I just don't seem to have good search skills. I would like to replace the 2.8 in my "new to me" 85 GT. I want to keep it looking stock. Other than 94-95 Camaro and Firebirds, what other vehicles cam with this engine?
Grand Prix, Lumina, Cutlass Supreme, and many other GM FWD cars and possibly mini-vans. Actually, I thought any RWD engine won't work but I could be wrong.
Let’s get one thing clear from the start, as it confuses a lot of people new to this – the only engine you can use for this swap is from a 1993, 1994 or 1995 V6 Camaro or Firebird, GM part # 12363230 and also known as engine option code L32, VIN code “S”. I can assure you there are no other choices – no other car made by GM ever used this engine, so don’t bother asking about it or searching for a substitute because there isn’t one. Period. Yes, there are lots of other 3.4 liter engines made by GM, and I am familiar with each and every one of them. Yes, they can be installed in a Fiero, but they are completely different from this one, they are substantially more difficult to install, and they are not compatible with this conversion. If you would like to see what else is involved, you may wish to take a look at my other site, dohcfiero.com. Stop asking me about it, because it makes me grumpy.
Let’s get one thing clear from the start, as it confuses a lot of people new to this – the only engine you can use for this swap is from a 1993, 1994 or 1995 V6 Camaro or Firebird, GM part # 12363230 and also known as engine option code L32, VIN code “S”. I can assure you there are no other choices – no other car made by GM ever used this engine, so don’t bother asking about it or searching for a substitute because there isn’t one. Period. Yes, there are lots of other 3.4 liter engines made by GM, and I am familiar with each and every one of them. Yes, they can be installed in a Fiero, but they are completely different from this one, they are substantially more difficult to install, and they are not compatible with this conversion. If you would like to see what else is involved, you may wish to take a look at my other site, dohcfiero.com. Stop asking me about it, because it makes me grumpy.
I thought there was a difference in the blocks between a FWD and a RWD that made RWD engines not work in transaxle cars. Did that change? If so, when?
I thought there was a difference in the blocks between a FWD and a RWD that made RWD engines not work in transaxle cars. Did that change? If so, when?
The 3.4L RWD (Camaro/TransAm/S10) swap is VERY popular. It is basically drop in, except for change over of a few pieces and moving starter to other side. There is lots out there to read (Google search is best for "3.4L Fiero swap").
Yes, other engines can be fitted... DOHC 3.4L, 3400, etc... but they require more work than the 3.4L mentioned above.
OK...I will clarify the "more work" that keeps getting mentioned.
The L32 block (Camaro) is a direct replacement for the 2.8. It uses the same heads as the Fiero, which also means the Fiero intake and exhaust manifolds will bolt directly to it. You have to drill mounting holes for the starter on the other side of the block...and if you are running an auto you will need to grind down the original starter mount for clearance. Other than that, it is mostly minor tuning issues brought on by the extra flow those extra cubic inches crave. Remember, the Fiero manifolds are a bottleneck for the stock 2.8...they strangle the 3.4 even more. But...it is still an improvement over stock, especially in low end torque and reliability (better oiling).
Every other 3.4 liter block uses different heads, which translates to different manifolds. Different manifolds means that the normal things like coolant, fuel and air have to be adapted. It also means they use different sensors in different locations...and don't use a distributor...which means you are also wiring a new computer. In other words, a complete swap rather than a drop in replacement.
The 3400 (LA1) block can be used with the Fiero heads, intake and accessories making it an almost drop in replacement. The problem with this plan is that the 3400 pistons with the cast iron heads will create an excessively low compression ratio. Overcoming this problem requires replacing the pistons...which has now brought the project beyond "drop in replacement".
I didn't mean to make anyone grumpy. I can't remember asking this before? I have been watching the you pull it lots for Camero's and firebirds. Nothing seems to ever show up. I see from the above answers a S10 might also be a source? I have been watching Craig's list for complete cars with no luck. I'm not new to this stuff. My other Fiero is an 87 GT with a 427 Dart.
The grumpy text was a quote from the website, not my comment. LOL!
Did you review that site?
quote
Originally posted by woodyhere:
I didn't mean to make anyone grumpy. I can't remember asking this before? I have been watching the you pull it lots for Camero's and firebirds. Nothing seems to ever show up. I see from the above answers a S10 might also be a source? I have been watching Craig's list for complete cars with no luck. I'm not new to this stuff. My other Fiero is an 87 GT with a 427 Dart.
Thanks, Woody
[This message has been edited by jaskispyder (edited 02-03-2016).]
I didn't mean to make anyone grumpy. I can't remember asking this before? I have been watching the you pull it lots for Camero's and firebirds. Nothing seems to ever show up. I see from the above answers a S10 might also be a source? I have been watching Craig's list for complete cars with no luck. I'm not new to this stuff. My other Fiero is an 87 GT with a 427 Dart.
I am leaning towards using the 3400 block. I probable would need pistons, rings, bearings, gaskets and machine work done on either 3.4 or a 3400. It seems it would be exceptionally lucky to find an engine that old that didn't need something. I like the idea of a roller lifters. I'm pretty sure Howard's does custom cam grinding. The 2.8 in the 85 seems to be in pretty good shape. That should give me time to find cheap mini van.
I am leaning towards using the 3400 block. I probable would need pistons, rings, bearings, gaskets and machine work done on either 3.4 or a 3400. It seems it would be exceptionally lucky to find an engine that old that didn't need something. I like the idea of a roller lifters. I'm pretty sure Howard's does custom cam grinding. The 2.8 in the 85 seems to be in pretty good shape. That should give me time to find cheap mini van.
I appreciate the really good links.
Thanks, Woody
the 3400 swap is anything but easy! you will need like you said, pistons, rings, machine work (so oversize pistons and rings) main and rod bearings. gaskets. and CUSTOM PUSH RODS those can get very spendy. then set the motor up and make it all work. that custom exhaust doesnt come cheap either.
the 3.4 is well worth the wait if you wana just freshen it up and go.
for all the hassle i would do a 3800 swap and be done with it. much more potential.
I have another Fiero GT with a 427. I did the swap and thought it was pretty straight forward. I love building engines so the idea of putting together a 3400 seems like great fun. I make my own headers and exhaust so that isn't an issue. I would like to have a stock looking Fiero that performs a little better than the 2.8 does. I like the roller cam and priority oiling of the Gen III engines. I appreciate your concern and thank you got your advice.
Just remember not to mix up your push rods on a 3400. Intake and exhaust are different length. lol. But in all seriousness I wouldnt even play with the 3400, its alot more work for very little gain. I have a cammed 3.4 from a 94 camaro in my 85 GT and love it. But if I was going to have to go the effort of a new harness or computer I would just do a 3800 or LS and actually go fast.
I believe the OP is trying to maintain the Fiero "look" of the engine.
If the OP is going to rebuild the engine anyway, it's not much more work to use a 3400 block vs. a 3.4 block.
The benefits over the 3.4 block are: - an oil pan baffled correctly for a transverse engine - free cam upgrade as the roller cam is better flowing than stock Fiero cam - roller cam reduces friction which provides another increase in power - starter holes are on the correct side already
drawbacks: - you have to buy 5.85" pushrods for $140 (not a big deal if you are rebuilding with all new parts anyway) - you have to enlarge 3 bolt-holes on the timing cover (vs. drilling starter holes on the block) - you have to block a hole on the timing cover - occasionally you have to shave the oil pan or front engine mount slightly (on 88s) (vs. denting method on 3.4) - you have to buy either Camaro pistons or 3.4DOHC pistons(for higher compression ratio) ... but again - not a big deal if you are rebuilding anyway...
You don't have to get 1.6 rockers. Not doing so gives you about .410/.410 lift instead of .436/.436. The stock Fiero/Camaro cam is .390/.410 ... so it's still a slight upgrade and still reduces friction for a few extra ponies on the dyno. If you choose to go with 1.6 rockers, most of the people who have gone this route opted to go to FULL roller rockers which usually require changing the stud adapters from stock to the ones that have 10mm head side and 3/8" or 5/16" rocker side.
If I'm forgetting some minor detail, I apologize but that's really the brunt of it.
Thanks for the informational reply. I do want to look stock. I'm going to do some mild pocket and port matching on the heads and intake. I'm going to take the flat spot out of the upper intake neck and look at a larger throttle body. Nothing radical, just a nice easy to maintain combo.
Thanks for the informational reply. I do want to look stock. I'm going to do some mild pocket and port matching on the heads and intake. I'm going to take the flat spot out of the upper intake neck and look at a larger throttle body. Nothing radical, just a nice easy to maintain combo.
Thanks again.
Woody
Just so you understand, what I described are the changes necessary for using Fiero heads and intake and accessories on a 3400 block.
The build looks really well done. How did the engine run after all hard your work and engineering ?
I had my new to me 85 Fiero GT brought via flat bed to my garage. After I thawed it out ( really cold and windy today - wind chills in the -20 range) I wanted to start it. I checked the oil and none showed on the stick. I put in 2 1/2 qts. and thought at least it has some oil. I pushed the car ahead in the shop to get out of the big wet spot from the melted snow and ice. Some of the water looked a little different. I put my finger through it and it was some of my new oil. It would seem there is a ventilated oil pan! I was worried the car might run well enough that I would feel guilty putting a 3400 together. No guilt here!
Thanks for all the help and great sites to get info from. Time to start collecting parts!
It ran great for a couple of years with the Fiero ECM and distributor... ...then I decided to change to a custom intake and '7730 ecm and ruined the harness in the process...long story
I recently just built another 3.4 with 3400 block for my 88 Formula with the Camaro pistons instead of DOHC pistons and it runs great on regular unleaded. Since it was an 88, I used the stock Camaro injectors (17#) without having to do any reprogramming. 88's use Multech (so does the Camaro) where as earlier years used pintle-style injectors.
Anyway, my 88 is running great without any reprogramming and no codes. For your 85, you'll want to source pintle-style 17# injectors.
I looked at the OHC pistons and thought the sharp edges would be a detonation and flame travel issue - possibly. I decided I should go with the Camero pistons instead. I see a couple of 04 and 05 engines for sale. I am going to take a look at them and see if one might like a new home. I am afraid of computers - wire harnesses and such. I might try to learn more before I commit to the stock computer. I'm putting flow masters on my 427 Fiero today. My wife didn't like the RV mufflers it had. I made some wire looms to keep the SP wires closer to the valve covers and further away from the headers. Just little things to do on the 427 guy.
I picked up a 3400 today. It's came from a 04 impala. It has 116,000 on it. I tore it down and was surprised to find it is really good shape. The timing chain hasn't even made marks in the crank gear. No ridge on the cylinders either. I Have never seen an engine that has the pistons sticking above deck at TDC. It got a little late so I haven't measured how much yet. I'm going to order the 95 Camaro 3.4 pistons and see if the also have a positive deck height. Does anyone know if these engines have full floating wrist pins? Guess I'll find out tomorrow.
2.8 pistons are flat top 3.4 pistons have a dish 3400 pistons have a bigger dish
there is a GM 1.76" intake valve that is 4.72" long (vs. 4.75") that can be used on Fiero heads with the correct guides. I almost used them in my latest build but it wasn't a performance build so I never researched the guides. If you take the valves off the AL heads, you should measure the length/height of the intake valves. The reason for the change in guides is because those valves use narrower valve stems, hence increase flow at the valve opening. The Fiero Store SI performance valve are narrowed at the opening to also increase flow over stock Fiero valves. You could probably just machine stock valves similarly, however, switching the intake valve to a 1.76" version would increase the compression ratio slightly and allow you to machine the intake port for some extra flow.
I've also ported the exhaust ports to 1.25" incase you are also planning on making your own headers.
If you get a chance, could you measure the dept and width of the dish of the 3.4 and 3400 pistons? I once thought about shaving them down and using longer connecting rods...
[This message has been edited by lou_dias (edited 02-19-2016).]
wow, with a 1/4" dish, it would be possible to machine the pistons down and use longer rods if someone was looking to build an engine with a higher rod length to stroke ratio...
I assume those were the 3400 pistons that you measured.
Yes, I measured the 3400 pistons. If a person were to machine them flat the top ring groove would go away. The 3.4 pistons have a .085 recess. Good thing I'm just building a driver. I don't think the Fiero intake has a great deal of flow potential. It is so tempting to use all the 3400 stuff but I am trying to stay on track and not let this build get out of hand like my 427 did. I just want to have a stock look and a near 6 grand redline. I am having fun and that's what it is about.
Yes, I measured the 3400 pistons. If a person were to machine them flat the top ring groove would go away. The 3.4 pistons have a .085 recess. Good thing I'm just building a driver. I don't think the Fiero intake has a great deal of flow potential. It is so tempting to use all the 3400 stuff but I am trying to stay on track and not let this build get out of hand like my 427 did. I just want to have a stock look and a near 6 grand redline. I am having fun and that's what it is about.
Well, my 9:1 build is going thru the stock exhaust with a 57mm bored stock TB with DAWG intake neck mod and the limitation is the stock exhaust I'm pushing it all thru. Really need to go to a 2.25" system. My only exhaust mods are the shorty Sprint headerd from TFS and their crossover which is supposed to not have the D-crimp restriction. But I'm running stock cat-conv and muffler and it just feels like I can't get the air out fast enough... Hard to explain because its so different from my other build that sits behind huge 315/35-17 tires. I got a lot of crap from my dynos from AL-head fanboys but the reality is wheel weight has a direct negative affect on a dyno and I'm still making almost 170 rwhp. Even my original Mustang dyno at 187rwhp/249 on the stock roller cam was done on 255/50-16 using Camaro 16" wheels...which are heavier than stock. Wheel weight affects performance exponentionally, not linearly. So don't believe the hype. Yes, stock - AL heads outflow iron heads...but it's not rocket science to port iron heads. AL heads just came cast with larger ports where as GM never updated iron head casting beyond the 2.8 design since the extra weight of iron became uncool and head gasket and intake gasket leaks became all the rage.
I'm going to make some shorty headers and not do the crossover. I'm hoping flowmaster has a 2 pipe in 2 pipe out muffler. I was looking at valve sizes and see 3.8 motors have an intake valve .100 larger in Dia. They are only .010 longer but the catch might be the type of valve locks and the spring height. I'm in contact with a local company that regrinds cams. The cam and the no. 3 cam bearing don't look so good. I was a little surprised to find roller grooves in the cam. The main and rod bearings are still within good usable clearance. I looked at 2 other 3400 motors and both had broken cams. Hmm. I have the block stripped and I might get it off to be boiled and new cam bearings put in this week. It seems so funny to work on this tiny motor. The profiler heads on the 427 flow almost the same cfm as the throttle body on the 2.8.
I found I can reuse the 3400 stock 1.6 roller rockers by drilling out the fulcrums with a size X drill bit. They fit snuggly over the 2.8 studs and the 2.8 guide plates align them. The shorter 3400 pushrods are close to the right length. I'll have to do a mock up to check the contact pattern. The beehive springs when used with the 3400 valves retainers and valve stem seals are the correct installed height. The valves have smaller stems and the seals are the correct size to fit on the 2.8 hears without machining. All of that is a win win. The cam however, has a pitted lobe and may not be regrindable. I am going to bring the cam to a local cam grinding company and let them have a look. The roller lifter riding on that lobe is also damaged. I don't know which came first - the chicken or the egg. I'm going to see if they can grind the cam for same 112 lsa but increase the lift to .480 and the duration to 210 on the intake and 215 on the exhaust at .050. I'm pretty much guessing at those numbers.
I found I can reuse the 3400 stock 1.6 roller rockers by drilling out the fulcrums with a size X drill bit. They fit snuggly over the 2.8 studs and the 2.8 guide plates align them. The shorter 3400 pushrods are close to the right length. I'll have to do a mock up to check the contact pattern. The beehive springs when used with the 3400 valves retainers and valve stem seals are the correct installed height. The valves have smaller stems and the seals are the correct size to fit on the 2.8 hears without machining. All of that is a win win. The cam however, has a pitted lobe and may not be regrindable. I am going to bring the cam to a local cam grinding company and let them have a look. The roller lifter riding on that lobe is also damaged. I don't know which came first - the chicken or the egg. I'm going to see if they can grind the cam for same 112 lsa but increase the lift to .480 and the duration to 210 on the intake and 215 on the exhaust at .050. I'm pretty much guessing at those numbers.
Woody
Make sure you check the pushrod lengths. I thought the 3400(s) used 2 different lengths (intake vs. exhaust)... I could be wrong. I did order my .480" cam from WOT-Tech. Took almost a month for it to get delivered since they send the order to Competition Cams for manufacturing and direct ship. That cam has peak torque at 3600 rpm (like the Fiero 2.8) instead of 4000rpm of the stock 3400 cam.
The shorter push rods are 1/16 longer than the size you recommended so I know they are pretty close. I need to mock up everything to check the actual length with a push rod length checker. I am having the cam grinder go with the 112 lsa (3400 stock) and 215 duration intake and 220 exhaust duration at .050. The cam guy hasn't gotten back to me yet so I'm not sure if he can do that. My latest idea is to shave .060 off the 2.8 heads and .010 or .015 off the block. The block will be milled for "0" deck height with the 3.4 pistons. It will give me some material to remove for unshrouding the intake valve and not lose to much compression. This will also affect pushrod length as will the cam grinding.
If you end up locating a 3.4 pushrod and decide to go that route I have a bunch of build videos on my YouTube channel that will show you what needs to be done. If you feel comfortable repinning your wiring harness I'd also suggest concidering the 7730 ECM upgrade and retain your DIS. The engine runs so much better and I love the sound of the rev limiter. I have a video showing how to do it as well as another showing the sound of the rev limiter being hit.
------------------ 87 Fiero GT 3.4 Pushrod with 7730 ECM & DIS 88 MERA #8013 85 Fiero SE with 3.1 pushrod 86 Fiero SE 2.8 stock www.youtube.com/LostNotForgotton
I did buy a 2004 3400 engine. It's going into an 85GT. I'm using all the 2.8 upper engine parts. I am using the 3400 roller rockers, valves and retainers, valve seals and beehive springs in the 2.8 heads. The springs have about 40 pounds more open pressure than the 2.8 springs. The installed height is identical. I'm having the cam reground, heads milled, block "0" decked with 3.4 pistons. I want to use the stock ignition for appearance sake. This is going to be a driver. I have an 87 with a 427 that I sure can't say is a driver. Thanks you for your recommendations. The video was fun to watch!
