New main case

All Models and Years
Post Reply
User avatar
Deadwolf
Posts: 21
Joined: Thu Sep 24, 2020 3:26 am

New main case

Post by Deadwolf »

I've got my current project going and the current engine is fully functional.

I am looking at building from the ground up a new performance engine build. What I am wondering is what is made aftermarket and what isn't?

I know I can get new jugs, pistons, and crank shaft, but what about an aftermarket main case or heads? It sure would be nice to have new parts to start with or even an aftermarket main case and heads that were designed to allow for bigger jugs or a larger stroke. I know these engines are not as popular as the SBC and BBC engines, but if they can make an aftermarket block and heads for the Mark I big blocks (348 and 409 :chevy: ) I figured maybe someone out their has done it for the flat 6.
:ty:
1963 Impala SS convertible project
1963 Monza Spyder project
1963 Impala coupe Pro Street Project
1964 Monza Parts car
1963 Impala hard top sedan parts car

User avatar
Mcwho
Posts: 97
Joined: Sun Mar 25, 2018 3:31 am
Location: DeBary FL

Re: New main case

Post by Mcwho »

I have seen that there are bigger jugs/pistons made by vw. There are resour es for clean used main casses. Think you are outta luck on new one.

Sent from my SM-G965U using Corvair Forum mobile app

1965 Corvair Monza Coupe 110, 4 speed, Liberty Blue

User avatar
bbodie52
Corvair of the Month
Corvair of the Month
Posts: 9677
Joined: Mon Aug 06, 2012 12:33 pm
Location: Lake Chatuge Hayesville, NC
Contact:

Re: New main case

Post by bbodie52 »

This book may be of some help in your quest for performance upgrades and modifications...

In addition to the factory shop manual, this book contains a great deal of performance information about the Corvair. As a teenager I read the earlier version of this book in 1970 and found it to be very valuable and informative. It is a personal favorite.
:link: https://www.amazon.com/Performance-Corv ... +to+hotrod
Image
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible

joelsplace
Posts: 1115
Joined: Wed Oct 13, 2010 12:51 pm
Location: Northlake, TX

Re: New main case

Post by joelsplace »

No one makes cases. There is a guy working on heads but hasn't made the first set yet. ARP makes case studs but you have to call them. Red Sedman at American Pi makes a roller cam setup, an adjustable gear and sells custom fuel injection as well as does machine work. Harland Sharpe makes roller rockers but you'll need extra valve cover clearance. Clark's has aluminum oil pans, valve covers and differential covers. Ken Hand mods differential carriers for 4 spider gears and sells small diameter dual disk clutches. Someone was making a billit stroker crank but I can't remember the source. Lots of others stuff dealing with pistons and rods. Several people do deep seats and other head work.
113 Corvairs, 5 Ultravans and counting
Northlake, TX

User avatar
flat6_musik
Posts: 2419
Joined: Sun Apr 04, 2010 10:03 am
Location: Hesperia, CA

Re: New main case

Post by flat6_musik »

I was pretty amazed when I saw those reproduction 348/409 heads etc. too. There's probably enough good used corvair engine cases out there for the demand now. What's needed is cylinder heads!

User avatar
Deadwolf
Posts: 21
Joined: Thu Sep 24, 2020 3:26 am

Re: New main case

Post by Deadwolf »

bbodie52 wrote:
Sun Oct 04, 2020 7:56 am
This book may be of some help in your quest for performance upgrades and modifications...
Yes I already ordered that book and a couple others that I thought would be useful at this time.

I've found the stroker crank, aluminum cylinders, all the machinists out their doing head work, rods (even light weight aluminum), and other stuff. I've actually found myself on several sites that use the Corvair engine for airplanes and found some neat stuff as well, not sure if all of it would cross over and work, but neat none the less.

My current plan is to get what I have working since supposedly the 150 HP turbo engine was already overhauled to stock specifications. Eventually though like all my projects I start looking for more and I'm thinking with these engines able to be bored and stroked to about 200 cid, I should be able to get a street drivable 250 HP at the crank out keeping a turbo. Lighten the 63 up a little and get myself in that 1 HP to every 10 lbs of car. With what I see available right now I think the biggest issue is going to be finding a turbo that is small enough to spool at 2000 RPM or less, but won't become a restriction by the time I reach 5500 to 6000 RPM. Also though it looks like some people have used roots 471 blowers on these cars, but I think a turbo would better of the two options since my car will already say Turbo.


I'm actually building a 348 that has been stroked to 438 cid for my convertible right now. Only problem with it is everything is expensive if it isn't also used on a SBC or BBC. That build it going to cost me around 18K when all is said and done, already have over 3K in machine shop work and another 3 in the rotating assembly and I still have not bought the heads. I'm thinking I could build a nice corvair motor for around 9-10K
1963 Impala SS convertible project
1963 Monza Spyder project
1963 Impala coupe Pro Street Project
1964 Monza Parts car
1963 Impala hard top sedan parts car

User avatar
flat6_musik
Posts: 2419
Joined: Sun Apr 04, 2010 10:03 am
Location: Hesperia, CA

Re: New main case

Post by flat6_musik »

I'm not sure you could build a turbo motor that you describe, without dropping exhaust valve seats.

66vairguy
Posts: 2173
Joined: Tue Dec 21, 2010 3:44 pm

Re: New main case

Post by 66vairguy »

Just my observations over the years, but I'd suggest re-thinking the turbo engine size. With a modern turbo, fuel injection, computer controlled waste gate, ignition, fuel mixture you can get a good 220HP out of the 145C.I. engine or go with the LM block and crank for 164C.I. Clark's full fine cylinders are strong enough to take the boost. Large cylinders and stroker crank won't be happy with a lot of boost. Fine for high RPM naturally aspirated.

Contrary to common wisdom you don't have to use the big valve 140HP heads for a streetable turbo engine. The smaller valve heads have more material around the valve track and the smaller valves dissipate heat better. Excess heat is a valve seat's nemesis.

GM documented the cooling system was only good for a sustained gross 140HP. At a Corvair convention one of the Corvair engineers was asked why the cooling system was inadequate on turbo cars. He had a logical reply. He said the engine would tolerate full boost for about a minute and by then you be at the maximum vehicle speed and only a reckless person would keep a vehicle at that speed for a sustained period. Basically the cooling system was adequate for handling maximum power for passing or fast starts. At 220HP you'll need alcohol and water spray into the cooling fan inlet while on boost.

Finally the turbo 180HP torque max was about 230 ft. Lbs. That's about the limit for a Corvair transaxle, especially the EM unit. The 66-69 LM car used a higher torque rated four speed. If you install a 4 spider LM differential it can probably handle 250 ft. lbs reliably as the Crown V8 conversion could barely handle 290 ft lbs. IF you were careful with the clutch.

Now if you want a real project. Buy a beat up Crown Corvair V8 conversion (after a few transaxle failures some folks just parked them) and install a later Corvette differential. You can mate different gearboxes to it.

joelsplace
Posts: 1115
Joined: Wed Oct 13, 2010 12:51 pm
Location: Northlake, TX

Re: New main case

Post by joelsplace »

Buy a Nash fan, bell and pulley for vastly improved cooling.
113 Corvairs, 5 Ultravans and counting
Northlake, TX

User avatar
Deadwolf
Posts: 21
Joined: Thu Sep 24, 2020 3:26 am

Re: New main case

Post by Deadwolf »

66vairguy wrote:
Sun Oct 04, 2020 6:45 pm

Now if you want a real project. Buy a beat up Crown Corvair V8 conversion (after a few transaxle failures some folks just parked them) and install a later Corvette differential. You can mate different gearboxes to it.
I was actually looking at this for my parts car, but with the corvette transaxle the transmission ends up between the motor and transaxle and that makes an LS engine, 5 speed transmission, and transaxle 58" from the axle center forward. I'm not sure if enough room exists to put that in even if I am on the shorter side for men at 5'7" tall. Have to break out the tape measure and start measuring for that one, but I have to get the spyder running before I start any more major projects as my 63 Impala pro Street is already a challenge and part of the reason I got the Corvair. I need a little break from the fabrication process and just want to spend some time turning wrenches.
Last edited by Deadwolf on Tue Oct 06, 2020 4:49 am, edited 1 time in total.
1963 Impala SS convertible project
1963 Monza Spyder project
1963 Impala coupe Pro Street Project
1964 Monza Parts car
1963 Impala hard top sedan parts car

User avatar
flat6_musik
Posts: 2419
Joined: Sun Apr 04, 2010 10:03 am
Location: Hesperia, CA

Re: New main case

Post by flat6_musik »

You mean 5'7"...?

User avatar
Deadwolf
Posts: 21
Joined: Thu Sep 24, 2020 3:26 am

Re: New main case

Post by Deadwolf »

flat6_musik wrote:
Mon Oct 05, 2020 8:04 am
You mean 5'7"...?
Oops, yes! I wish I was 6'7".
1963 Impala SS convertible project
1963 Monza Spyder project
1963 Impala coupe Pro Street Project
1964 Monza Parts car
1963 Impala hard top sedan parts car

Post Reply

Return to “Ask your Mechanical Questions here”