SOT: The truth about Corvair engines, Nothing but the facts and experience, please |
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SOT: The truth about Corvair engines, Nothing but the facts and experience, please |
Tom_T |
Feb 21 2011, 06:46 PM
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#81
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TMI.... Group: Members Posts: 8,320 Joined: 19-March 09 From: Orange, CA Member No.: 10,181 Region Association: Southern California |
I installed the tranz cooler on my PG. It was probably over kill, but I figure I like to floor it over mountain passes, in a bread box, in summer so it couldnt hurt. It was hard to find info on the cooler, it is not common and no pics could be found. I had to consult a guru about how to install and such and still no one could tell me which port is in and which is out. IIRC that was an extra cost pick-up & Van heavy duty option with the auto trans (powerglide), and IIRC it had inlet higher than outlet - so you had gravity flow through the fin-box. If that's how you did yours, then it should be okay, so long as the "bread box" isn't so low it gets whacked off on the road. Is there any other way to drive either a Greenbriar or a VW Bus/Van in the hills/mountains, than to the floor!!?? (IMG:style_emoticons/default/biggrin.gif) BTW - the dealer we got it from was out by you Doc - in or near Bridgeville/Upper St. Clair Twp., but don't know if they're still there. Small world (IMG:style_emoticons/default/smile.gif) I cant remember off hand how I have it plumbed. I have the cooler in the left rear behind the wheel. It is in its own little spot and protected by a mud flap from road debris. If I hit that, something went very wrong. Thanks for the info, no one on the corvair forum could answer it. When I say that I was flooring it going over the mountains, I mean that I was doing 80mph, up hill (IMG:style_emoticons/default/wink.gif) Not that I had to do it to make it, just that I could. And that was in a pig-rich running, not quite tuned setup. I cant wait to see how it does now. Yes - VERY wrong indeed! (IMG:style_emoticons/default/laugh.gif) Mom's technique was to speed downhill in the Greenbriar to get a run for the uphill & finish it off at a decent speed. Dad called her "Lead Foot", & she called him "Lead Bottom" cuz he'd never drive over 55 mph - back when 65 was common & TX had 75 speed limits! (IMG:style_emoticons/default/biggrin.gif) I've done that technique with our 88 Westy & stock 2.1L WBX4 + Auto (wife's DD, mine on trips!), but the higher speed running apparently caused it to throw a rod at 85 mph downhill at night in the middle of the CA desert on the return leg of one of our kids & my annual XC trips to Indy, Little Rock, OK & once to Pgh. It only had about 120k then, and that got us a whole new 2.1L rebuilt motor in her - no core refund (IMG:style_emoticons/default/dry.gif) , but it was before I knew about the GoWesty up-builds. (IMG:style_emoticons/default/sad.gif) Your bus on the built up 'vair should haul booty now! (IMG:style_emoticons/default/driving.gif) |
Smitty911 |
Feb 21 2011, 08:42 PM
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#82
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Member Group: Members Posts: 294 Joined: 19-March 08 From: La Mirada, Ca Member No.: 8,830 Region Association: Southern California |
I spent some quality time at a local Corvair house in SoCal today.
Lots of good information and parts avalibility. I was even giving some instructions on how to do the whole thing, sans fab work. Looking like it do able in the sub $6,000 range. Head work is the expensive part, Deep Pocket Seats are recommended to help avoid the dropped seat issue. Lots of motors avalible and looking at the internals seem very easy to build. Of course my CDO (That's OCD for those who don't suffer from Obsessive Compulsive Disorder) would have to be kept in check from not Anodizing or polishing the Aluminum Block, Heads, etc. etc. etc. In discussing it was suggested to keep the Compression Ratio down to a pump gas level. Use a Cam for a Manual Car, Clean up the ports, Balance everything as close as possible, use new materials for gaskets and viola, AIR-914. I'm putting a budget and parts list together now, if anyone else is intrested. If a couple people want to do this we may be able to get a nice discount. No promises, but Cash talks, and BS Stinks. Smitty |
Dr Evil |
Feb 21 2011, 08:52 PM
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#83
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Send me your transmission! Group: Members Posts: 23,036 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region |
How much is the head work? Shop around to the other places that work on these, the prices vary quite a bit. If you have the heads already, Corvair Ranch may be able to beat the locals. $6000 seems high as I did my build for less than that with new VW parts, etc.
Check parts prices against Clark's catalog, then call around and see what you can get for less. Corvair Ranch does beat Clark's prices, most retailers use Clark's as a base and go up from there. |
Smitty911 |
Feb 21 2011, 08:55 PM
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#84
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Member Group: Members Posts: 294 Joined: 19-March 08 From: La Mirada, Ca Member No.: 8,830 Region Association: Southern California |
How much is the head work? Shop around to the other places that work on these, the prices vary quite a bit. If you have the heads already, Corvair Ranch may be able to beat the locals. $6000 seems high as I did my build for less than that with new VW parts, etc. Check parts prices against Clark's catalog, then call around and see what you can get for less. Corvair Ranch does beat Clark's prices, most retailers use Clark's as a base and go up from there. Dr. Evil, My mistake, I was including the cost of the SDS-EFI two additional throttle Bodies for the FI. The Motor with Mostly new parts is only around $3,000 and some change. But that's why I'm making a spread sheet (IMG:style_emoticons/default/biggrin.gif) |
jk76.914 |
Feb 21 2011, 09:07 PM
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#85
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Senior Member Group: Members Posts: 809 Joined: 12-April 05 From: Massachusetts Member No.: 3,925 Region Association: North East States |
We got a new 63 Greenbriar Van - Blue with White stripes & the vinyl houndstooth looking upholstery - which we drove to CA on old 66 (only small bits of I-40 were started then). I think it only had the base 95 hp motor & auto trans (it was ostensibly Mom's DD), but it fried the valves in TX 1/2 way there & we were stuck while the local dealer fixed it (Amarillo IIRC - I was only 10 then, so fuzzy on the details at 58.5! (IMG:style_emoticons/default/blink.gif) ). Great car, we had 6 small kids (2 - 10 yrs), 2 parents & all slept in the car on the way & every summer trip up to 67 - back from San Diego to Pittsburgh - no AC either! (IMG:style_emoticons/default/blink.gif) As kids grew, Dad added an Army Surplus stretcher across the 2 back bench seats that folded up against the wall for driving, & open for sleeping. When we grew to 4 teens, Dad moved up to a bigger rig. Then Dad got a 67 Chevy 3/4 tom pick-up with 327 ci 2 bbl auto trans & towing pkg. with a cab over camper - ahhhh - the luxury, still no AC though! Those are great memories. Which jogged mine for some more trivia- Corvair trucks had valve rotators to make them last longer (sounds like it didn't help on yours!) and they also had a transmission oil cooler on the powerglide... Valve rotators??? (IMG:style_emoticons/default/confused24.gif) I have not seen these, any pics? I installed the tranz cooler on my PG. It was probably over kill, but I figure I like to floor it over mountain passes, in a bread box, in summer so it couldnt hurt. It was hard to find info on the cooler, it is not common and no pics could be found. I had to consult a guru about how to install and such and still no one could tell me which port is in and which is out. Valve rotators- can't find a picture, but my 1971 Corvair Parts Master lists them. Part number is 3851837. Looking through the mating parts, the heads are same as in the car, as are valve springs, keepers, and shims. The valves themselves are unique to F.C. (Forward Control- the trucks), and have the note: "Must be used with rotator 3817362." That's a different number than the one listed on the next page! Anyway, the rotator replaces the cap, and is usually thicker so usually the spring is shorter or there is a deeper relief machined in the head or something, but apparently not on the Corvair. Why the valve is different? Don't know. Also, I found nice pics of the powerglide oil cooler ports in the '61 shop manual. I'll scan them tomorrow. Getting too late tonight.... |
r3dplanet |
Feb 21 2011, 09:09 PM
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#86
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Senior Member Group: Members Posts: 679 Joined: 3-September 05 From: Portland, Oregon Member No.: 4,741 Region Association: None |
I also spent the day sourcing Corvair motors. I also stopped by my machinist's shop (who owns a 911 and a 914) and spoke with him about feasibility. He said the Corvair motor rebuild kits (including pistons, jugs, etc) should run $1000-$1500. A quick call to a local Corvair outfit confirmed this, depending on the options wanted. The heads are certainly not the cheapest. Looking around the Internet, I see that some of the vendors that Dr. Evil posted here on the first page have completely re-worked heads for $1200, but I don't see why any competent machinist would have a hard time with them.
I had no problems finding donor motors, or even donor cars, in the $250-$500 range. Here's the breakdown as I see it yet: Motor from Craigslist: $300 Machinist charge to check out the block and hot tank it: $50 Rebuild kit (-minus cam, -distributor gear) $1200 Reverse cam $128 Reverse distributor gear $128 I plan to assemble the motor myself, so no labor charge here, but let's say that I bought a shop manual and a rebuild guide for $100. So far, a bit over $1900. I guess we'll need the proper fan, but I don't know much they are off the top of my head. I seem to remember that they were cheap. This leaves the heads. New heads from a Corvair specialist? $1200. Having my machinist take care of them? $200, because the new valves and guides are part of the kit. $2100 so far. Then there's the transmission adapter and custom flywheel for $400. What's left? Fabbing an engine mount, which is extremely cheap for me because I'm handy with a torch and square tubing. So $2500 for most everything? I'm sure that I'll need to deal with a fuel pump and perhaps go with a nice distributor, but some of the engine kits include new/rebuilt distributors. Am I missing something terrible? Why the $6000? -marcus |
Dr Evil |
Feb 21 2011, 09:24 PM
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#87
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Send me your transmission! Group: Members Posts: 23,036 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region |
Marcus, that is the price point that I am more familiar with. You can get rebuilds kits for even cheaper if you use used piston/cylinders. For the head rebuild, yes a good machinist can do it, there are some points to know, though. Crush, staking, depth are specifics that need to be known.
I got an engine, several 901 transmission, a turbo setup, adapter for 901, reverse gear all for $250 on Craigs list. In CA there were many deals. The whole car often cost less than just the engine. You can usually find everything used for less on ebay and such. Cam Dizzy gear Pistons Crank Block Heads When I had all the machine work done on my first 3.1 and sold it right before med school, unassembled, I got $1700 on ebay. That was EVERYTHING for a long block. |
Dr Evil |
Feb 21 2011, 09:26 PM
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#88
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Send me your transmission! Group: Members Posts: 23,036 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region |
We got a new 63 Greenbriar Van - Blue with White stripes & the vinyl houndstooth looking upholstery - which we drove to CA on old 66 (only small bits of I-40 were started then). I think it only had the base 95 hp motor & auto trans (it was ostensibly Mom's DD), but it fried the valves in TX 1/2 way there & we were stuck while the local dealer fixed it (Amarillo IIRC - I was only 10 then, so fuzzy on the details at 58.5! (IMG:style_emoticons/default/blink.gif) ). Great car, we had 6 small kids (2 - 10 yrs), 2 parents & all slept in the car on the way & every summer trip up to 67 - back from San Diego to Pittsburgh - no AC either! (IMG:style_emoticons/default/blink.gif) As kids grew, Dad added an Army Surplus stretcher across the 2 back bench seats that folded up against the wall for driving, & open for sleeping. When we grew to 4 teens, Dad moved up to a bigger rig. Then Dad got a 67 Chevy 3/4 tom pick-up with 327 ci 2 bbl auto trans & towing pkg. with a cab over camper - ahhhh - the luxury, still no AC though! Those are great memories. Which jogged mine for some more trivia- Corvair trucks had valve rotators to make them last longer (sounds like it didn't help on yours!) and they also had a transmission oil cooler on the powerglide... Valve rotators??? (IMG:style_emoticons/default/confused24.gif) I have not seen these, any pics? I installed the tranz cooler on my PG. It was probably over kill, but I figure I like to floor it over mountain passes, in a bread box, in summer so it couldnt hurt. It was hard to find info on the cooler, it is not common and no pics could be found. I had to consult a guru about how to install and such and still no one could tell me which port is in and which is out. Valve rotators- can't find a picture, but my 1971 Corvair Parts Master lists them. Part number is 3851837. Looking through the mating parts, the heads are same as in the car, as are valve springs, keepers, and shims. The valves themselves are unique to F.C. (Forward Control- the trucks), and have the note: "Must be used with rotator 3817362." That's a different number than the one listed on the next page! Anyway, the rotator replaces the cap, and is usually thicker so usually the spring is shorter or there is a deeper relief machined in the head or something, but apparently not on the Corvair. Why the valve is different? Don't know. Also, I found nice pics of the powerglide oil cooler ports in the '61 shop manual. I'll scan them tomorrow. Getting too late tonight.... Great info, Jim. Thanks! I look forward to the pics. |
r3dplanet |
Feb 21 2011, 09:55 PM
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#89
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Senior Member Group: Members Posts: 679 Joined: 3-September 05 From: Portland, Oregon Member No.: 4,741 Region Association: None |
One more thing.
Under the heading of "interesting statistics," I found on www.corvair.org that of the 1.7 million Corvairs produced, 1.3 million of them were manufactured from 1960-1964. From 1965-1969, there were 400,000 produced, the bulk of which were born in 1965. Only 6000 were made in 1969. So while it is more difficult to get a 1965-later engine, they're going to be considerably more rare. I think that the 1964 motor, the serious transition year, would also be a good find. It doesn't have quite as meaty material where the head meets the block and the crank hasn't been chemically nitrided, but you can nitride any crank for $50 the last time I looked. The 1964 motor is still 164ci. What you need to make sure of that if you're out sourcing parts and you're buying rebuild kits, make sure that all the manufacturing years line up. 1964 is also a transition year because the later 1964 engines were actually the 1965 engines, but the 1964 engines still had the early style numbering scheme, so it might be pretty difficult to recognize a '64 motor just by the serial number. I'm posting this to others who might be snooping out engines and may find this information useful. -marcus |
Rand |
Feb 21 2011, 10:28 PM
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#90
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Cross Member Group: Members Posts: 7,409 Joined: 8-February 05 From: OR Member No.: 3,573 Region Association: None |
I understand the internals would be spinning opposite of their designed intent. But just as a mental exercise: If you install a 911 transmission in a 914 (type 4, etc) you get 5 'reverse' gears. If you then install a Corvair motor and spin that transmission backwards, don't you get 5 'forward' gears? It's still running on the 'backs' of the gears, but wouldn't flipping the diff be counter productive? I shouldn't post because I'm talking out my ass. Pfffphbbrfft. But another mental exercise: In both the 914 and 911, the main gear stack is rotating the same direction. The flipped diff is the diff(erence). So a 911 tranny in a 914 still has the main stack going the correct direction... Just the diff backwards. Spin the whole thing backwards and that makes up for the diff diff, but the core stack is now backwards. So yeah, Corvair motor plus 911 tranny = 5 gears forward and 1 reverse... But after all of this shell game, the core stack is backwards... Which is said to be bad? If two wrongs makes a right, does a wrong plus a wrong plus a right make everything wrong but actually right because it is anti counter productive? (IMG:style_emoticons/default/blink.gif) This will make more sense after I have a beer. |
ChrisFoley |
Feb 21 2011, 10:36 PM
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#91
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I am Tangerine Racing Group: Members Posts: 7,975 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
You are focusing on the OUTPUT only. The helical cut gears would be spun so that their coasting side would then be the power-on side. Not good. People (including me) set up close ratio boxes by installing gear sets in the "wrong" position all the time so that they run backwards. Yes, I know the thrust is in the wrong direction but I've never heard of any problems resulting from this. Whats the difference if all 5 gears are spinning the "wrong" direction? |
KELTY360 |
Feb 22 2011, 01:12 AM
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#92
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914 Neferati Group: Members Posts: 5,102 Joined: 31-December 05 From: Pt. Townsend, WA Member No.: 5,344 Region Association: Pacific Northwest |
I understand the internals would be spinning opposite of their designed intent. But just as a mental exercise: If you install a 911 transmission in a 914 (type 4, etc) you get 5 'reverse' gears. If you then install a Corvair motor and spin that transmission backwards, don't you get 5 'forward' gears? It's still running on the 'backs' of the gears, but wouldn't flipping the diff be counter productive? I shouldn't post because I'm talking out my ass. Pfffphbbrfft. But another mental exercise: In both the 914 and 911, the main gear stack is rotating the same direction. The flipped diff is the diff(erence). So a 911 tranny in a 914 still has the main stack going the correct direction... Just the diff backwards. Spin the whole thing backwards and that makes up for the diff diff, but the core stack is now backwards. So yeah, Corvair motor plus 911 tranny = 5 gears forward and 1 reverse... But after all of this shell game, the core stack is backwards... Which is said to be bad? If two wrongs makes a right, does a wrong plus a wrong plus a right make everything wrong but actually right because it is anti counter productive? (IMG:style_emoticons/default/blink.gif) This will make more sense after I have a beer. It makes sense if you don't think about it. |
messix |
Feb 22 2011, 01:33 AM
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#93
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AKA "CLUTCH KILLER"! Group: Members Posts: 6,995 Joined: 14-April 05 From: between shit kickers and pinky lifters/ puget sound wa.north of Seattle south of Canada Member No.: 3,931 Region Association: Pacific Northwest |
I understand the internals would be spinning opposite of their designed intent. But just as a mental exercise: If you install a 911 transmission in a 914 (type 4, etc) you get 5 'reverse' gears. If you then install a Corvair motor and spin that transmission backwards, don't you get 5 'forward' gears? It's still running on the 'backs' of the gears, but wouldn't flipping the diff be counter productive? I shouldn't post because I'm talking out my ass. Pfffphbbrfft. But another mental exercise: In both the 914 and 911, the main gear stack is rotating the same direction. The flipped diff is the diff(erence). So a 911 tranny in a 914 still has the main stack going the correct direction... Just the diff backwards. Spin the whole thing backwards and that makes up for the diff diff, but the core stack is now backwards. So yeah, Corvair motor plus 911 tranny = 5 gears forward and 1 reverse... But after all of this shell game, the core stack is backwards... Which is said to be bad? If two wrongs makes a right, does a wrong plus a wrong plus a right make everything wrong but actually right because it is anti counter productive? (IMG:style_emoticons/default/blink.gif) This will make more sense after I have a beer. stock starter would be a problem! it will still turn "the proper" direction.... |
Dr Evil |
Feb 22 2011, 07:36 AM
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#94
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Send me your transmission! Group: Members Posts: 23,036 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region |
You are focusing on the OUTPUT only. The helical cut gears would be spun so that their coasting side would then be the power-on side. Not good. People (including me) set up close ratio boxes by installing gear sets in the "wrong" position all the time so that they run backwards. Yes, I know the thrust is in the wrong direction but I've never heard of any problems resulting from this. Whats the difference if all 5 gears are spinning the "wrong" direction? It mainly is an issue with the pinion/diff. I, too, flip gears for ratios often and that is not a problem, but if the diff/pinion is not turning in the correct orientation it would not be a pretty site. Also, you dont flip 1st. 1st gear is set up to only be down shifted into whilst turning in one direction due to its band and block configuration. Shifting from reverse to 1st real fast is one way you can try what it would be like to shift into first with the box being turned the wrong way. With first running backwards, you would be prone to popping out of gear as the band would not be reinforced by the internal mechanisms of the synchronization package. |
Rand |
Feb 22 2011, 10:17 AM
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#95
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Cross Member Group: Members Posts: 7,409 Joined: 8-February 05 From: OR Member No.: 3,573 Region Association: None |
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ChrisFoley |
Feb 22 2011, 12:03 PM
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#96
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I am Tangerine Racing Group: Members Posts: 7,975 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
I'm not convinced that running the R/P backwards would hurt it.
Reversing the brake band/block on first is easy, no need to even disassemble the gearbox. I don't know if how the bearings are retained in the case would be a problem though, but the starter appears to be a significant issue. |
pt_700 |
Feb 22 2011, 01:14 PM
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#97
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Senior Member Group: Members Posts: 1,104 Joined: 4-March 10 From: san jose, ca Member No.: 11,430 Region Association: Northern California |
wish i'd known about this before buying all the kit pieces to convert to sbc.
this is a relatively minor concern but, what kind of fuel economy can be had from corvair motors? paul |
andys |
Feb 22 2011, 02:53 PM
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#98
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Advanced Member Group: Members Posts: 2,165 Joined: 21-May 03 From: Valencia, CA Member No.: 721 Region Association: None |
Interseting read, this thread is. Was cleaning out my bookshelf just last month and threw out a copy of HP Books "How to Hot Rod the Corvair." Would have gladly donated it had I known.
'66 Corsa was fast. Easiest mod was to wrap the exhaust to get more boost. There was also a 2bbl down draft carb manifold (Crown?) that used a 2G Rochester if I remember correctly. Ran 126MPH (standing start mile) at El Mirage at a time when 911's would struggle to break 100MPH. Andys |
Dr Evil |
Feb 22 2011, 05:59 PM
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#99
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Send me your transmission! Group: Members Posts: 23,036 Joined: 21-November 03 From: Loveland, OH 45140 Member No.: 1,372 Region Association: MidAtlantic Region |
If anyone is interested, I have a holley carb adapter with an almost new 390 Holley for sale. I had CIS for this engine and just decided to go that way. (IMG:style_emoticons/default/idea.gif)
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ClayPerrine |
Feb 23 2011, 05:29 PM
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#100
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Life's been good to me so far..... Group: Admin Posts: 15,983 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille |
I'm not convinced that running the R/P backwards would hurt it. Reversing the brake band/block on first is easy, no need to even disassemble the gearbox. I don't know if how the bearings are retained in the case would be a problem though, but the starter appears to be a significant issue. You also have to consider the thrust loads on both the input and pinion shafts of the 901. Turning in the correct direction, the helical cut gears on the shafts push the input and output shafts in different directions. When you reverse the input rotation, you change the thrust load. That makes the thrust bearings engineered into the transmission irrevelant, and the thrust load happens against surfaces not designed to handle it. It also changes the backlash on the ring and pinion combo. When there is load on the pinion gear, it climbs the ring gear slightly. When you reverse it, it will not climb the ring gear, changing the backlash and affecting both the life of, and the noise from the gearbox. Yes, it would work. But no, it won't last long. The extra horsepower of the corvair engine, combined with the incorrect thrust loads will make quick work of the transmission. FYI.. the reason the corvair engine turns backwards is that the corvair gearbox was a modified saginaw 4 speed that had a hollow main shaft so they could put an extra long input shaft through it's middle to connect it to the rear mounted engine. And the differental assembly is a standard 10 bolt diff that was found in everything GM made. So they made the engine turn backwards so they didn't have to make all new gearbox pieces. |
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