so, i wana swap out the engine on my 88 finally... i cant decide on putting 3500 LX9 into it, or a 3.4DOHC(obd1 model)... both engines have "mounts" already setup for the fiero, lets hear opinion..
so, i wana swap out the engine on my 88 finally... i cant decide on putting 3500 LX9 into it, or a 3.4DOHC(obd1 model)... both engines have "mounts" already setup for the fiero, lets hear opinion..
The 3500 is a better engine, all around. Seriously, I see no reason to use the 3.4 TDC (aside from fanboyism) when the better, newer engines are so plentiful.
The 3500 is a better engine, all around. Seriously, I see no reason to use the 3.4 TDC (aside from fanboyism) when the better, newer engines are so plentiful.
Don't think he means the LQ1 actually has issues but the LX9 is a newer engine and is simply more refined.
A member of my local club swapped one in his 87GT and this engine, although not as powerful as other common swaps, is very smooth to drive and has good all around power.
I don't know what your incentive to swap is but if you're looking for a good all around engine, the LX9 definitely has to be on top of your list.
Don't think he means the LQ1 actually has issues but the LX9 is a newer engine and is simply more refined.
A member of my local club swapped one in his 87GT and this engine, although not as powerful as other common swaps, is very smooth to drive and has good all around power.
I don't know what your incentive to swap is but if you're looking for a good all around engine, the LX9 definitely has to be on top of your list.
more power, future boost... i think ima go with the LQ1 for the 88 and leave the LX9 in my 86 rather then scrap the 86, just continue to slowly work on it / rebuild it...
Originally posted by benoitmalenfant: Don't think he means the LQ1 actually has issues but the LX9 is a newer engine and is simply more refined.
Yep.
The 3500 has cross-bolted main bearing caps, reinforced lifter valley, etc, whereas the LQ1 has basically the same bottom end as the 3.4 V6. So the 3500 bottom end is stronger.
Also, those 4 extra camshafts on the LQ1 (it has a dummy cam in the block, to turn the over head cams, so technically it has 5 camshafts) add a lot of extra weight. I don't remember the exact numbers, but it's something like 80-100 pounds more than the 3500. So even though the performance numbers are similar, the 3500 gets you a better power-to-weight ratio. And your Fiero won't be as tail-heavy.
The 3500 has cross-bolted main bearing caps, reinforced lifter valley, etc, whereas the LQ1 has basically the same bottom end as the 3.4 V6. So the 3500 bottom end is stronger.
Also, those 4 extra camshafts on the LQ1 (it has a dummy cam in the block, to turn the over head cams, so technically it has 5 camshafts) add a lot of extra weight. I don't remember the exact numbers, but it's something like 80-100 pounds more than the 3500. So even though the performance numbers are similar, the 3500 gets you a better power-to-weight ratio. And your Fiero won't be as tail-heavy.
eh? ive seen many people boost the LQ1 to ~400hp on stock internals... the LX9 needs valve work first.
eh? ive seen many people boost the LQ1 to ~400hp on stock internals... the LX9 needs valve work first.
I doubt valve work would be necessary for the LX9 to do 400, but definitely more boost. Superdave managed a little over 300 with head work and a camshaft naturally aspirated. If I were going to do an overhead cam motor, at a minimum I would start with the new gen 3.6L. The 2014 twin turbo Cadillac CTS 3.6L (LF3) makes 420 hp and 430 lb/ft of torque, that's insane from just 3.6 litres and I'm sure there will be some aftermarket voodoo available for purchase to push it to 500 hp.
Originally posted by Joseph Upson: I doubt valve work would be necessary for the LX9 to do 400, but definitely more boost. Superdave managed a little over 300 with head work and a camshaft naturally aspirated. If I were going to do an overhead cam motor, at a minimum I would start with the new gen 3.6L. The 2014 twin turbo Cadillac CTS 3.6L (LF3) makes 420 hp and 430 lb/ft of torque, that's insane from just 3.6 litres and I'm sure there will be some aftermarket voodoo available for purchase to push it to 500 hp.
I'd bet just a tune will bump it to 500, much like people are getting 300 out of the LNF on just a tune. It is a surprisingly small package for the engine, even with the turbos though, thanks to the exhaust manifold being integrated into the head, but I don't know if it would really fit up in a Fiero well.
As for the original question, the LX9 is a far better engine. If you're boosting it, getting 400 out of the stock engine can probably be done with only bolting on the turbo with enough boost, and a re-tune of the ECM.
I'd bet just a tune will bump it to 500, much like people are getting 300 out of the LNF on just a tune. It is a surprisingly small package for the engine, even with the turbos though, thanks to the exhaust manifold being integrated into the head, but I don't know if it would really fit up in a Fiero well.
As for the original question, the LX9 is a far better engine. If you're boosting it, getting 400 out of the stock engine can probably be done with only bolting on the turbo with enough boost, and a re-tune of the ECM.
hrm... while im not gona say the bottomend cant take it, i know valve springs would be a minimum requirement.
ive got the LX9 in my 86, but that car needs *alot* of work and i just dont have the time to put into it.. :/ will get to it eventually, guess i should go start it today atleast lol...
The LX9 makes the same stock power as the LQ1, but has better upgradability... You can buy parts for the LX9, but have to make almost everything for the LQ1. Also, the weight difference has been addressed. You'll lose ~25 lbs with the LX9, but gain ~70 lbs with the LQ1.
Originally posted by hookdonspeed: hrm... while im not gona say the bottomend cant take it, i know valve springs would be a minimum requirement.
ive got the LX9 in my 86, but that car needs *alot* of work and i just dont have the time to put into it.. :/ will get to it eventually, guess i should go start it today atleast lol...
I don't see why springs would be an issue. You won't be increasing the lift or the RPM range of the engine, just by bolting a turbo on. If you want to also increase lift or the RPM range, then yes, you'll probably need springs, and probably lifters.
If the LX9 is already in, then an LQ1 would be far more work to switch to at this point, don't you think?
Swapping springs is easy. Get it running and drivable, and enjoy it for a while, before you try to throw a turbo on it to get 400+ HP.
ima just do both, i *was* going to sell my 86 if i pulled the engine or sell it with the LX9 in it... now i think ima just keep it and keep building on it, and put the LQ1 in my 88...
I did an LQ1 and I like it, but I have a Cadillac CTS with the all aluminum LY7 DOHC V6 and It's quite a performer with forged crank and rods. Like the LQ1, it begs to be turbocharged. 10 PSI would be plenty of boost and both of these engines can handle it in stock form - probably much more. 10 psi on the LQ1 will provide over 400 hp and close to 450 hp on the LY7. Cadillac has a direct injection version of the LY7 that would provide even more HP.
Right, but it can be retrofitted from one of the other High Value engines that does have it. At least, from the pictures I've seen on-line, it appears to work in the same way as the VVT on the L92 and other V8s, with the special cam, cam gear, and timing cover.
Right, but it can be retrofitted from one of the other High Value engines that does have it. At least, from the pictures I've seen on-line, it appears to work in the same way as the VVT on the L92 and other V8s, with the special cam, cam gear, and timing cover.
I don't think so in the case of the LX9, IIRC, the LZ engines use different size came bearings (diameter)
Right, but it can be retrofitted from one of the other High Value engines that does have it. At least, from the pictures I've seen on-line, it appears to work in the same way as the VVT on the L92 and other V8s, with the special cam, cam gear, and timing cover.
Why would you waste the time and money?
Why not just get a 3500 that is already VVT equipped if you want it?
And why isn't the 3900 VVT being considered in all this talk of more "modern" GM 60 deg V6 pushrod engines?
3900 VVT LZ9 = 242hp / 242tq.
-ryan
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Originally posted by ericjon262: Agreed. I've been looking into a "Cam-in-Cam" conversion for the VVT 60V6, I think that would be a hot ticket. insane amount of work though...
From my experience, keep it simple and use the stock cam along with compression ratio increase on the 3900. A simple on/off mechanism to retard the cam to its appropriate optimum install angle for high rpm use will do the job.
When I installed my built version with 11.5:1 compression and a mildly upgraded reground camshaft fully advanced with the ability to retard the cam to its recommended install angle, I bested 33 mpg HWY and that was after damaging it by burning a valve. Keep in mind the motor is stroked to 4.2L another advantage of the large journal 60 degree.
I rebuilt it using a little hotter cam installed at its proper angle without the ability to advance it and with .5 less compression to 11:1 and that took me down to just over 27 mpg HWY.
If I were to do it over again, since it's turbocharged, I would use the stock cam, increase compression back to 11.5:1 and restore the ability to do a simple retard of the cam from the advanced position and take advantage of the exceptional fuel economy ability without sacrificing the performance potential.
There was also a tremendous difference in bottom end torque between the cams as well as top end although I can't do direct comparison since the first was always left in the advanced position. I would have put it up against anything off the line with the first iteration, it felt like peak torque was available at throttle tip in on launch and I'm certain the high torque level present on first install is what took out the first F40.
[This message has been edited by Joseph Upson (edited 08-27-2014).]
From my experience, keep it simple and use the stock cam along with compression ratio increase on the 3900. A simple on/off mechanism to retard the cam to its appropriate optimum install angle for high rpm use will do the job.
When I installed my built version with 11.5:1 compression and a mildly upgraded reground camshaft fully advanced with the ability to retard the cam to its recommended install angle, I bested 33 mpg HWY and that was after damaging it by burning a valve. Keep in mind the motor is stroked to 4.2L another advantage of the large journal 60 degree.
I rebuilt it using a little hotter cam installed at its proper angle without the ability to advance it and with .5 less compression to 11:1 and that took me down to just over 27 mpg HWY.
If I were to do it over again, since it's turbocharged, I would use the stock cam, increase compression back to 11.5:1 and restore the ability to do a simple retard of the cam from the advanced position and take advantage of the exceptional fuel economy ability without sacrificing the performance potential.
Originally posted by ericjon262: Are you familiar with Cam-in-Cam?
I believe it is what I saw a version of on Comp Cam's site some time ago where dual tubes keep separate the intake and exh lobes on what essentially is a single camshaft. I've taken the long way around so many times that I'm more inclined to find a way to use what's already in place when the demands of modification may require the same or more work.
And why isn't the 3900 VVT being considered in all this talk of more "modern" GM 60 deg V6 pushrod engines?
3900 VVT LZ9 = 242hp / 242tq.
-ryan
The main reason I stick with the LA1/LX9, is because the engines are a simpler install compared to the VVT engine. My next swap will either be a direct injection High feature, or a LZ9 with some custom work done.
I believe it is what I saw a version of on Comp Cam's site some time ago where dual tubes keep separate the intake and exh lobes on what essentially is a single camshaft. I've taken the long way around so many times that I'm more inclined to find a way to use what's already in place when the demands of modification may require the same or more work.
I like to explore the unknown more and more lately, I am unaware of any kind of aftermarket setup though.
Originally posted by ericjon262: I like to explore the unknown more and more lately, I am unaware of any kind of aftermarket setup though.
That used to be me, but I'm getting old now, cranky and don't like noise as much as I use to. If I find the time to build another motor it will definitely be the 3.6L.
From my experience, keep it simple and use the stock cam along with compression ratio increase on the 3900. A simple on/off mechanism to retard the cam to its appropriate optimum install angle for high rpm use will do the job.
Or keep it simple and SMART and have Sinister set up a swap PCM that retains the stock VVT...
The main reason I stick with the LA1/LX9, is because the engines are a simpler install compared to the VVT engine. My next swap will either be a direct injection High feature, or a LZ9 with some custom work done.
What beyond an extra 5-10 wires makes the VVT install difficult?
Originally posted by Will: What beyond an extra 5-10 wires makes the VVT install difficult?
well, I don't care for DBW throttles, and IIRC, the engine mounts are different. the LX9 and earlier use the same mounts as the old gen1 blocks. VVT engines are also more expensive to tune. (Not supported by DHP/tiny tuner) 5-10 wires is not a big deal to me, but to most on this forum, that's a big deal. not sure why though.
do I guess difficult was a poor choice of words, more involved would be better. the biggest part is preference. I'm also not sold on the VVT setup the LZ9 uses. I think the heads do more for the torque curve than the VVT. unfortunately, there isn't a good basline to tell how much it plays in, as there was never a stock 3900 without it.
[This message has been edited by ericjon262 (edited 08-28-2014).]
Originally posted by Will: Or keep it simple and SMART and have Sinister set up a swap PCM that retains the stock VVT...
I believe this is a DIY effort that includes the wiring and alternative engine management choice, otherwise OE engine management is a no brainer. I also believe there's a heck of a lot more than 5-10 extra wires involved unless we're talking a PCM transplant that can manage the VVT and not require the electronic throttle hardware and various other communication and handshake protocols with the BCM and TCM, etc...
[This message has been edited by Joseph Upson (edited 08-28-2014).]
I believe this is a DIY effort that includes the wiring and alternative engine management choice, otherwise OE engine management is a no brainer. I also believe there's a heck of a lot more than 5-10 extra wires involved unless we're talking a PCM transplant that can manage the VVT and not require the electronic throttle hardware and various other communication and handshake protocols with the BCM and TCM, etc...
YOUR project is a DIY PCM... I was not under the impression that OP was leaning that way.
Either swap requires rewiring. If you buy a complete engine, it comes with DBW throttle and VVT... maybe even a harness to start from. You're talking like all of this is extra stuff you have to buy... it's NOT. The only (electronic) difference worth noting is the PCM, and if a shelf tune can turn it into a stand-alone, that sounds like a winner.
well, I don't care for DBW throttles, and IIRC, the engine mounts are different. the LX9 and earlier use the same mounts as the old gen1 blocks. VVT engines are also more expensive to tune. (Not supported by DHP/tiny tuner) 5-10 wires is not a big deal to me, but to most on this forum, that's a big deal. not sure why though.
do I guess difficult was a poor choice of words, more involved would be better. the biggest part is preference. I'm also not sold on the VVT setup the LZ9 uses. I think the heads do more for the torque curve than the VVT. unfortunately, there isn't a good basline to tell how much it plays in, as there was never a stock 3900 without it.
I'd like to play with a VVT engine. They're pretty cheap. The Formula is just begging for more power, and a $600 engine that almost bolts in and gives 100 more HP is very tempting.
Are there pics around of the new style engine mounts?
I'd like to play with a VVT engine. They're pretty cheap. The Formula is just begging for more power, and a $600 engine that almost bolts in and gives 100 more HP is very tempting.
Are there pics around of the new style engine mounts?
Doesn't the 3900 also do cylinder deactivation?
some VVT engines do cylinder deactivation, some dont. I'm not 100% sure the mounts are different, I know the block side bosses are different, but that's not a big deal for a fiero swap, and I don't have a picture.
Originally posted by Will: YOUR project is a DIY PCM... I was not under the impression that OP was leaning that way.
Either swap requires rewiring. If you buy a complete engine, it comes with DBW throttle and VVT... maybe even a harness to start from. You're talking like all of this is extra stuff you have to buy... it's NOT. The only (electronic) difference worth noting is the PCM, and if a shelf tune can turn it into a stand-alone, that sounds like a winner.
Relax Will, from what I recall in an older thread on the subject by the OP, his 3500 swap consideration like probably 9 out of 10 here and elsewhere, usually forgo the OE PCM and electric throttle body since there are parts available for purchase to bypass the extra supporting hardware. I considered the OE engine management and at the time there was limited ability to reprogram, not to mention the cost of the modern programming equipment compared to what's already available and as mentioned gently earlier and more emphatically now, there's a heck of a lot more involved than 5-10 additional wires to keep the system happy, probably more like wiring two cars. Obviously we were looking at it from different platforms OBD1 vs. OBD II and even with II it's a lot of work from my research on it unless they have worked out in programming how to eliminate all the extra to keep the system happy. I've purchased several DBW engines and not one came with a harness, much less a PCM. It's all good man.
The 3900 in the Montecarlo and I believe Impala had the cylinder select option but it was phased out.
[This message has been edited by Joseph Upson (edited 08-29-2014).]
*Well Calibrated* DBW is indistinguishable from cable throttle... and also makes cruise control MUCH easier to implement (at least at the OE level) and perform MUCH better. My '92 (!) BMW 535i had EML, which was BMW's term for DBW and it made cruise control perfect. DBW also makes traction control work much better.
So if the engine & PCM have DBW from the factory, and it can be setup stand-alone pretty easily, I'd go for it. However, that's assuming that the DBW is well calibrated... Manufacturers for some reason screw the pooch on this regularly.
*Well Calibrated* DBW is indistinguishable from cable throttle... and also makes cruise control MUCH easier to implement (at least at the OE level) and perform MUCH better. My '92 (!) BMW 535i had EML, which was BMW's term for DBW and it made cruise control perfect. DBW also makes traction control work much better.
So if the engine & PCM have DBW from the factory, and it can be setup stand-alone pretty easily, I'd go for it. However, that's assuming that the DBW is well calibrated... Manufacturers for some reason screw the pooch on this regularly.
That's because their market usually isn't performance based. I can't speak for anyone else, but traction control isn't really something that interests me, every vehicle I've driven with it doesn't really have control of traction, IMO, it just acts like a big on-off switch when the wheels start spinning, making the car much harder to control IMO.
Relax Will, from what I recall in an older thread on the subject by the OP, his 3500 swap consideration like probably 9 out of 10 here and elsewhere, usually forgo the OE PCM and electric throttle body since there are parts available for purchase to bypass the extra supporting hardware. I considered the OE engine management and at the time there was limited ability to reprogram, not to mention the cost of the modern programming equipment compared to what's already available and as mentioned gently earlier and more emphatically now, there's a heck of a lot more involved than 5-10 additional wires to keep the system happy, probably more like wiring two cars. Obviously we were looking at it from different platforms OBD1 vs. OBD II and even with II it's a lot of work from my research on it unless they have worked out in programming how to eliminate all the extra to keep the system happy. I've purchased several DBW engines and not one came with a harness, much less a PCM. It's all good man.
The 3900 in the Montecarlo and I believe Impala had the cylinder select option but it was phased out.
Whether you get the harness or not depends on what you can negotiate with the yard from which you buy the engine. They want to sell you parts, so asking for a harness at least gets you a price for the harness. Anyway, with the harness and with a shelf stand-alone tune, which I understood to be available by this time, it doesn't sound much more complicated for the extra capability. Even if VVT doesn't float your boat, the extra displacement, the extra flow from the better heads and bigger bores and the extra resulting power/torque for the same size/weight package still sounds like a winner to me.
I am interested in establishing a configuration table showing which applications had which options. I thought that the Uplander/SUV version of the engine had a traditional cross-over style exhaust that would work well in a Fiero, while the cars had "cast header" type manifolds with close-coupled cats and a cross-under vice cross-over pipe. Among the exhaust, oil pan and DOD options, it sounds like there's a mix/match combo that would work very well in a Fiero.
