My V8 Fiero with a worn out engine has sat untouched and neglected for 11 years. As a combination retirement and pandemic project, I have restarted my SBC Fiero swap. I have forgotten half of what I once knew. So, I will have questions for those that have done this swap before.
Teaser photo taken yesterday (see image). Just another old school 400 HP SBC 355. I can provide specs if anyone is interested.
First question is about water pumps, I bought a Meziere electric pump because I have one in my 2004 GTO that has held up well. Now that it's trial mounted on the engine (upsidedown), it looks big. Will this pump work? Has anyone else used one before?
The old school SBC approach looks nice but is seldom used anymore for three reasons. 1. The tight fit in the engine compartment due to overall length. Using that water pump will necessitate cutting away a portion of the wheelhouse. To avoid this you can use a remote electrically operated water pump. 2 You cannot use a later day (stronger) GM automatic transmission. You can use the TH125 but it must be custom built to take the power and it limits you to three speeds. 3. If you go manual the Getrag is a poor choice as it will only survive long term with 200 ft lbs of torque. If you use an engine with twice the power you will need to change to the stronger F23 or F40. Not trying to discourage you, just advise what needs to be done for a reliable swap.
------------------ " 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 "
I have a CSR brand pump on mine, it looks almost the same, its a tight fit vertically, depending on how low your engine is set into the vehicle. Length wise yo need to have a hole on the inner wheelhouse, maybe you can beat it down with a BFG for clearance? or mount remotely as previously stated.
------------------ 84SE, aero body, 4 speed and an injected 355 V8
Dennis, you provided valid points and excellent advice. However, my Fiero already had a SBC swapped in 22 years ago when I bought it. Then, in 2010, I started building this engine (photo in post 1). The short block is done and I had already gathered most of the parts (about $4k spent on the engine). Long story short, I'm stubborn and committed to staying old school.
Previously, I had a belt driven water pump with the cogged pulley in the wheel well, but this time I wanted to go electric. So, there has been some cutting and trimming done. You mentioned remote locating an electric pump. I had not seriously considered that option yet. But, I think it might be a worthy "Plan B" if the Meziere doesn't fit while mounted on the engine.
2 You cannot use a later day (stronger) GM automatic transmission. You can use the TH125 but it must be custom built to take the power and it limits you to three speeds.
Countless people have swapped in a 4 speed automatic TH440 into a stock Fiero V6 or 4 cyl. If those are interchangeable with the L4 and V6, why wouldn't it be interchangeable with the V8 if the TH125 works with the V8?
I'd rather not have a big debate over transmissions. Yes, you can swap in a 4 speed OD auto like what the Grand Prix GTP used. Seems like you have to change axle length, etc.
The little TH125 in this car held up like a champ for many years, so I'm going to freshen it up and keep using it. They are tougher than most people think. Some folks have different opinions.
Back to the water pump, after some measuring and eyeballing, I think the Meziere unit I have will fit, if I do a little more wheel well trimming. If not, I'll mount it remotely and get a pair of block adapters.
Next problem, the dogbone bracket on the engine appears to be homemade and might not fit onto the intake manifold I have on the new motor. Also, looks like rodents have chewed up some wires.
I ran my Getrag for around 26K miles with a ZZ4 and no issues whatsoever.
I built mine in 1999 and drove it until 2007 when the ZZ4 cracked the block. Then it sat until 2015. This year I finally finished it with a fresh 355 from a seasoned block. Yep, my first version had the Gilmer belt driven water pump, just like yours. Now it's a Meziere pump.
We're in the same boat and I'll be glad to help you out with any questions.
------------------ 88GT 355 CI Sequential Holley HP Multiport EFI, AFR milled 180, Dyno'd at 427 HP, 360 WHP, F40 6-Spd anderson@gdsconsulting.com
Thanks Steve, if I get into a bind, I might just PM you. I feel better knowing you got a Meziere to fit.
MafV8 used a CRS electric pump. I looked up some photos and that pump looks a lot like the Meziere.
I'm in the process of disconnecting the old engine and getting ready to drop it out. I'm taking photos, using painter's tape to label stuff and putting small parts in ziplock baggies.
But, the good news is the dogbone mount will work fine on the new engine, so I'm sanding off the rust and will paint it. I have poly bushings ordered for the dogbone.
So, progress is being made even if it's moving at a snail's pace. But, the throttle linkage is cobbled together. I might need to figure out something better.
Originally posted by Dennis LaGrua: 2 You cannot use a later day (stronger) GM automatic transmission. You can use the TH125 but it must be custom built to take the power and it limits you to three speeds.
quote
Originally posted by reinhart: Countless people have swapped in a 4 speed automatic TH440 into a stock Fiero V6 or 4 cyl. If those are interchangeable with the L4 and V6, why wouldn't it be interchangeable with the V8 if the TH125 works with the V8?
Dennis simply doesn't know what he is talking about
The SBC has been paired with just about every FWD automatic transmission. 125C, 440T4, 4T60, 4T60E, 4T65e-hd, 4T80, TH325, & TH425 - most are documented with build threads on PFF. There is nothing specific about the SBC that doesn't allow the use of any of these transmissions. Like every swap, there are specific details to work through, but every one of these transmissions has been used with a SBC in a Fiero.
Batboy, It's too late now but I went through two sets of those block hugger headers and they always leaked either from leaks at the collector or along the flange or both. I learned of the Tru Ram from an old Guru thread. That's what I have now.
I know what it's like to lie on my back and replace that forward header.
They fit and don't leak.
My first build in 1999 never used the dog bone. Instead there was an adjustable rod end link that went from the cradle to the rear of the aft cylinder head. I have a photo of it if you want.
Steve, the headers I have are Sanderson C90. Is that the same headers you had trouble with? Those flanges are sometimes tough to seal up. I've used the block huggers and ram horn manifolds on my street rod. Real copper gaskets and a little bit of copper RTV seems to work for me.
I have seen photos of the adjustable bar. Were there any pros or cons compared to the upper dogbone?
Ok, my next stumbling block is the throttle linkage. The bracket on my old engine will not fit onto the new engine. Suggestions? Guess I'll be searching the forum tonight for ideas.
[EDIT] After reading several archived threads on the subject, I have Edelbrock 8030 throttle bracket in my shopping cart. Is there anything better?
[This message has been edited by batboy (edited 09-13-2021).]
Those Sanderson block huggers are the same ones I had.
Since I never used the dog bone I have no comments to offer. In this 2nd generation of the car I added an F40 6 speed and all mounts are solid.
As far as the carb mount, I have no experience with that linkage yet. My first build was a TPI, followed by BigStuff 3 multiport injection. The current build of 2015 began with Holley HP multiport and I'm in the process of converting to a 4 BBL for the 1st time.
As a side note, I'm selling the entire Holley SBC EFI system complete with matched 36# injectors, Pressure regulator, 1000 CFM billet 4BBL and a 3.5" touchpad. The entire system has less than 2500 miles on it.
This morning, I ordered the 8030 throttle bracket made by Edelbrock. Now that you gave me the head's up about those headers sealing poorly, I will take extra care.
This car has like 4 coolant sending units. The trouble is I only have 3 places on the new engine for coolant senders. According to the nice diagrams and info on the Fiero Store website:
Coolant Fan Switch - This switch screws into the intake manifold vertically, next to the thermostat housing and the cold start injector switch. It has a one wire connector. Temperature Gauge Sending Unit - This sending unit screws into the corner of cylinder head, near the ignition coil and the valve cover. Coolant Temperature Sensor (for the ECM) - Located below the thermostat housing. This sensor screws into the intake manifold horizontally and has a two wire connector. Cold Start Injector Switch - Located next to the thermostat housing. This switch screws into the intake manifold vertically, next to the thermostat housing and the fan switch.
Nothing on the sbc carbed engine I'm installing is computer controlled. So, I should be able to eliminate the last two senders. Correct me if I'm wrong, but all I really need is a two wire sender for the water temp gauge (and idiot light) and the one wire radiator fan switch, right?
[This message has been edited by batboy (edited 09-14-2021).]
Update: Had to catch up on yard work and I also helped a friend work on his car. I'm back on the Fiero now. Just taking my time and disconnecting wiring, trans cable, throttle cable, etc. Now I'm pulling off coolant hoses and will need to remove the water pump from the old engine. I hope to have the cradle dropped this weekend.
Question: How do you route the heater hoses when you have an electric water pump with no heater hose fitting? I don't want to route the return heater hose to the radiator (besides there are no hose barbs there anyway). The heater core feed hose will come from a fitting on the intake manifold like normal. About the only thing I can think of is to get a thermostat housing with a hole pre-tapped for a fitting. That should work, right?
I went through the exact same thing when I converted from my old belt driven pump to the electric. It's not rocket science but too much to write here. If you PM me your email, I'll walk you through it.
Right now my car is not running and not up on jack stands or ramps. I need a few days in order to take another look and shoot photos of the plumbing.
I got everything unhooked that I can reach from the topside. Tomorrow I'll set up the jack stands and work on the greasy side.
I dug around in my parts bins and found a SBC thermostat housing with 2 bungs. The heater core will be fed from the hose on the intake same as most SBC. The heater core return hose will connect to a fitting on the stat housing. The heater core hoses will also acts as a bypass loop when the thermostat is closed.
I noticed the radiator overflow container is cracked in several places. Is there a source for the overflow tank?
I hooked up my heater hose, to a fitting in the leg of the water pump assembly that attaches to the block. The other hose attaches to the intake manifold as normal.
------------------ 84SE, aero body, 4 speed and an injected 355 V8
Originally posted by batboy: ... I noticed the radiator overflow container is cracked in several places. Is there a source for the overflow tank?
If you have enough room under the decklid, install a hose fill fitting, with an overflow, near the engine. Buy a parts store (or other) overflow bottle and mount it there. Remove the overflow from the front, completely. Install a 20 lb. cap on the radiator. Install a regular 15-16 lb cap at the rear.
I did this with my 4.9, and have never regretted it.
[This message has been edited by Raydar (edited 09-17-2021).]
Hey Raydar, I see you still hang out here. That 4.9 looks like it belongs there. I had to do a remote radiator fill like that on my street rod.
I found out the Fiero store has the coolant overflow tanks. I got all the fittings I needed from the local farm and ranch store today. So I now have the heater hose plumbed. I had broke the tube that the oil pressure sending unit sits on, but it's replaced now and reinstalled. The throttle bracket was delivered today, so I got that put on. I spend more time tweaking the dogbone bracket and finally got it the way I want. Lots of little things done today. I'm ready to work under the car starting tomorrow.
Here's what the engine compartment looks like right now. Yuck! That's what happens when a Fiero sits outside for 11 years. Once the cradle is dropped, I'll need to spend a couple of days cleaning and painting.
No questions today. Maybe I'm finally getting a handle on this thing. Thanks to everyone that has helped me.
I got everything unhooked that I can reach from the topside. Tomorrow I'll set up the jack stands and work on the greasy side.
I dug around in my parts bins and found a SBC thermostat housing with 2 bungs. The heater core will be fed from the hose on the intake same as most SBC. The heater core return hose will connect to a fitting on the stat housing. The heater core hoses will also acts as a bypass loop when the thermostat is closed.
I noticed the radiator overflow container is cracked in several places. Is there a source for the overflow tank?
Sorry, it's late & I'll catchup with this thread tomorrow.
You should be good with that electric pump I've used a lot of them.
However, The main reason I'm posting tonight is that the 5/8" heater hose from the intake manifold is water going to the heater core. The 3/4" heater hose coming from the heater core has to feed into the large fitting on the water pump. If you have the 3/4" hose attached to the gooseneck it will be trying to go against the upward flow that's the natural flow thru a SBC.
Put a "T" fitting into the right side waterpipe or weld up & put in a "T" fitting into the Large hose going into the water pump.
Since this is an older install, I'm going to try to remember to update you tomorrow on part numbers for the hoses you can use.
Hope that helps
Archie
[This message has been edited by Archie (edited 09-18-2021).]
Originally posted by batboy: Back to the water pump, after some measuring and eyeballing, I think the Meziere unit I have will fit, if I do a little more wheel well trimming. If not, I'll mount it remotely and get a pair of block adapters.
Dedenbear water header cleans up the plumbing a good bit compared to separate adapters.
Question: How do you route the heater hoses when you have an electric water pump with no heater hose fitting? I don't want to route the return heater hose to the radiator (besides there are no hose barbs there anyway). The heater core feed hose will come from a fitting on the intake manifold like normal. About the only thing I can think of is to get a thermostat housing with a hole pre-tapped for a fitting. That should work, right?
I know you said you already solved this, but... What year is your car? Starting in '87 the heater core return T'd into the right side coolant pipe. That would be perfect for your application. I swapped my '87 to the earlier style heater pipes because they work better with the way the Northstar heater circuit has to be plumbed. I can send you my '87 heater pipes and right side coolant tube.
quote
Originally posted by batboy:
I noticed the radiator overflow container is cracked in several places. Is there a source for the overflow tank?
The Fiero Store has repro overflow tanks. (oh yeah, you found that too)
[This message has been edited by Will (edited 09-18-2021).]
If you have enough room under the decklid, install a hose fill fitting, with an overflow, near the engine. Buy a parts store (or other) overflow bottle and mount it there. Remove the overflow from the front, completely. Install a 20 lb. cap on the radiator. Install a regular 15-16 lb cap at the rear.
I have something similar for my Northstar... The engine itself has no fill point. I used a Moroso inline filler neck at the back and CAPPED OFF the overflow port. I retained the stock plumbing at the front. With a lower pressure cap at the back, it burps air out at the rear fill, then when shut down and cooling, pulls water in from the overflow bottle at the front... it purges both ends with one bottle.
Archie says plumbing the 3/4" heater return hose to the thermostat housing is not ideal. Ok, then I will T into the water pump hose instead.
I dug around in my recycled parts box and found a Moroso in-line fill cap like Raydar is using (since I have it, might as well use it).
I have two radiator hoses ordered from O'Reilly Auto Parts: Gates 20983 and 20538 (Steve provided me with those part numbers).
Will, this is a 1985 Fiero . I can't seem to find a photo of a 1987 coolant tube with a heater hose T. But, it sounds like that might be the ticket. I'll pm you later this evening after I'm done working for the day.
I'm not seeing how that Dedenbear part will (can) work any better.
This is an old picture but you can see the 2 water fitting areas on the front of the SBC block. The right leg of the Dedenbear part is pointed in the correct direction but the Left leg would clearly point toward & interfere with the frame rail & the suspension parts. That end of the Dedenear would only work if it was deadheaded & that would force all the coolant thru the right leg. Far from cleaning up the plumbing, Hoses & fittings to make the Dedenbear work would "dirty up" the plumbing.
UPDATE: I'm making progress. All the wiring connectors are unplugged. All the coolant hoses are removed. Throttle, TV, and shifter cables are off. Trans cooling lines are disconnected and plugged. Rear brake calipers are removed and zip tied out of the way. Strut tower nuts and cradle bolts are loose. Tomorrow morning, the cradle should be on the ground (hopefully).
I dropped the cradle down onto the legs of the hoist and thought I was screwed. I used 2 floor jacks and 2 bottle jacks in the corners of the cradle to raise it enough to pull the hoist out. Then I lowered the cradle down to the creeper a little at a time. Here's a pic of the cradle down. That's as far as I got today.
I have a lot of cleaning to do to the engine compartment and cradle. So, I'm probably done with this thread. I'll start an new thread about rebuilding the TH125 in a few days. I will need a lot of help with the transmission.
Thanks guys.
[This message has been edited by batboy (edited 09-19-2021).]
I'm not seeing how that Dedenbear part will (can) work any better.
This is an old picture but you can see the 2 water fitting areas on the front of the SBC block. The right leg of the Dedenbear part is pointed in the correct direction but the Left leg would clearly point toward & interfere with the frame rail & the suspension parts. That end of the Dedenear would only work if it was deadheaded & that would force all the coolant thru the right leg. Far from cleaning up the plumbing, Hoses & fittings to make the Dedenbear work would "dirty up" the plumbing.
Archie
Coolant only needs to go in one end. Bank-to-bank distribution is fine or it wouldn't be usable in race cars. It cleans up the plumbing by only requiring one supply connection.
[This message has been edited by Will (edited 09-20-2021).]
Originally posted by Will: Coolant only needs to go in one end. Bank-to-bank distribution is fine or it wouldn't be usable in race cars. It cleans up the plumbing by only requiring one supply connection.
I think only using one leg of the part you are suggesting is going to restrict flow by half.
**** . I thought some of these names here would have been dead by now. Glad to see you all still here.
I'm going to have to pull my K member cause my clutch release arm is stuck from sitting for 10 years. I'm enjoying reading about improvements with water pumps, exhausts and what all.
