High horse engines with factory A/C - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bigkountry · 06-18-2010, 03:19 PM

New to the board and have found alot of great insight and answers to many questions I have had so far..great site!

I do have one question for the guys/gals running high horse engines with the factory A/C.

I am in the process of building a 434 small block and I would like to run my factory air when it is all over and done with. Have any of you had any problems doing this? I know the fundamentals would be the same but would the higher RPM I will be spinning have any adverse effects on the A/C?

If you fall into this category, let me know any tips or tricks to get this done when the time comes. My stock compressor is shot so I will need a new one before it will all work. Only reason I want to run the A/C is my young-uns will be riding with me on occasion.

Thanks in advance.

Richard H. · 06-18-2010, 03:37 PM

Welcome here...If the clutch is not engaged it is just an idler pulley. No problems. BTW the more HP the better running AC.

bigkountry · 06-18-2010, 04:12 PM

Thanks for the info.

Most times I would yank the A/C out and toss it, but the kids need that cool air when they are with me. Plus it would be kinda cool to have it on there and functional.

junkyardjohn · 06-18-2010, 04:55 PM

IT SEEMS TO ME THE LAND SPEED RECORD WAS SET OUT AT BONNEVILLE WITH A CAR THAT HAD A VINTAGE AIR SETUP PUMPING COOL AIR. I THINK I READ THAT ON SOME VINTAGE AIR LITERATURE. (NOT TO BE CONFUSED WITH COLD HARD FACTS)

JOHN

**68 Stepside** · 06-18-2010, 08:45 PM

I have ridden in an 850HP street truck with A/C. I think he used a Sanden compressor, it can be done for sure.

PanelDeland · 06-18-2010, 09:00 PM

JYJ,Vintage Air built a Stude to run 200 MPH with the air on,I think they wrote it off as advertising and used it in their ad campaign.They did have to get a wrecker the first time out.The air worked but somehow they wound up in a wet area.

Kayotic · 06-18-2010, 11:34 PM

RPM's would be about the same so I don't think there would be any problems.

'72customdeluxe · 06-19-2010, 12:26 AM

Quote:

Originally Posted by bigkountry

Thanks for the info.

Most times I would yank the A/C out and toss it, but the kids need that cool air when they are with me. Plus it would be kinda cool to have it on there and functional.

wut?

But anyway, on some performance cars running v-belt accesories and higher rpm than standard engines, deeper than standard pullies were used to keep belts from flying off or flipping. I have had no issues with my a/c and have been up to 5500 rpm or so. I never rev it very high with the a/c on however.

pumpkin · 06-19-2010, 10:41 AM

As long as the compressor doesn't spin at high rpm for long it will be fine. I did a trip from Canada to L.A. with 4.56 gears and a th400. The engine was turning 4000 rpm the whole trip. My a/c compressor only made it a little ways back before it grenaded.

GASWAGON · 06-19-2010, 01:59 PM

The hp of the engine isn't the problem. The lack of engine vaccum to open and close the doors etc on the factory a/c box is. Most high performance engines have a camshaft with more duration which equals lower vaccum. Try it and if it doesn't work well you can always install a vaccum can.

'72customdeluxe · 06-19-2010, 02:11 PM

You can always run no vacuum and force the recirc flap open like mine. Haven't felt like replacing all the hoses

mrh33916 · 06-19-2010, 02:59 PM

Quote:

Originally Posted by Richard H.

Welcome here...If the clutch is not engaged it is just an idler pulley. No problems. BTW the more HP the better running AC.

X2

It's the best of both world's.

Run the a/c when you want to be cool.

And turn it off when it's time to get "NASTY"

That's what I do with my ZZ430 spinning a Sanden Compressor.

tonypaul · 06-19-2010, 04:57 PM

I would keep the belt on for everyday driving and if I went to the strip I would just take the belt off. Even thought its somewhat of a idler when shut off it still has a little drag to it...

bigkountry · 06-24-2010, 04:15 AM

Thanks for all the responses and insight on this, I have never had A/C on any of my toys and was just wondering.

I planned to ge either deep v-belt or March serpentine set up, just weighing out the differences in the two. I have thought about taking off the belt when I hit the strip and bypassing the compressor pulley and it is a possibility I will go that route.

My main concern is the vacuum that was mentioned...this is the cam I have in my shop and will be running---> http://www.lunatipower.com/Product.aspx?id=2326&gid=297

I have an old vacuum can from when I used to race that I coul duse if need be to trouble shoot.

It will be a while before this takes place, block is still at the shop being line bored and splayed caps put on plus I work 60+ a week so play time is minimum.

Thanks for all the help and suggestions.

78bronzechariot · 06-24-2010, 09:07 AM

Also, if you have a big cam, you may have to crank up your base idle. My 78 Caprice (My c10 doesn't have a/c) has a 375 horse 350 with a cam that is healthy enough it won't idle smooth. For it to idle in gear with the Air on, I have the base idle set at 1150. It is fuel injected so I don't have to worry about dieseling when I shut it off.

06-18-2010, 03:19 PM	#1
bigkountry Family Man Join Date: May 2010 Location: Western Kentucky Posts: 80	High horse engines with factory A/C New to the board and have found alot of great insight and answers to many questions I have had so far..great site! I do have one question for the guys/gals running high horse engines with the factory A/C. I am in the process of building a 434 small block and I would like to run my factory air when it is all over and done with. Have any of you had any problems doing this? I know the fundamentals would be the same but would the higher RPM I will be spinning have any adverse effects on the A/C? If you fall into this category, let me know any tips or tricks to get this done when the time comes. My stock compressor is shot so I will need a new one before it will all work. Only reason I want to run the A/C is my young-uns will be riding with me on occasion. Thanks in advance.

06-18-2010, 03:37 PM	#2
Richard H. Spanked once Join Date: Oct 2006 Location: Intheshop, Indiana Posts: 969	Re: High horse engines with factory A/C Welcome here...If the clutch is not engaged it is just an idler pulley. No problems. BTW the more HP the better running AC. __________________ The ole 350 budget build. Last edited by Richard H.; 06-18-2010 at 03:46 PM.

06-18-2010, 04:12 PM	#3
bigkountry Family Man Join Date: May 2010 Location: Western Kentucky Posts: 80	Re: High horse engines with factory A/C Thanks for the info. Most times I would yank the A/C out and toss it, but the kids need that cool air when they are with me. Plus it would be kinda cool to have it on there and functional.

06-18-2010, 04:55 PM	#4
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,427	Re: High horse engines with factory A/C IT SEEMS TO ME THE LAND SPEED RECORD WAS SET OUT AT BONNEVILLE WITH A CAR THAT HAD A VINTAGE AIR SETUP PUMPING COOL AIR. I THINK I READ THAT ON SOME VINTAGE AIR LITERATURE. (NOT TO BE CONFUSED WITH COLD HARD FACTS) JOHN __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST

06-18-2010, 08:45 PM	#5
68 Stepside huh? Join Date: May 2000 Location: Washington, Illinois Posts: 5,692	Re: High horse engines with factory A/C I have ridden in an 850HP street truck with A/C. I think he used a Sanden compressor, it can be done for sure. __________________ Someday when I'm lonely, Wishing you weren't so far away, Then I will remember Things we said today. RIP El Jay

06-18-2010, 09:00 PM	#6
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	Re: High horse engines with factory A/C JYJ,Vintage Air built a Stude to run 200 MPH with the air on,I think they wrote it off as advertising and used it in their ad campaign.They did have to get a wrecker the first time out.The air worked but somehow they wound up in a wet area. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"

06-18-2010, 11:34 PM	#7
Kayotic Registered User Join Date: Mar 2008 Location: Lawrenceville, Ga Posts: 300	Re: High horse engines with factory A/C RPM's would be about the same so I don't think there would be any problems. __________________ Atlanta Craigslist Hurst Indy Pickup Truck 3-Speed Shifter - 5010016

06-19-2010, 10:41 AM	#9
pumpkin Registered User Join Date: Apr 2006 Location: East Sooke B.C. Canada Posts: 543	Re: High horse engines with factory A/C As long as the compressor doesn't spin at high rpm for long it will be fine. I did a trip from Canada to L.A. with 4.56 gears and a th400. The engine was turning 4000 rpm the whole trip. My a/c compressor only made it a little ways back before it grenaded.

06-19-2010, 01:59 PM	#10
GASWAGON AMERICAN IRON ADDICT Join Date: Oct 2007 Location: MA Posts: 299	Re: High horse engines with factory A/C The hp of the engine isn't the problem. The lack of engine vaccum to open and close the doors etc on the factory a/c box is. Most high performance engines have a camshaft with more duration which equals lower vaccum. Try it and if it doesn't work well you can always install a vaccum can.

06-19-2010, 02:11 PM	#11
'72customdeluxe Registered User Join Date: Jan 2008 Location: Tejas Posts: 691	Re: High horse engines with factory A/C You can always run no vacuum and force the recirc flap open like mine. Haven't felt like replacing all the hoses __________________ '72 cheyenne super step, '05 long bed gmc

06-19-2010, 04:57 PM	#13
tonypaul Registered User Join Date: Nov 2009 Location: Austin Tx Posts: 639	Re: High horse engines with factory A/C I would keep the belt on for everyday driving and if I went to the strip I would just take the belt off. Even thought its somewhat of a idler when shut off it still has a little drag to it...

06-24-2010, 04:15 AM	#14
bigkountry Family Man Join Date: May 2010 Location: Western Kentucky Posts: 80	Re: High horse engines with factory A/C Thanks for all the responses and insight on this, I have never had A/C on any of my toys and was just wondering. I planned to ge either deep v-belt or March serpentine set up, just weighing out the differences in the two. I have thought about taking off the belt when I hit the strip and bypassing the compressor pulley and it is a possibility I will go that route. My main concern is the vacuum that was mentioned...this is the cam I have in my shop and will be running---> http://www.lunatipower.com/Product.aspx?id=2326&gid=297 I have an old vacuum can from when I used to race that I coul duse if need be to trouble shoot. It will be a while before this takes place, block is still at the shop being line bored and splayed caps put on plus I work 60+ a week so play time is minimum. Thanks for all the help and suggestions.

06-24-2010, 09:07 AM	#15
78bronzechariot Registered User Join Date: Mar 2010 Location: Red Bud, IL (Home) Newton, IL (Shop) Posts: 301	Re: High horse engines with factory A/C Also, if you have a big cam, you may have to crank up your base idle. My 78 Caprice (My c10 doesn't have a/c) has a 375 horse 350 with a cam that is healthy enough it won't idle smooth. For it to idle in gear with the Air on, I have the base idle set at 1150. It is fuel injected so I don't have to worry about dieseling when I shut it off.



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