Engine rebuild musing, corvair vs 1911 Options

[r3dplanet]

Years ago I was all hot on the idea of dropping a Corvair motor into my 1971 914 when the 1.7 liter eventually pooped out. During that time I've done an enormous amount of work to the rest of the car and overall its in spectacular shape, except the motor which is getting tired. While the current motor is completely clean on the surface I have 90psi in cylinder #3, 140psi on the other three It's starting to leak but it has a fresh D-Jet do over with new parts, wiring, etc. The engine is from 1973 and its an EA code. From what I understand this means that the heads are a newer revision from the early 1.7 heads.

So I'm thinking that maybe over the next winter I'll pull the motor and .. do something.

My goals are good to excellent mileage, reasonable power, low maintenance, high quality. Frankly, I'm happy with the power of the 1.7. It sounds much faster than it is and that's just fine with me. The car is fun to drive and I'm not interested in speed per se.

The reason I got hot over the Corvair motor is because the design is really good in terms of longevity. The early engines had issues with dropping valves and head gasket failure but the later engine (like the 1965 Corsa 140 motor I have sitting on a stand in my garage) did away with that after GM upgraded the engines after 1963. The Corvair engines have hydraulic valves, great power at even the stock rebuild level, and excellent reliability. You can do carbs, Megasquirt, or any of a handful of other fuel systems - only a few of which are really expensive. If you want to go nuts you can throw in six Porsche cylinders/pistons and get a 3.1 liter six. I'm not interested in that, but it's spectacularly cool that one could.

Costs for the Corvair project are a touch murky. I already have the engine, reverse-rotation cam, clutch, flywheel, and adapter plate. Rebuilding the heads to overcome a valve-drop issue costs between $800-$1000, and the engine kit itself is $1100. Fabbing up an engine mount is cheap. What I don't know is the hidden gotchas of this kind of conversion. Figure $500 for a set of carbs or the fuel injection off of Fiero. So $2.5k for the engine and figure some extra for the hidden extras. Perhaps $3000.

On the other hand, I like my 1.7 liter just fine. And from what I understand I can upgrade to a 1911 for not a lot of extra money on top of the rebuild cost - or I could be totally wrong. Scouring this and other websites for engine recipes and costs it looks to me like I'm in for $3000-$4000 just for the parts. Figure in a grand for head work and I'm at $4-5k. While I like the 1.7 and the purist in me (some days I'm a purist) thinks I should keep the car's provenance intact, it's hard for me to justify $5k+ for an 80hp/100k mile motor. So the higher gas prices climb the better of idea this sounds, but the math may say otherwise if the rebuild costs are truly this high. And, perhaps romantically, I'd like the keep the whole car metric.

The mileage argument is certainly in favor of the 1.7 in that I get 30-35 mpg on the two tanks of gas I've ever driven the car through. The Corvair gets maybe 26.

The longevity argument is in favor of the Corvair engine. The engine rebuilder in town says he sees 250k miles on average in between rebuilds vs 100k for the Type-IV.

So I'm undecided. But I figure its better to objectively hash out these ideas in the planning stages rather that get halfway through an engine rebuild and realize that what I'm doing isn't feasible.

Something I'm not at all sure of are the true current facts and figures about each option. The Corvair option has a few mysteries about getting it all configured for the wiring, sheet metal, other unknowns. The 1.7 or 1911 option seems hideously expensive unless my numbers are way off, and they very well could be.

The one argument I'm not interested in is the whole "you have to pay to play" trash. If I want to "play" I'll jump into my fast as hell Barracuda or motorcycle. I do understand the engine rebuilding is not cheap, but I'm not going to be goaded into spending more money than the car is worth on an engine rebuild.

What I AM interested in is your knowledge, experience, and reasoned discussion.

Thanks all. I love this site.

-marcus

[ape914]

I think your cost estimate for the 1.7 rebuild is on the high end. a basic rebuild can be done for a bout half that maybe even less.
Rebuild the heads, maybe a much less depending on how bad they are.I spent less than half that on mine needing new guides, seats, and some welding and machine work.
regrind of the crank was about $75, bearings were about $200, cam (new, Elgin perfromance FI grind) was less than $200,

all depends on how much work is needed on your core.

[r3dplanet]

That's good thinking, and thanks for adding your experience. My numbers do seem to reflect a complete do-over. I suppose its impossible to really know what's up without disassembling the engine. I think I'm just expecting the whole thing to be severely trashed because that's how my luck generally goes, even though I have no reason to suspect that there's hideously wrong with the motor right now.

I think your cost estimate for the 1.7 rebuild is on the high end. a basic rebuild can be done for a bout half that maybe even less.
Rebuild the heads, maybe a much less depending on how bad they are.I spent less than half that on mine needing new guides, seats, and some welding and machine work.
regrind of the crank was about $75, bearings were about $200, cam (new, Elgin perfromance FI grind) was less than $200,

all depends on how much work is needed on your core.

[76-914]

1.7 is bullet proof. keep it in it's power range and it's fine. The bottom half is probably good for another 100k miles. Valve jobs run $800+. P&C's $1200 or $49.99 for Chinese (IMG:style_emoticons/default/happy11.gif)

[rwilner]

Do you really expect to put 100k miles on your 914?

Even if you put 5k miles on your car a year, youre talking 20 years before you'd need a teardown.

IMO the longevity issue should be a minor factor...unless you intend to drive this car as your only car for a long time.

[rwilner]

Double post

[VaccaRabite]

If you have the corviar motor and all the parts to make it work... I'd do that.

You won't need to cut up your car. The engine mount is easy. The hard part is the tin, and that is more frustrating and tedious then hard. You can build a good corvair motor for cheaper then you can build a good T4 and when you are done you have 20 or 30 more HP then the 1911.

Use the corviar "sport" headers (not sure what they are called, but not the "log" header).

The one thing you will get from the 1911 that you will not get from the corvair is cabin heat. At least, not without some engineering, and not using stock 914 parts.

Zach

[Dr Evil]

Where are you getting your prices and what do they include for the corvair parts? (IMG:style_emoticons/default/confused24.gif)

I have rebuilt my engine to 3.1 and it was pretty cheap. To go 3.1 you do not use Porsche P/C, you use T1 VW. A set of 6 is about $400 and needs machined to work. If you just rebuild stock, use a better exhaust as Zach said. There is in depth info and pics in my bus thread.

There are lots of deals on parts on ebay. For induction, getting the tripple weber heads and adapters is probably the best and easiest for power, but it will cost more than stock.

There are also 911 style cooling setups....but I dont know why.

[r3dplanet]

Well, yes.

The numbers and prices are all over the place. One engine builder in town told me that I needed a different crank for a 1911, along with head modifications or new new heads altogether. Another builder gave me similar prices. A well known engine person on this form gave me far, far higher price when I queried a year ago.

The prices I'm getting for the Corvair engine parts are from an outfit outside of Portland a little ways - Corvair Underground. Kits include cylinders, pistons, pushrods / tubes, etc, etc. Pretty thorough. Obviously all of this is without really knowing the condition of either engine, but the point is I need to know where this can go financially so there won't be any awful surprises down the road. Project scope.

Cabin heat would be really nice. There's a gas heater option for lots of dollars, but I think that one could possibly get creative and get heat to work. But there's no way to visualize that without the engine and what-not all in the car. I've seen one other 914 (outside of Coop914's) with a Corvair engine but there weren't a lot of pictures, and all of them were of the exterior.

The more I think about it, the more I'm not sure. Perhaps I've though about it all too much. That's why I'm gathering opinions here. One thing I do have in my corner is a really great machinist who likes my projects.

-m.

[Dr Evil]

Corvair Underground is the highest price place you can go. You do get what you pay for, kind of like RAT for the corvair. But, like the TIV there are cheaper ways to go for those willing to put the time in to search for the deals.

To get an idea of cost, you must first know what your target is. The range is HUGE from stock to exotic. I have exotic but have spent time sourcing places to save money. In doing so, I also spent and am still spending lots of time getting things together. (IMG:style_emoticons/default/dry.gif)

[Jake Raby]

The Corvair is about the only AirCooled engine I'd never own..
I've done some work on them but lots of things just don't make sense.. But that's just me.

[914coop]

Corvair Underground is the highest price place you can go. You do get what you pay for, kind of like RAT for the corvair. But, like the TIV there are cheaper ways to go for those willing to put the time in to search for the deals.

To get an idea of cost, you must first know what your target is. The range is HUGE from stock to exotic. I have exotic but have spent time sourcing places to save money. In doing so, I also spent and am still spending lots of time getting things together.

Do not use corvair underground!!!!, can give you 12 months worth of reasons why and we are still not finished.

[Dr Evil]

Ah, good thing I have avoided them (IMG:style_emoticons/default/smile.gif)

[r3dplanet]

Luckily there's a bunch of places to order Corvair engine parts from. So I'll heed the advice and use them only if necessary. This is always nice to get warnings ahead of time.

914Coop - I'm super interested to see what your experiences were/will be.

[Dr Evil]

A great place to get used parts from is Corvair Ranch. Jeff Stonesifer is the the owner/operator and is a good guy. He uses Clarks catalog for pricing and beats their posted prices. They do engine work as well:
http://www.corvairranch.com/

[Bleyseng]

Easiest thing is to rebuild the 1.7 to a 1911 with a Raby cam and use the Djet. 90ish hp, runs cooler and still will get 35mpg and is stockish. Heat is so nice in the NW since it does rain and gets cold.

I would say 2000-3000 for the rebuild shopping around..and you don't need a new crank and rods for it. Rebuilding the heads correctly is the biggest cost with bigger valves that won't fall out.

[TheCabinetmaker]

properly maintained the 1.7 is as reliable as any engine. I put over 300,000 on mine before its rebuild. A daily driver can rack up 100K in 5 years.

[Lennies914]

Just seen this listing on CL for a set of rebuilt 1.7 heads.
http://sfbay.craigslist.org/scz/pts/3068069669.html

(IMG:style_emoticons/default/beerchug.gif)

[ape914]

1.7 is bullet proof. keep it in it's power range and it's fine. The bottom half is probably good for another 100k miles. Valve jobs run $800+. P&C's $1200 or $49.99 for Chinese (IMG:style_emoticons/default/happy11.gif)

My JE piston and ring set was about $600 for all four. this was a 96 mm (vs 95 mm stock) piston, the 2 liter "big bore" gives 2056cc. The cylinders are stock, bored out 1 mm (bore them AFTER you have the pistons in hand and measured)( PS I have a set of used 2 liter pistons / cylinders for sale in want ads).
This motor runs fine on the stock D-jet, with the Elgin performance cam, made for D-jet, but more power than stock a bit more radical, but idles nicely, smooth acceleration. You may want to spend about $100-$140 on having your injectors flow tested and cleaned if you got used ones. Go with the lighter stainless heat exchangers and a Bursch muffler for more go power.

Note the early 1.7 motors had a lot of power to start with, if you pick a performance cam, and bump the compression, better exhaust, balance etc...they can rock even more. The 1.7 rocker assembly is prefered over the 2.0 rocker assembly even when building a 2 liter.

I had lots of fun in my old 1.7 early 1970 car stock motor guts, ss heat and Bursch exhaust, stock D jet, Pertronix ignition. Great mpg too, low 30's most of time, mid 30's on long highway trips. The handling is where it is at on these cars anyway, fat sway bar, in front, sticky tires, low profile (50 series) lowered, and stiffer rear springs. Then I handled as if on rails.


I'd stick with the type IV motor over the Corvair. Less work, The D-Jet is really nice verses any carb set up as far as drivability and fuel economy. If that is an important goal then a D-jet based solution would be nice (or spend more $ and go aftermarket FI, what's the budget again???)

Also if it matters to you, these cars specially in stockish clean form are increasing in value, and I suspect will continue to do so for some time. , and if resale value is a factor to you, the car would certainly be more desirable as a tastefully pumped up type IV or as a converted 911 six, than it would be with a comparable Covair six. I guess some potential buyers would be more afraid of this uncommon engine swap.

[914_teener]

1.7 is bullet proof. keep it in it's power range and it's fine. The bottom half is probably good for another 100k miles. Valve jobs run $800+. P&C's $1200 or $49.99 for Chinese (IMG:style_emoticons/default/happy11.gif)

My JE piston and ring set was about $600 for all four. this was a 96 mm (vs 95 mm stock) piston, the 2 liter "big bore" gives 2056cc. The cylinders are stock, bored out 1 mm (bore them AFTER you have the pistons in hand and measured)( PS I have a set of used 2 liter pistons / cylinders for sale in want ads).
This motor runs fine on the stock D-jet, with the Elgin performance cam, made for D-jet, but more power than stock a bit more radical, but idles nicely, smooth acceleration. You may want to spend about $100-$140 on having your injectors flow tested and cleaned if you got used ones. Go with the lighter stainless heat exchangers and a Bursch muffler for more go power.

Note the early 1.7 motors had a lot of power to start with, if you pick a performance cam, and bump the compression, better exhaust, balance etc...they can rock even more. The 1.7 rocker assembly is prefered over the 2.0 rocker assembly even when building a 2 liter.

I had lots of fun in my old 1.7 early 1970 car stock motor guts, ss heat and Bursch exhaust, stock D jet, Pertronix ignition. Great mpg too, low 30's most of time, mid 30's on long highway trips. The handling is where it is at on these cars anyway, fat sway bar, in front, sticky tires, low profile (50 series) lowered, and stiffer rear springs. Then I handled as if on rails.


I'd stick with the type IV motor over the Corvair. Less work, The D-Jet is really nice verses any carb set up as far as drivability and fuel economy. If that is an important goal then a D-jet based solution would be nice (or spend more $ and go aftermarket FI, what's the budget again???)

Also if it matters to you, these cars specially in stockish clean form are increasing in value, and I suspect will continue to do so for some time. , and if resale value is a factor to you, the car would certainly be more desirable as a tastefully pumped up type IV or as a converted 911 six, than it would be with a comparable Covair six. I guess some potential buyers would be more afraid of this uncommon engine swap.

(IMG:style_emoticons/default/agree.gif)