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Re: Kelmark V8 Engine Build Questions
Posted by: MikeBuongiorno ()
Date: January 16, 2013 12:52AM

so Ive learned that the lsx motor mounts dont need to be changed, and neither does the mounting to the kelmark adaptor. Might be going modern aferall. Anyone else done this? gotchas?

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Re: Kelmark V8 Engine Build Questions
Posted by: 66vairman ()
Date: January 16, 2013 09:23AM

A fellow I know has a really nice hi-performance 283c.i. Crown. Goes fast, very reliable. The sound at 7,000RPM is wonderful.

We've talked about the issues with too much torque from the 350c.i. engine and came up with an alternative.

A nice modern alternative is a 1969 type Z/28 302c.i. Basically a 350 block with a short stroke crank. Parts available from aftermarket folks to make one. Just use a 4 bolt main 350 block.

The 307c.i. is not efficient and basically a narrow bore, long stroke, engine. Too much low end torque, will not rev. Not what you want. They were designed to be low rev grunt engines during the smog era.

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Re: Kelmark V8 Engine Build Questions
Posted by: gnvair ()
Date: January 16, 2013 10:46AM

66vairman Wrote:
-------------------------------------------------------
> A fellow I know has a really nice hi-performance
> 283c.i. Crown. Goes fast, very reliable. The sound
> at 7,000RPM is wonderful.
>
> We've talked about the issues with too much torque
> from the 350c.i. engine and came up with an
> alternative.
>
> A nice modern alternative is a 1969 type Z/28
> 302c.i. Basically a 350 block with a short stroke
> crank. Parts available from aftermarket folks to
> make one. Just use a 4 bolt main 350 block.
>
> The 307c.i. is not efficient and basically a
> narrow bore, long stroke, engine. Too much low end
> torque, will not rev. Not what you want. They were
> designed to be low rev grunt engines during the
> smog era.

The problem with that is finding a large journal 3" stroke crank.
Its much easier to build a 302 with a small journal 327 block as you can do what Vince Piggins did to create the original; just use a small journal 283 crank.
All 350 blocks are large journal (technician medium if you take into consideration the large 400 mains). The only large journal 3" stroke cranks produced were for the factory made 302. Have you priced one lately?
Edit....Eagle has them. Prices start at $700 and go up from there.
Scat has them listed, but their prices are even higher.
The original poster still would have to gather pieces which he stated he didnt want to do.



Edited 1 time(s). Last edit at 01/16/2013 10:53AM by gnvair.

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Re: Kelmark V8 Engine Build Questions
Posted by: tkalp ()
Date: January 16, 2013 11:18AM

I have a hopped up 283 in my Kelmark converted Corvair and it seems to be a great combination. The lower torque and higher RPM power band are easier on the transaxle and work better with the low 1st gear in the Corvair 4-speed. It was built to cruise at 3000-3500 RPM all day.

It is not the fastest car on the street, but is very peppy and fun to drive. One of the smaller LS engines would be tempting, but I would think that a 3.08 final drive would be required and maybe a cam change. The LS was designed to cruise at 2000-2500 rpm with a 4 speed auto or 6 speed manual transmission. Not sure how well matched it would be to the Corvair transaxle ratios.

Whatever you chose I am sure you will find a V-8 or V-6 mid engined Corvair will draw a lot of attention and be fun to drive.

T. Kalp
Wichita, KS

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Re: Kelmark V8 Engine Build Questions
Posted by: lgoodwin ()
Date: January 16, 2013 01:11PM

+1 on the 4.3 V-6. They sound great, make plenty of power to push a Corvair, and get good gas mileage to boot! You'll also have more room in the cabin. Dare to be different, LOL.

Hey, Ed, how about posting some pictures of your 4.3 powered vair here for inspiration??? smiling bouncing smiley

<table align='center' width='0'>
<tr>
<td><img src='[www.automation-scs.com]; alt='1962 Corvair 900 sedan' width='190' /></td>
<td><img src='[corvaircenter.com]; alt='1967 Corvair Monza 140/4-speed' width='190' /></td>
<td><img src='[corvaircenter.com]; alt='1968 Corvair 500 coupe' width='190' /></td>
<td><img src='[www.automation-scs.com]; alt='1983 Mexican Mustang 5.0' width='190' /></td>
<td><a href='[www.automation-scs.com&]; target='_blank'></a></td>
</tr>
<tr>
<td align='center'><font size='1'>1962 900 sedan needs a home</font></td>
<td align='center'><font size='1'>1967 Monza 140/4-spd</font></td>
<td align='center'><font size='1'>1968 500 coupe (now my son's)</font></td>
<td align='center'><font size='1'>1983 Mexican Mustang 5.0</font></td>
</tr>
</table>

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Re: Kelmark V8 Engine Build Questions
Posted by: v8vair ()
Date: January 16, 2013 01:25PM

The problem IMHO with the small motor is you end up running the hell out of it trying to get it to go.
I never had a transaxle failure on the street,327 Crown, 400 crown,283 Crown and the last,my current race car had a 450hp 383.
Drive it like a sports car,not a 396 Chevelle and pay attention to detail(often overlooked on a Crown)
Two ring and pinion failures on the race track but that was with a 540 hp 406 and the Ring and pinions that failed should of been cycled out of service sooner. Mike

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Re: Kelmark V8 Engine Build Questions
Posted by: gnvair ()
Date: January 16, 2013 04:28PM

v8vair Wrote:
-------------------------------------------------------
> The problem IMHO with the small motor is you end
> up running the hell out of it trying to get it to
> go.
> I never had a transaxle failure on the street,327
> Crown, 400 crown,283 Crown and the last,my current
> race car had a 450hp 383.
> Drive it like a sports car,not a 396 Chevelle and
> pay attention to detail(often overlooked on a
> Crown)
> Two ring and pinion failures on the race track but
> that was with a 540 hp 406 and the Ring and
> pinions that failed should of been cycled out of
> service sooner. Mike

You arent running the gears in the gear box or the ring and pinion backwards (on the coast side) in your Crown like the poster is with his Kelmark. Your Crown also uses a conventional input gear and not a 2 foot long input shaft driving the stock Corvair input gear. Those are the caveats with the Kelmark conversions and why they are not recommended for high power.



Edited 1 time(s). Last edit at 01/16/2013 04:30PM by gnvair.

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Re: Kelmark V8 Engine Build Questions
Posted by: v8vair ()
Date: January 16, 2013 04:57PM

Like I said, the small motors tend to make you abuse them more.
And the kelmarks seem too break often,save your money if you want the leg room and use a Porsche transaxle. Just my opinion from what I have seen over the last 35 years of building V8 vairs. Mike

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Re: Kelmark V8 Engine Build Questions
Posted by: ManxManiac ()
Date: January 16, 2013 06:04PM

Back in the 70s, my 66 Crown had a Chevy Z/28 302 cid/500hp engine w/4.11 R&P. That particular "mouse motor" would turn 8500+ rpms real easy. Since I "drove it like I stole it" ALL OF THE TIME, some folks accused me of abusing it, but I never broke anything. It sure sounded sweet humming along at high rpms! gggg

The last Chevy 302 cid I built about 10 years ago, I picked up a 1972 350 4 bolt main block that was in excellent condition & didn't need to be bored for $150.00. Then I bought a new GM 3" stroke large mains crankshaft for $400.00. The total parts for it (running) were a hair over $2500.00. Of course I wheeled & dealed for a lot of the parts too. A friend dyno'd it for free, 430hp at the "flywheel". The one in my Crown had quite a bit of head work.

You can always try to find a 283 or 307 block same thing, (307 is 283 block w/327 crank) that has "0" or very minimal core shift & you should be able to bore it .120" over, which makes it 301 cid. Then using a stock 3" stroke 283 cid crankshaft you're real close. Run a extra large aluminum radiator & an aluminum water pump & it should keep nice & cool. I've built at least 10 of these over the years & even after being constantly run hard, never had any problems with any of them.

Seems I remember some heat-treating trick guys did to the R&P in a Kelmark setup that helped them survive a lot longer. Anyone remember exactly what it was???

Good Luck on whatever engine you go with, just get it done so you can start having FUN FUN FUN!!!


Have Fun, Fun, Fun... ManxManiac

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Re: Kelmark V8 Engine Build Questions
Posted by: 66vairman ()
Date: January 16, 2013 07:16PM

Thanks for the counter point on the 302 Phil.

Manx - I can't remember the owner’s name, but he had a very nice Kelmark at the GWFBT years ago. One thing he did to enhance the ring and pinion was to install an oil pump to cycle differential oil to the ring and pinion contact area. The owner claimed it worked well.

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Re: Kelmark V8 Engine Build Questions
Posted by: MattNall ()
Date: January 16, 2013 07:19PM

66vairman Wrote:
-------------------------------------------------------
> Thanks for the counter point on the 302 Phil.
>
> Manx - I can't remember the owner’s name, but he
> had a very nice Kelmark at the GWFBT years ago.
> One thing he did to enhance the ring and pinion
> was to install an oil pump to cycle differential
> oil to the ring and pinion contact area. The owner
> claimed it worked well.
=========================================================

But he is only running a 215 iirc... 20 years.. no failure...but no idea of miles..

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Re: Kelmark V8 Engine Build Questions
Posted by: gnvair ()
Date: January 16, 2013 07:27PM

I seem to remember someone had Richmond make a reverse ring and pinion years ago but finding a set might be like finding the proverbial needle in a hay stack.

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Re: Kelmark V8 Engine Build Questions
Posted by: MattNall ()
Date: January 16, 2013 07:31PM

gnvair Wrote:
-------------------------------------------------------
> I seem to remember someone had Richmond make a
> reverse ring and pinion years ago but finding a
> set might be like finding the proverbial needle in
> a hay stack.
============================================================

Correct.. just like the 1/2 dozen GM made for it's showcars that used a mid Vair..


Sadly the "majority" of those Rev. R&P's were not heat treated correctly....

And most didn't find out before the failure... Richmond re-treated all who sent them in...

That's what I've seen written on the Web... must be true!! gg

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Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Kelmark V8 Engine Build Questions
Posted by: MikeBuongiorno ()
Date: January 16, 2013 10:11PM

All great stuff.

My car is setup with the oiler on top of the diff lubricating the reverse spinning ring gear. I'm most worried about the shaft from what Ive read.

4.8 Gen III is an aluminium engine. Lighter car, less broken parts right? Anything else that can be done to lighten the shock load? 12" clutch with heavy springs? Heavy flywheel/balancer?

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Re: Kelmark V8 Engine Build Questions
Posted by: MattNall ()
Date: January 16, 2013 10:12PM

Narrow % short rear tires

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: Kelmark V8 Engine Build Questions
Posted by: MikeBuongiorno ()
Date: January 16, 2013 11:54PM

With your help, I think I found the ideal power plant.

4800 Vortec LM4 Gen 3 aluminium block and all, 290hp, 300 ftlbs. Probably buy a donor car and do the computer and everything. Will keep up the research and keep you posted. Thanks team!!

-Mike

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Re: Rear engine V6
Posted by: Ed Dowds ()
Date: January 17, 2013 04:54AM

Lgoodwin wrote:

"Hey, Ed, how about posting some pictures of your 4.3 powered vair here for inspiration???"

Here are some build pictures:

Ed
Hamilton, NJ
66 500 rear 4.3 V6 Corvair
69 350/350 TH Camaro was RS
30 Model A Ford Streetrod 350/400 TH
88 Celebrity Wagon (Daily Driver)



Edited 1 time(s). Last edit at 01/17/2013 04:55AM by Ed Dowds.

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Re: Kelmark V8 Engine Build Questions
Date: January 17, 2013 10:13AM

Not hard to build a 302. HR mag did it with a LT1 a few years back.. Get the crank from the small V8 put into mid 90's caprices. (4.3 V8) and use the rest from an LT1 of the same Gen (5.7).

Keep in mind that while the aluminum head cars (fbody and vette) are lighter motors, the impalas, 9C1's and roadmasters iron heads actually flow more. The only 4 bolt blocks came in the vettes, but probably overkill for a street car. LT's are getting dirt cheap, made a lot of power and were reliable once you vented the opti spark. I loved our Caprice wagon, even before we did any major engine work it would run 14.6's in a 4400# wagon, nothing more then 3.55's, intake and a tune.

The LT gives you a nice upgrade from older style small blocks while not being as hard to adapt an an LS engine. + it's cheap.

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Re: Kelmark V8 Engine Build Questions
Posted by: MikeBuongiorno ()
Date: January 20, 2013 11:24AM

Hit a (major?) snag.

The gen 3 requires as far as I am reading a 14 1/8" 168 tooth flywheel.

My kelmark special adapter for SBC to corvair diff is 14." Plus the gen 3 pushes the flywheel into the bellhousing / adapater 0.4" deeper. Looks like I need to scrap the gen 3 plan, or mill out my adapter (if even possible) or cast / fab a new adapater (not gonna happen).

Anyone know of a work around I might not yet have read about?

most of my info is from this very nice car craft article on using gen 3 and classic trans (my config is the corvair diff and saginaw 4 speed).

[www.carcraft.com]


-mike

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Re: Kelmark V8 Engine Build Questions
Posted by: MikeBuongiorno ()
Date: September 06, 2013 10:20PM

Update

Spent some money, did some work, getting it close to plugging it back in.

$750 5.3L aluminum block/heads LSx motor from www.car-part.com 70k miles from a 2001 Envoy, $350 LS1 intake, cam from ebay (both reduce torque / increase hp over stock truck setup). $200 low profile oil pan and other bits. On paper should be around 350/350 torque and hp.

Milled the kelmark adapter to accommodate massive third gen flywheel and starter. I think I have all my spacing worked out, we'll see. Going to try to mate everything up this weekend.

After that, plumb the high pressure fuel line and sort a harness / computer/ gauges...And all the small stuff that takes longer than we ever anticipate.

Couple questions:
-I read here that '66+ tranny and diff are stronger than 65? Why, and how would I identify what I have? 6 bolts vs 4? Going to investigate waht I have this weekend. Sure hope its four spider, otherwise realize I'll need to do that. With the car I got an extra diff and two extra four speeds. Feels like G50 porsche axle is the way to go, but I really dont have or want to wait to save $5k when I've got the parts I have, and plan on driving a sports car, not a dragster (I have SOME self control, I hope!)
-Motor and adapter are on the stand, diff and tranny are in the car. Is it feasible to install the motor straight away, or is it typical to pull everything, build the driveline end to end, then slide it in? Wondering how tricky it is going to be to get the input shaft sorted while trying to align and seat the engine mounts.

Thanks! and will get some pics up sunday evening. Vairking, thanks for the vote of confidence!

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