911 engine conversion
 

I must get asked at least twice a week “Why would you do such a thing? Ruin a perfectly good 911 by putting a Subaru Engine in it “ The answer is simple, I think of these cars as “Art in motion” but from a maintenance stand point they’re the Devils Advocate!

I have owned several 911s ranging from 1971-1978 and only one of them ever cost me less than $3000.00 a year to keep running, most people in my position do not have access to unlimited financial resources, so they use their Porsche as interior garage ornaments, starting them up every 3 months and backing them out onto the driveway to give them a bath or for a quick Saturday drive of less than a 100 miles, then back in the garage they go. Why? Because none of us want to deal with maintenance issues or the cost associated with them.

My father owned a Body Shop since the day a was old enough to walk, growing up in this environment, I learned that if you don’t like the way something is designed you change it. The Holdbrook Motorsport conversion for Porsche 911 has taken me 3 years to perfect, here is why it’s such great conversion.

First of all I should point out an engine rebuild on a high mileage 911 will set you back about $7,000.00 on average, usually confirming your fears that the engine rebuild will cost about what the complete car is worth, then you must consider “do I want to spend an additional $7,000.00 on my garage ornament? That is usually the last nail in the Coffin of your 911 project.

While the guys that do 911 small block Chevy engine conversions have their heart in the right place, They have some fundamental problems with their conversions,

You have to cut the nose of your 911 out to install a Radiator, this totally offends Porsche owners of all financial backgrounds and radically alters the Porsche.

I have done this radiator conversion twice an it’s a lot more involved than I would want to get myself into if I were a novice, and it’s very time intensive, around a week just for Radiator mounting, with some Kits it’s necessary to cut the gas tank.

With a Holdbrook Motorsport Conversion - Complete radiator mounting takes about 2 hours, you cut nothing, and the radiator mounts in the engine compartment and can swing up or down for easy engine maintenance and utilizes “Ram Air” through the rear deck lid Grill allowing the vehicle to retain it’s stock appearance and structural integrity.

With a small Block Chevy Conversion it is impossible to use this radiator mounting system, The engine itself will not fit unless you take the front off of it and run the Alternator , Water Pump, AC Compressor off a modified belt system. There is also a rear weight issue, our Chevy LT-1 with aluminum intake and heads, weighed in at 575 lbs. that’s without exhaust manifolds or mufflers, a Turbo Porsche engine weighs right at 500 lbs. When I enquired about a handling issue I was told “ You learn how to drive it with the extra weight, it’s Great”, Great? I can teach an elephant to use a skate board, but it still doesn’t make it right.

The other problem I had with the small block Chevy Conversion was after you had spent a month piecing your 911 together it sounded like your brother-in-law’s pickup.

With the Holdbrook Motorsport Conversion your engine looks and sounds like a Porsche, the 3.3 liter fuel injected 230 hp 24 valve Boxer engine weighs in at 384 lbs. You don’t have to dismantle the engine to make it fit the engine Bay,and you can be driving your completed 911 conversion in three days. Best of all, you can sell that high mileage 911 engine to someone who has more money than common sense and use the money to off set the price of the conversion. CHECK IT OUT !
www.holdbrookmotorsport.com


HoldbrookMotorsport.com

This sounds like an advertisement, but is intriguing enough for me to let it stay for the moment...

I always thought that the Honda V-TEC engines were the top god these days...

-Wayne

repost

For the price, Id rather rebuild a air cooled motor or join the 3.6 gang.

Re: 911 engine conversion
 

And from his website: "New!! Complete Conversion Kit for $5925.00 - you supply the Engine! Kit includes:"

Hmmm, $6000 and I still need to come up with an engine. Tell me again how this is cheaper? Is this some of that governmental "fuzzy math?"

I'll admid that the thought of a hot-rodded NA 2.5L 4V Subaru engine has some draw for a low displacement light weight "run-about".

Something with a bit more guts would be the ubiquitos turbo version or the flat 6's, though I'm sure the 6's are a lot harder to find.

Wayne,
You are far too diplomatic...I think its a blatant ad. The shop is in Montana and the poster also lists his location as Montana...it reads just like copy or an infomercial.

Kurt,
I agree...seeing how my SC motor has 190,000, and if the rebuild gets another 200,000 miles (for less money than the conversion), the combined total of the kit and engine would have to last more than 500,000 miles to be worth while.

Seely,
Although I have posted in the past that the conversion sounds like a very cool alternative, the cost just does not make sense. Also, I think you are making a HUGE generalization about the 911 owners on this board. Most guys here work on their rides (to include all aspects...not just washing and waxing) and in a lot of cases drive the pi$$ out of their cars. Truth be known, I spend more money on my car for little things that I fix for my own reasons...the car itself has been pretty cheap to maintain becasue the parts were so well engineered in the first place. Heck, I JUST repalced the original, 20 year old, rear shocks...190,000 miles and they finally gave up the ghost. Funny thing is my buddies busted my nuts because I had to pay SO much for them ($125/each...I figured it was a bargain). Of course they work great, and if they last me even 15 years, I'm sure my firends will have soaked at least that much dough into spongy, crappy monroe shocks.

just my $.02

R/
Dustin

A 3.3 liter Engine costs about $3500.00 so together with our Engine conversion kit total cost is around $9500.00. The Engine rebuild on the Porsche Engine will average around $7000.00.

Then if it needs a new Muffler, another $500.00 plus installation, Then
you will have to pay the Mechanic to set up the Engine so it runs
smooth.( going rate is $95.00 hr.) average bill is $400.00, but if your
one of the unlucky one's who has worn out mechanical injection and
carburetors, the fun is just beginning! After the Mechanic has finished
up and handed you your complementary jar of Vaseline,and sent you on yourway, its a given that you will be back every 3 months to adjust the
carburetors.( average $400.00 per visit) or you can just not drive it.
Add in all the future maintenance costs and parts replacement and I would take the Engine conversion option every time, ITS COMPLETE! average maintenance cost $50.00 per year, plus you have true fuel injection and 230 horses!
This Engine is non- interference which means if you ever
loose a timing belt while you're driving it doesn't ruin your Engine
unlike most other Engines! Finally, the Porsche Engine is oil cooled, I
have personally purchased two 911s that were totaled because of Engine
fires as a result of backfiring while they were being started, igniting
an oily engine and goodbye Porsche! Replace the Porsche Engine and sell it, put the money toward your conversion and enjoy your car!


---

Don't let the door hit you in the ass on the way out...

If a 911 owner is too naive to adjust their own carburetors, then they certainly won't be doing an engine swap.

This doesn't make any sense...

-Wayne

Where in Montana are you located?

Western Montana - Missoula

I wish my customers would come back every 3 months for a carb adjust.......

Here's an idea, if you really wanted a neat conversion why not the 2.7 Porsche Boxter? I figure if the can cram it between the seats and the truck on a Boxter it will fit in the back of a 911. Sure the motors are a little hard to come by and a bit pricey but it's still a Porsche flat six. At least the V8 guys can brag about all the HP and torque they can make, this subby sway addresses percieved maintenance costs. To me the smart money would be to build a complete EFI intake and system like this one. http://www.edelbrock.com/automotive/autopartsphotos/fuel_inj/3500_callouts.gif

Seems to me that two manifolds (small and large runner versions) would cover the 2.0 all the way to the 3.0 and solve a lot of people a lot of problems as well as making things like turbos and superchargers more easy to install.

My .02c

One other thing I should point out, I LOVE V8 engines. I'm one of those guys who can tell a small block Ford from a small block Chevy half a mile away just by the sound of the exhaust so you're never gonna convince mt that a flat four subaru will sound even close to a real 911 engine. As much as I love V8's they just don't belong in a 911 and neither does any other engine for that matter. To me the distinct sound of a 911 with sport exhaust is a big part of the pleasure in owning one. If I need more reliability from a 911 I'll just put a newer engine it it but for right now my carbed 3.0SC engine suits my '66 just fine and believe me the exhaust gets rave reviews from everyone whos ridden in it as well as a lot of bystanders.

That was an add.

I thought this forum was to ask questions, get answers, learn how to, etc. I wouldn't mind if post was a documentation with pictures of how you did it to your Porsche, but if it's an add on how you can purschase the parts from someone else, then what respect is there for our host?

A 3.3 liter Engine costs about $3500.00 so together with our Engine conversion kit total cost is around $9500.00. The Engine rebuild on the Porsche Engine will average around $7000.00.

>Then if it needs a new Muffler, another $500.00 plus installation,
Are subaru exhausts free? You are making quite a stretch here as to needing a new muffler

>Then you will have to pay the Mechanic to set up the Engine so it runs smooth.( going rate is $95.00 hr.) average bill is $400.00

Huh? Most guys on this site are DIYers...why would they rebuild their own motor and THEN take it in to be "set up" to run smoothly? Again, you just added an arbitrary $400 bones to the total when its a non-issue.

>but if your one of the unlucky one's who has worn out mechanical injection and carburetors, the fun is just beginning! After the Mechanic has finished up and handed you your complementary jar of Vaseline,and sent you on yourway, its a given that you will be back every 3 months to adjust the
carburetors.( average $400.00 per visit) or you can just not drive it.

Okay, this is just ridiculous. I think the majority of 911's on this board run CIS or Mototronic, so your $1200/year cost to adjust the carbs or MFI is out to lunch. Besides, I've heard of a lot of guys getting their MFI dialed in and never having to mess with it for a LONG time.

>Add in all the future maintenance costs and parts replacement and I would take the Engine conversion option every time, ITS COMPLETE! average maintenance cost $50.00 per year, plus you have true fuel injection and 230 horses!

Again, just another supposed expense...you mean like oil changes etc? Do Subaru engines not require replacement parts?

>This Engine is non- interference which means if you ever
loose a timing belt while you're driving it doesn't ruin your Engine
unlike most other Engines!

Non-issue with 911 engines with the tensioner upgrade...about $400. The chains just don't break. Basically, this sounds like a scare tactic suggesting that we're living on borrowed time until a chain breaks.

>Finally, the Porsche Engine is oil cooled, I have personally purchased two 911s that were totaled because of Engine
fires as a result of backfiring while they were being started, igniting an oily engine and goodbye Porsche!

Yes, they are oil cooled, and I have to admit that oil dripping on hot surfaces can lead to engine fires...actually mine suffered a small one about 8 years ago due to a small oil leak that became a big one at the wrong time. However, having said that, ALL engines are potentially fires waiting to happen. Last I checked the Subaru also runs on gas and uses oil.


>Replace the Porsche Engine and sell it, put the money toward your conversion and enjoy your car!

Dang! Too late, I ALREADY enjoy my car. Again, I think the Subaru engine (6 cyl) would make a pretty cool conversion, but with the costs involved (essentially $10,000), I think you could do as good or better putting in a 964 motor for the same mileage and money. I will admit that most Japanese engines cost very little to maintain, but I'm not so sure that the 911 guys on this board simply leave their cars in the garage for fear of maintenance costs....heck, it ain't like operating a helicopter.

R/
Dustin

I haven't pulled it because it hardly seems like a reasonable swap ($$$) to me...

-Wayne

he used the word "our", so that should confirm that he is at least a paid spokeman :)

Guys, all I'm saying is this, Not all of us are Porsche mechanics but
we do love the cars! I'm not advocating that everyone should do this! its
an option and the tech bulletin says " engine conversion" not " guys
don't change a thing"

Example- my 1976 was totaled due to an engine fire, I was told by
porsche mechanic's that I could purchase another 2.7 liter for around
$2700.00 and do a rebuild on that Engine, grand total around $9000.00 but...

in the same breath was told " their not a desirable engine because of the
magnesium case and problems with the head studs" that I really should
look for a 3.0 liter. In Seattle I was #14 on a list for a used 3.0 that
would have at least 200,000 on it.( cost around $5000.00) then I was told it would more than likely need a rebuild ( another $7000.00) that is if I wanted to wait around for a year. My 1976 911 is worth in reality around $7500. With this conversion we don't cut the cars up, you go from 150 horse power ( 2.7 liter Porsche engine ) to 230 horse power, no more oil leaks, and in my case ,no more Engine fires! I was even able to sell my fire damaged 2.7 liter for $1700.00 and off set the cost of the conversion.

Again Guys, I'm just offering an option, that dosen't cut the cars up and the car can be returned to stock very easily which is not the case with most conversions. This is my passion and provides an alternative way to keep one's older 911 on the road.

6 cylinder subes kick butt, and i wouldn't mind one in my watercooled vanagon pickup, but in a 911, there's just something wrong with that.