Honda B20 turbo in corvair

Non-Traditionally Powered Corvairs
MikeDTuning
Posts: 89
Joined: Wed Jul 16, 2014 6:39 pm

Re: Honda B20 turbo in corvair

Post by MikeDTuning »

its currently sideways in the rear of the car, Honda motors use very small rads from the factory, so its easy to make up for the lack of airflow, with some extra coolant capacity

Image
Honda B20 turbo powered corvair. Is it the first honda powered corvair out there?
MikeDTuning
Posts: 89
Joined: Wed Jul 16, 2014 6:39 pm

Re: Honda B20 turbo in corvair

Post by MikeDTuning »

Update,

ive put around 800 miles on it since the swap, only minor bugs to report

-first, and most major one had to do with how i ran my fuel lines, i had a vapor lock issue because i recirculated the fuel out of the rail, back into the system to quickly. this causes the fuel to get excessively warm, and thus after a few times though the rail, vaporize.
the solution was to return the fuel back to the fuel tank, thus cooling it down, before its return flight to the engine. on a more interesting note, This also DRAMATICALLY cooled the intake manifold temperatures. which in turn keeps the cylinder temperatures down i was seeing a decrease of around 20 degrees Fahrenheit on my intake manifold during normal highway cruising. i feel like on a stock motor corvair some sort of re circulation fuel system could help lower engine bay temperatures

i love driving this car, its funny how much a modern rev happy honda motor seams to be a great fit for this car, cruising at 80mph is no problem because the motor just sings along at higher rpms The smaller, very quick spooling turbo provides great low end torque, and the rev happy B-series motors makes the car a riot to drive. Also, on my 200mile round trip i recorded over 30mpg. Love hondas, or hate them, there is no denying how well this motor works, in this car.



Next on the list is to revise my temporary (but well functioning) radiator set up, and make the wiring prettier

More updates to come

Mike d
Honda B20 turbo powered corvair. Is it the first honda powered corvair out there?
User avatar
Allan Lacki
Posts: 753
Joined: Sat Mar 13, 2010 3:06 pm

Re: Honda B20 turbo in corvair

Post by Allan Lacki »

Hi MikeD, Please keep the updates coming. It would be great if, some day, you would write an article on this project for publication in the CORSA Communique or CORSA chapter newsletters. Question: What are you using for a pilot bushing? Is it an Oilite bronze bushing, like a stock Corvair pilot bushing, or is it a Honda pilot bushing? I would imagine a Honda pilot bushing is a roller bearing or perhaps a ball bearing. Al ::-):
MikeDTuning
Posts: 89
Joined: Wed Jul 16, 2014 6:39 pm

Re: Honda B20 turbo in corvair

Post by MikeDTuning »

the stock honda pilot bearing fit pefectly, both honda, and GM used the same .590 (or .591) input spline from the trans. Its a nice coincidence. Honda throw out bearing also fit perfectly over the corvair transmissions bearing shaft (i am sure there is a more technical name)

i was really lucky in how many things kinda just fit. i was expecting to fabricate a lot more.
Honda B20 turbo powered corvair. Is it the first honda powered corvair out there?
MikeDTuning
Posts: 89
Joined: Wed Jul 16, 2014 6:39 pm

Re: Honda B20 turbo in corvair

Post by MikeDTuning »

Not often i ask for help from the forum, However i am having an ongoing issue with gear oil leaking onto the clutch, This happened on the old stock motor as well.

while it was apart last, i replaced the seal around the input spline, but its still leaking, Are there any tricks to make this work for when i pull it apart again, i am getting tired of leaks!
Honda B20 turbo powered corvair. Is it the first honda powered corvair out there?
User avatar
davemotohead
Corvair of the Month
Corvair of the Month
Posts: 1171
Joined: Tue Aug 10, 2010 10:37 pm
Location: rosamond california
Contact:

Re: Honda B20 turbo in corvair

Post by davemotohead »

I assume you are talking about the input shaft seal inside the diff snout, did you test fit the seal over the input shaft to make sure the seal was the correct one? did you also install the split ring keeper that holds the seal in place? I coat the OD of the seal with gaskacinch where it contacts the ID of the shaft as well because sometime's gear lube will get past the seal on the outer edge, Check the input shaft seal area as well for wear.
MikeDTuning
Posts: 89
Joined: Wed Jul 16, 2014 6:39 pm

Re: Honda B20 turbo in corvair

Post by MikeDTuning »

i am not sure about the split ring keeper, i will look into this more. Is there a visual of this installation anywhere online? if i pull the trans out again, i want to make sure its for the last time
Honda B20 turbo powered corvair. Is it the first honda powered corvair out there?
User avatar
azdave
Corvair of the Year
Corvair of the Year
Posts: 2095
Joined: Fri Dec 11, 2009 1:27 pm
Location: Phoenix, AZ

Re: Honda B20 turbo in corvair

Post by azdave »

Here's a few pics from the web. A few of these show cracks and damage to the snout from people who didn't know the proper way to pull an engine.
corvair cool stuff 072.jpg
IMG_0811[1].JPG
corvair cool stuff 075.jpg
CIMG1482 (Small).JPG
Dave W. from Gilbert, AZ

66 Corsa 140/4 Yenko Stinger Tribute
66 Corsa 140 Coupe w/factory A/C
65 Monza 4DR 140/PG w/factory A/C
65 Monza 4DR EJ20T/5
64 Greenbrier 110/PG, Standard 6-Door
User avatar
bbodie52
Corvair of the Month
Corvair of the Month
Posts: 11872
Joined: Mon Aug 06, 2012 12:33 pm
Location: Lake Chatuge Hayesville, NC
Contact:

Re: Honda B20 turbo in corvair

Post by bbodie52 »

MikeDTuning wrote:Not often i ask for help from the forum, However i am having an ongoing issue with gear oil leaking onto the clutch, This happened on the old stock motor as well.

while it was apart last, i replaced the seal around the input spline, but its still leaking, Are there any tricks to make this work for when i pull it apart again, i am getting tired of leaks!
These differential throw out bearing shafts have been a known weakness for some time. They are machined castings and can be damaged if leverage is applied when separating the transaxle from the engine. The input shaft itself has splines at both ends, and when separating the differential the larger end can remain embedded in the clutch disc and pilot bushing, while pulling free from the transmission. This leaves a 23" shaft protruding from the clutch assembly, while the heavy differential is being pulled away. It must be pulled straight back until it clears the input shaft. If the angle varies, lateral pressure may be applied against the side of the throw out bearing shaft, sometimes causing it to fracture or crack.

Image

Image

Image

Although not easy to replace (requires dismantling of the differential) the Clark's replacement is not a machined casting, but is machined as a solid steel component which is much stronger. It also is machined with room for two seals, to reduce the chance of differential lubricant from leaking into the clutch area.

:link: http://www.corvair.com/user-cgi/catalog ... N&page=124
Image
Part number C7463: THROW OUT BEARING SHAFT FOR 2 SEALS NEEDS(2)SEALS-60-63=C494,64-69=C495 & 1 C1179

Weight: 1 lbs 4 oz
Catalog Pages(s): 124(14),OT,26
Price: $ 47.30


Image
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
User avatar
Allan Lacki
Posts: 753
Joined: Sat Mar 13, 2010 3:06 pm

Re: Honda B20 turbo in corvair

Post by Allan Lacki »

When splitting engine from the transaxle, a good way to prevent damage to the differential snout and the input shaft is to use "guide pins". You can make them using 3/8-16 x 3" bolts. Cut off the bolt heads and slot the the ends so you can insert them with a screw driver. And then install them temporarily in place of the bellhousing bolts. That will help you to pull the transaxle straight out. They aid in re-asssembling the unit, too. I learned this trick from Davemotohead and Matt Nall on the Corvair Center Forum. See photos!
Attachments
Using guide pins to prevent snout breakage
Using guide pins to prevent snout breakage
corvair_powertrain_split_guidepins_2.jpg
User avatar
bbodie52
Corvair of the Month
Corvair of the Month
Posts: 11872
Joined: Mon Aug 06, 2012 12:33 pm
Location: Lake Chatuge Hayesville, NC
Contact:

Re: Honda B20 turbo in corvair

Post by bbodie52 »

:goodpost: :coolphotos: Great idea! The guide pins will hold things in alignment, and will permit just enough separation to reach in and pull the input shaft free of the clutch assembly! New owners who have never done this before can get into trouble if the are unaware of the potential pitfalls that lie ahead when they separate the heavy transaxle from the engine for the first time. The result can often be a broken or damaged throwout bearing shaft!

When I was a teenager my first "undocking" was done alone and unassisted, with the engine resting on some 2x4's while I bent over and straddled the transaxle, cupping the differential in my hands while backing up! Imagine my surprise and dismay when I discovered the 24" input shaft remaining firmly implanted in the clutch, as I struggled to clear it and continued backing up, hunched over with 140 lbs of transaxle between my legs!!!
:whoa: :eek: :omgosh: :workout:

I could survive such an ordeal at age sixteen... no longer!!! :oldtimer:
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
MikeDTuning
Posts: 89
Joined: Wed Jul 16, 2014 6:39 pm

Re: Honda B20 turbo in corvair

Post by MikeDTuning »

thanks for all the input! i ended up ording a the clarks reinforcemed snout, (for throw out bearing) i also found a nice video online of somebody taking apart a corvair diff, it seams like a pretty easy job.

On a different note, it also seams that i broke an input spline last night. apparently i am making pretty good power with this setup!!

i called a machine shop, it seams they can make me one for less than i originally thought. the shaft would use the 66+ gearbox, and i would have the clutch splines cut to match an OEM honda disk patturn (24 tooth) Honda Disks are very cheep, and can come in any flavor you want. These shafts would as well as compensate for a minor disk offset difference. i was told he only uses 300m grade materials, and they are "quite strong"

Bottom line, if i had more than one made to work with the honda motor, would there be any interest? i know this swap is still "new" in the corvair world, but i doubt i will be the last person.
Honda B20 turbo powered corvair. Is it the first honda powered corvair out there?
User avatar
bbodie52
Corvair of the Month
Corvair of the Month
Posts: 11872
Joined: Mon Aug 06, 2012 12:33 pm
Location: Lake Chatuge Hayesville, NC
Contact:

Re: Honda B20 turbo in corvair

Post by bbodie52 »

FOR COMPARISON...

:link: http://www.corvair.com/user-cgi/catalog ... ge=OTTO-27
Image

Part number C5476: 66-69 3 & 4 SPD INPUT SHAFT-NEW USED=CU134

Weight: 5 lbs 0 oz
Catalog Pages(s): 128,OT,27
Price: $ 229.15


The attached differential overhaul guide has numerous photographs that may also prove to be helpful...
Attachments
Rebuilding the Corvair Differential.pdf
Rebuilding the Corvair Differential
(1.21 MiB) Downloaded 115 times
Brad Bodie
Lake Chatuge, North Carolina
Image 1966 Corvair Corsa Convertible
MikeDTuning
Posts: 89
Joined: Wed Jul 16, 2014 6:39 pm

Re: Honda B20 turbo in corvair

Post by MikeDTuning »

i saw that, the v8 shafts are aroumd 350, i would expect the honda one to be around the same price
Honda B20 turbo powered corvair. Is it the first honda powered corvair out there?
notched
Posts: 674
Joined: Wed Jul 25, 2012 8:13 pm
Location: Southern New Jersey

Re: Honda B20 turbo in corvair

Post by notched »

The only 2 things I can add.......
If you are taking your differential apart I would highly recommend adding a 4 spider carrier to it. The spider gears are the Corvair differential's achilles heal. From the factory they all come with 2 spiders. Crown, Otto Parts/Clark's offered a carrier that allowed the addition of 2 more to help spread the load.
The other thing is to not use too aggressive a clutch disc as they tend to break things as well. I had this issue with a Corsa many years ago with Otto Part's 6 puck ceramic disc. I broke the main shaft (not the input) inside the 65 gear box on an aggressive 2-3 shift.
1966 Corsa turbo
1969 Monza convertible
1987 Buick Grand National
djmhwd
Posts: 10
Joined: Sun Apr 26, 2015 9:47 am

Re: Honda B20 turbo in corvair

Post by djmhwd »

How much does an engine swap like that run?
Post Reply

Return to “V8's - V6's - and...?”