New guy adding EFI and a turbocharger to a '73 H-code

[Looftie]

Hi all. I'm a long time lurker and now a new member to this great forum. My background is mechanical engineering and I've been tinkering with cars since 1992. My car is a 1973 Cougar XR7 convertible ('71 front and rear bumpers/trim). Hopefully you can look past the outer sheet metal and pretend its a Mustang underneath.

Before lung implant



With breathing aid



I've owned my heap since 1994 or so and had it in storage since 2000 when it started running rough. I got it out a couple of years ago and diagnosed a dead cylinder. The car ran hot for a long time and it ends up that I pushed the #8 exhaust valve seat partway into water jacket. That happened because I unwittingly installing a 351W stat and drove the snot out of it.

Anyway, I've done a few things over the last 18 months or so. Here's a quick run down:

- installed correct Robertshaw t-stat (replacing it with aluminum restrictor plate and 351W stat right now)

- replaced all brake lines with stainless pre-bent tube and stainless braided hose (added line-lock to rear wheels and adjustable proportioning valve)

- rebuilt factory power brake booster w/ new master cylinder

- rebuilt/upgraded the power steering system (quick ratio gearset, larger torsion bar, all new bushings, upgraded poly ragjoint, ball joints and tierods)

- replaced factory fan with Zirgo aluminum shroud (actually fits our radiator core with minor trimming), Spal 16" electric fan and relays

- upgraded alternator to 140-amp GM SI style 3-wire unit (zero cutting of car's harness, great upgrade that is easy to do)

- rebalanced drive shaft with new Dana-Spicer U-joints

- replaced speedo cable/gear (leaked badly)

- replaced turd Crower Baja Beast cam (0.476"/0.484" lift, 258º/264º, 4400RPM redline) with Crower Ultra Beast cam (0.528"/0.540" lift, 278º/284º, 5500RPM redline)

The engine is a mild rebuild with about 20-30k miles on it. It was done when I was a snot-nosed teenager, had no money and knew little about engines. I know it has a Seal Power rebuild kit with 30-over cast pistons, stock rods, 10/10 turned stock crank and little else. I assume compression is near stock (8:1 or so).

Since the rebuild, I've replaced the horrible RV cam/spring combo that my father directed the machine shop to pick for it and upgraded the exhaust valves to stainless 1-piece units. Heads are getting a mild milling right now so I can install ARP head studs and Cometic MLS head gaskets.

My goal is 500 to the wheels through an FMX (650ish crank HP). I'd like to do it on pump gas and 2v heads. If that isn't possible, I will switch to E85 and try again. My fuel system is/will be (still buying stuff) E85 compatible (stock 43 year old tank has been lined). When/if the block goes, I'll either run a grouted block or an aftermarket one. When the FMX goes, I plan to install a built 4R70W since the wife refuses to let me teacher her how to drive a stick and thus wont let me install a "man pedal".

To achieve that ambitiously high wheel horsepower number, thus far I've enlisted the help of Accel (DFI Gen 7), Aeromotive (Phantom Flex 450LPH in-tank fuel pump conversion kit), Turbonetics (75mm T-4 turbo) and Tial (v60 wastegate) among others.

I won't cut/drill the body unless I absolutely have to. I also want to retain all factory accessories (A/C is going back in as well). This far in, except for the battery, I think it is still possible.

I have a pretty detailed build thread over on the Turbo Forums. It needs some clean up and updating so I'll probably edit and update it over here in a new build thread. I'd love input (positive and negative) on my approach, parts combo or any other aspect of my project.

Any other turbo 351c or EFI 351c guys on here?

 

[Jeff73Mach1]

Nice looking mustang under the sheetmetal

There are a few efi guys around here.

You said you have line locks to the rear wheels-that is backwards, Line locks are to lock the front wheels while doing a burnout. Perhaps it is a typo-if not it is something to correct.

Running an engine til it blows or a transmission until it fails is really a bad idea. Generally what happens is when one fails it causes lots of damage to the other as well. It leaves you stranded and with a tow bill. An FMX is a good transmission, but if you get 500 RWHP you will destroy it quickly.

It sounds like your base engine is basically stock in nature. If your tune on the EFI and turbo is not correct, those cast pistons will melt fairly quickly. Personally I would overbuild the bottom end for your goals. The 2V heads will be somewhat limiting-though the turbo will help get past that.

With the low mileage on the rebuild, you could likely just hone the cylinders and put in some fresh forged pistons, along with any oiling mods the block is going to get to handle nearly triple the current horsepower. I would add main studs while you are at it and consider getting the rotating assembly neutrally balanced and using an SFI certified balancer.

Make sure you read up on the cleveland oiling system and figure out what if any mods are necessary for your project. One problem inherent to these engines is the oil return from the heads can hold oil that should be returning to the bottom end. Gaskets must be matched to the return holes so as to cause ZERO constriction.

Blocks are getting harder to find, I wouldn't shortcut such a build.

Good luck and add a link to your other thread, I'd like to read it.

 

[Mister 4x4]

Hey Looftie - welcome from West Texas! ::thumb::

Good lookin' car! My neighbor had a white one I lusted after when I was a kid (before I discovered one of my Mom's friends had the '71 Mach 1, that is).

Jeff's speakin' the truth - build the whole engine and drivetrain to handle the extra power of the add-ons you're going with.

I have an Edelbrock E-Street EFI ready to go into mine - after I drive it around with the Edelbrock 1406 Performer carb to break it all back in, that is. Mine's just recently gotten to the 'almost ready to drive' level from being a pile of rust in the shape of a Mustang when I got it.

Good luck with your build - hope you find what'cha need here. Glad to have ya! ::thumb::

 

[Looftie]

Nice looking mustang under the sheetmetal

There are a few efi guys around here.

You said you have line locks to the rear wheels-that is backwards, Line locks are to lock the front wheels while doing a burnout. Perhaps it is a typo-if not it is something to correct.

Running an engine til it blows or a transmission until it fails is really a bad idea. Generally what happens is when one fails it causes lots of damage to the other as well. It leaves you stranded and with a tow bill. An FMX is a good transmission, but if you get 500 RWHP you will destroy it quickly.

It sounds like your base engine is basically stock in nature. If your tune on the EFI and turbo is not correct, those cast pistons will melt fairly quickly. Personally I would overbuild the bottom end for your goals. The 2V heads will be somewhat limiting-though the turbo will help get past that.

With the low mileage on the rebuild, you could likely just hone the cylinders and put in some fresh forged pistons, along with any oiling mods the block is going to get to handle nearly triple the current horsepower. I would add main studs while you are at it and consider getting the rotating assembly neutrally balanced and using an SFI certified balancer.

Make sure you read up on the cleveland oiling system and figure out what if any mods are necessary for your project. One problem inherent to these engines is the oil return from the heads can hold oil that should be returning to the bottom end. Gaskets must be matched to the return holes so as to cause ZERO constriction.

Blocks are getting harder to find, I wouldn't shortcut such a build.

Good luck and add a link to your other thread, I'd like to read it.

Your points are all valid and sound advice to anyone reading this thread.

It might seem unorthodox but I intentionally installed the line-lock on the rear brakes so I can engage it before I hit the brake pedal. Stick guys have to have it on the front but autos can do it either way. Instead of holding line pressure, mine will block pressure to the rear while I stand on the throttle and brake pedal. I’m more comfortable doing a burnout with my foot still on the brake pedal. If I absolutely hate it this way, it should be pretty easy to redo (I did this stuff in small, copper-nickel brake lines).

In the interest of brevity (not my strongest suit), my first post probably came off as a bit reckless with my car/money. I definitely, am not. The EFI/turbo is going to be a slow and gradual transition into boost. I hope to get this one running on my own but I am very fortunate to have the support of moderately well-known EFI guru Scott Clark (a local guy for me) if I get stuck or when it comes time to dial things in on the dyno.

The stock head gaskets, head bolts and 2-piece exhaust valves were obvious weak links that didn’t cost too much to address. The cast pistons are another issue. I don’t have the funds right now to redo the bottom end so I am going to try to be careful. It’s definitely a roll of the dice. I think the crank and rods will be ok since I am not revving past 6k.

I’m trying to approach this as a case study of sorts to see what the 2v heads on a near stock short block can do. Unless they prove to be massively detonation-prone, I think they might actually support this power goal on gas. If detonation is too problematic on pump gas, I certainly think they can do it with E85. I am going to watch AFRs like a hawk and probably tune it a bit fat even for a force induction application (God bless Innovative Motorsports and their LC2/LM2 widebands).

The oil system is something I’m still researching. I’ve read a bit on the shortcomings of the 351c oiling but most if not all problems were in the context of higher RPM applications. With what I have reciprocating in my block (mostly stock stuff), 5500-6000 rpm is all I planned to push it.

If everything holds together, the trans and short block will be replaced as soon as funds are available. That is my stretch goal. Until then, it was my hope to dabble in EFI/boost, at lower power levels if I have to.

 

[DK73]

Welcome from Denmark[emoji6] Regards DK73

Sent from my iPad using Tapatalk Regards DK73

 

[jbojo]

Welcome from TriCities WA.

 

[OMS]

Welcome from Ohio

Don

 

[LCB1]

Welcome from Colorado

 

[mach71351c]

Welcome from San Diego.

 

[Jeff73Mach1]

I didn't mean to sound critical. I definitely understand using what you have as a test bed. By going to forged pistons, you could use a pop up piston to address open chamber detonation problems. Since your block is relatively fresh, a tear down and rebuild can be done without a lot of machine work, but I know that not everyone has the means to do everything they want all at once.

On the plus side, I can tell you that a stock block can handle the power levels you seek as I am right there but normally aspirated with a 393 stroker at 11.5 to 1.

When you get ready to build your final engine, a forged crank stroker bottom end would make you goals much easier to reach.

 

[mrmach1]

Welcome from Massachusetts

 

[mweeps]

Welcome from West Virginia!

 

[jpaz]

Hello & Welcome from Michigan!

 

[luxstang]

::welcome:: from Luxembourg, Europe!

No need to pretend. That's a nice car as it is.

 

[goodnigh]

Welcome from northern California.

mike

 

[Boss1Ray]

Welcome from Oklahoma.

Ray

 

[Mustang Dynasty]

Hi all. I'm a long time lurker and now a new member to this great forum. My background is mechanical engineering and I've been tinkering with cars since 1992. My car is a 1973 Cougar XR7 convertible ('71 front and rear bumpers/trim). Hopefully you can look past the outer sheet metal and pretend its a Mustang underneath.

Before lung implant

With breathing aid

I've owned my heap since 1994 or so and had it in storage since 2000 when it started running rough. I got it out a couple of years ago and diagnosed a dead cylinder. The car ran hot for a long time and it ends up that I pushed the #8 exhaust valve seat partway into water jacket. That happened because I unwittingly installing a 351W stat and drove the snot out of it.

Anyway, I've done a few things over the last 18 months or so. Here's a quick run down:

- installed correct Robertshaw t-stat (replacing it with aluminum restrictor plate and 351W stat right now)

- replaced all brake lines with stainless pre-bent tube and stainless braided hose (added line-lock to rear wheels and adjustable proportioning valve)

- rebuilt factory power brake booster w/ new master cylinder

- rebuilt/upgraded the power steering system (quick ratio gearset, larger torsion bar, all new bushings, upgraded poly ragjoint, ball joints and tierods)

- replaced factory fan with Zirgo aluminum shroud (actually fits our radiator core with minor trimming), Spal 16" electric fan and relays

- upgraded alternator to 140-amp GM SI style 3-wire unit (zero cutting of car's harness, great upgrade that is easy to do)

- rebalanced drive shaft with new Dana-Spicer U-joints

- replaced speedo cable/gear (leaked badly)

- replaced turd Crower Baja Beast cam (0.476"/0.484" lift, 258º/264º, 4400RPM redline) with Crower Ultra Beast cam (0.528"/0.540" lift, 278º/284º, 5500RPM redline)

The engine is a mild rebuild with about 20-30k miles on it. It was done when I was a snot-nosed teenager, had no money and knew little about engines. I know it has a Seal Power rebuild kit with 30-over cast pistons, stock rods, 10/10 turned stock crank and little else. I assume compression is near stock (8:1 or so).

Since the rebuild, I've replaced the horrible RV cam/spring combo that my father directed the machine shop to pick for it and upgraded the exhaust valves to stainless 1-piece units. Heads are getting a mild milling right now so I can install ARP head studs and Cometic MLS head gaskets.

My goal is 500 to the wheels through an FMX (650ish crank HP). I'd like to do it on pump gas and 2v heads. If that isn't possible, I will switch to E85 and try again. My fuel system is/will be (still buying stuff) E85 compatible (stock 43 year old tank has been lined). When/if the block goes, I'll either run a grouted block or an aftermarket one. When the FMX goes, I plan to install a built 4R70W since the wife refuses to let me teacher her how to drive a stick and thus won't let me install a "man pedal".

To achieve that ambitiously high wheel horsepower number, thus far I've enlisted the help of Accel (DFI Gen 7), Aeromotive (Phantom Flex 450LPH in-tank fuel pump conversion kit), Turbonetics (75mm T-4 turbo) and Tial (v60 wastegate) among others.

I won't cut/drill the body unless I absolutely have to. I also want to retain all factory accessories (A/C is going back in as well). This far in, except for the battery, I think it is still possible.

I have a pretty detailed build thread over on the Turbo Forums. It needs some clean up and updating so I'll probably edit and update it over here in a new build thread. I'd love input (positive and negative) on my approach, parts combo or any other aspect of my project.

Any other turbo 351c or EFI 351c guys on here?

At 165,000 miles had it rebuilt and modded widening oilers as well convert from q-code hydraulic lifters to solid lifters and from the 8.6 compression to 9.5 and told with an oil change over w/XADO can boost that compression to the closest like the q-code in the 1970 mustang mach 1(10.0:1), change over from 3.00 or 3.27 by the time I picked it up to find rear axle ratio of 3.5:1 but as it had 2 barrel intake manifold on the 650 holley boosted the torque/lbs to 289lbs at @ 350hp out of the engine but having to always readjust the air fuel mix and like shake the car apart on jack rabbit starts did a conversion over to the Edelbrock Air Gap 4 barrel intake manifold set up for an EFI(Holley Avenger w/700cfm 4 barrel carb-self learning system on that Cleveland) and further with a stiffer clutch assembly called a Ram Clutch for immediate response in take off w/limited slip posi and anti hop set up in the rear as well in the middle of a monolith leaf springs like the heavy duty Gymkana suspension had on the early corvette.(L-88, 82.... high performance models)And as always, supplied mega photos on my photo album. Hmmm-seen some awesome intercooled bi-turbos w/sprayer technology out there but just not on this years mustang Clevelands but that set up should produce a@ 650 hp or further w/modding the Cleveland inti a408 ci. Guy w/out an EFI but w/73 vert w/@ 20,000 into his w/408 mod as well Nitro set up has that hp. Dan Herberth, President of Pig Vicious Racing on face boo(wasan all mustang race club but just opened up to other racers) out of Glassboro, NJ think will do the quarter in just excess of 7 seconds that to run it on the (ATCO) track had to have a roll bar installed in the rear seat.

 

[mach1000]

Welcome! Nice another Cougar guy! Check out my pics me and my family have a couple 7173 cougar along with our 7173 mustangs. One has a 4.6 modular engine in it.

 

[Don65Stang]

Welcome. Looks like a very nice "mustang". No worries we like the big cats too.