to do. (there are many people working on getting custom chips made and even a programmable system) It doesn't matter if it's an auto or manual trans for the cam. The 3.4L engines out of the 93-95 Camaro/Firebirds is the Economy cam. It is the next smaller size from the cam used in the Fiero. As jstricker says about the Crate engine, the cam is very CLOSE to the 2.8L hot cam, But the differences in duration and overlap are the things that are different between a carb and EFI/computer controlled system. (notice the GM spec doesn't list overlap?) The reason the idle could become irregular is the MAP sensor can't read below 13.5, At this point the ECM uses the TPS to control fuel/timing at idle. If the vacuum is borderline the computer will keep switching from MAP to TPS and the idle RPM will vary. The V-8 MAP sensor I mentioned above is rumored to have a slightly lower readable level since the V-8 is a 90* engine as opposed to a 60* engine. This should cure the idle problem.
Many who have done 3.4L swaps have been able to run the engine because the timing curve difference is close enough that the ECM can tolerate it. Although some have complained the engine runs slightly rich or slightly lean depending on which injector are used. All these things work together if you change one thing, the other parameters need to change also. Otherwise performance and economy can suffer.
[This message has been edited by Oreif (edited 11-13-2002).]
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01:10 AM
PFF
System Bot
Darth Fiero Member
Posts: 5922 From: Waterloo, Indiana Registered: Oct 2002
I was wondering why more of you are not using the MPI 3.1, 3100 SFI and 3400 SFI engines that come stock with aluminum heads?
------------------ 1987 Pontiac Fiero Coupe #18,838 3800 Series II SFI; 4T60-E Trans w/ 3.33 final drive; Terminator exhaust; 4 wheel vented disc conversion; Walbro 307 fuel pump; W-body air box w/ K&N filter; Rear 32mm sway bar; 134a functioning A/C; GM CD player w/ factory location sub; much more and...a stock GN's TURBO on the way!
1987 Pontiac GTA -5.7L SuperRam MPFI -4L60-E Trans -3.73 SRD
Ed Parks has done work for me in the past and is very trustworthy. I assume Grooms does warranty their engines without all the strings GM seems to have left dangling.
Grooms gives an 18 months, unlimited mileage warranty. And they know that Ed is selling them for installation in Fieros, or installing them himself. They're even okay with the starter holes being drilled. (Most other rebuilders would balk.)
FWIW, the (lack of) warranty issue that Ed told me about regarding the GM grate engine, had to do with very low compression in one cylinder. I'm not sure about oil consumption on that one, though. The problem turned out to be an out-of-round condition in one of the lifter bores. Regardless, GM refused to warranty it. "Improper application". Ed has had two Grooms engines (out of about 75-80) with the same issue, which caused oil to pump up into the heads. Grooms ultimately replaced both of those engines, and now checks all of their cores for the same problem.
Darth, The 3.4 iron head engines can use the Fiero's intake, exhaust, ignition system and ECM. The Fiero stuff wont fit on the aluminum head engines, and the intake that comes with the aluminum heads doesn't leave room for a distributor. If you retain the DIS, you have to use the ECM that came with the engine. It's been done, but it raises the complexity of the swap a few notches. If you're going to change wiring, it's almost worthwhile to go to a 3800 or a 3.4 TDC, IMHO.
------------------ Raydar
I'm not the fig plucker. I'm the fig plucker's son. But I'll pluck figs 'Til the fig plucker comes.
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07:54 AM
Oreif Member
Posts: 16460 From: Schaumburg, IL Registered: Jan 2000
Originally posted by jstricker: What I do know is that we don't run rich on our car and the fuel pressure reads 39 pounds, just a touch low. We don't have idle problems and our idle vacuum is about 19", which is probably why we don't have idle problems.
With the fuel pressure reading low, couldn't that cause the car to run lean at times? Just curious, as you stated in your first post about the oil consumption problem, the thoughts were it was a leak between intake manifold and the heads. Running lean can cause higher head temps which could cause intake gaskets to fail. It may be something to look at when you examine the engine. I'm surprised GM Parts took that position on the warranty.
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08:23 AM
jstricker Member
Posts: 12956 From: Russell, KS USA Registered: Apr 2002
That's only a few pounds low on fuel pressure, and I'm not usning the 2.8 injectors. I'm using LinTech's 3.4 injectors.
We've changed the intake gaskets once already. There was no indication that that's where the oil consumption was coming from. Maybe it will turn out to be there anyway, but I'm not pulling the intake, in the car, again. If we do the same thing we did before, the same way we did before, we'll most likely end up with the same results.
It's not running rich and it's not running lean. Why would anyone assume there was an intake leak anyway? It idles smooth at 900 rpm. It has 19" of manifold vacuum at that 900 rpm, and that's with an admittedly aggressive cam for the motor. There's nothing to indicate a vacuum leak to me and after looking at the intake ports and gaskets, once, there still wasn't anything to indicate it.
I'm surprised at GM's position as well. It's silly, in fact, if they want to sell these. I'd imagine that they really don't care if they sell them or not. Probably too low volume and not enough $$$. Whatever. They'll never sell me another one because the only thing that made them worth a portion of the cost was the warranty, and there is none. As others have pointed out, Jasper and Grooms do warrant their engines. Also, if I build it myself, for half the price, every other one of them can have a catastrophic failure that ruins every part in the engine and I still come out even with GM pricing.
John Stricker
quote
Originally posted by Oreif:
With the fuel pressure reading low, couldn't that cause the car to run lean at times? Just curious, as you stated in your first post about the oil consumption problem, the thoughts were it was a leak between intake manifold and the heads. Running lean can cause higher head temps which could cause intake gaskets to fail. It may be something to look at when you examine the engine. I'm surprised GM Parts took that position on the warranty.
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08:44 AM
jstricker Member
Posts: 12956 From: Russell, KS USA Registered: Apr 2002
In my case, I wanted to use the stock ECM so the engine would code properly, using the stock intake. YOu can't do that with the aluminum head version, intake won't fit. I already explained that it was a daily driver that we built to be able to be serviced by any GM dealership just like any other Fiero.
Now that it's done, with all GM parts, I find that I have no warranty and one dealership has refused to work on it. So much for GM's service and warranty.
John Stricker
quote
Originally posted by Darth Fiero:
I was wondering why more of you are not using the MPI 3.1, 3100 SFI and 3400 SFI engines that come stock with aluminum heads?
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08:51 AM
Nov 15th, 2002
FasterPleeze Member
Posts: 19 From: Lexington, SC USA Registered: Oct 2002
This whole swap sounds way too good to be true to me, except one thing...the power and torque figures (stock and modded). Does anyone have any info on those? Thanks!!
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01:08 AM
FasterPleeze Member
Posts: 19 From: Lexington, SC USA Registered: Oct 2002
Depends on which 3.4L you use. If you look a few posts up, I gave the advertised hp/torque figures for the crate engine and the actual rear wheel dyno numbers.
The weight difference is almost nothing. If anything the 3.4L might be a tiny bit lighter simply because more iron is gone from the block and replaced with aluminum. But I bet the difference is less than 5 pounds, one way or the other.
John Stricker
quote
Originally posted by FasterPleeze:
This whole swap sounds way too good to be true to me, except one thing...the power and torque figures (stock and modded). Does anyone have any info on those? Thanks!!
[This message has been edited by jstricker (edited 11-15-2002).]
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03:13 AM
Oreif Member
Posts: 16460 From: Schaumburg, IL Registered: Jan 2000
This whole swap sounds way too good to be true to me, except one thing...the power and torque figures (stock and modded). Does anyone have any info on those? Thanks!!
Stock 3.4L is 160hp/194 torque Modded is a loaded question. How modded? Basically with many mods, the Fiero intake will support about 190-195hp. With other than Fiero intake, you can get over 200. Many here who just do some minor changes see about 160-170hp. Then of course you can add forced induction (turbo or SC) and get over 200hp too.
