Corvair DiagramCorvair Photo
Corvair Center
home forum corvairs calendar links Corvair Podcast
California Corvairs
Clarks Corvair
Clarks Corvair
“CORSA"



Chevy Corvair License Plate
Chevy Corvair Chrome Wheel
Corvair Center Forum :  Corvair Center Phorum The fastest message board... ever.
Corvair Center 
Current Page: 2 of 4
Re: Engine runs strong but no boost.
Posted by: Frank DuVal ()
Date: September 22, 2019 09:42AM

On a Carter YF, the downdraft equivalent to the side draft YH, there is an idle tube (idle air bleed) that can get clogged and cause flooding. Make sure all the passages are clear.

Frank DuVal

Fredericksburg, VA

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: DOUG WARD ()
Date: September 22, 2019 05:24PM

OK Matt, I finally did what you suggested & pinched off the fuel supply hose until the dripping stopped. By loosening it up just a tiny bit, it began to flood again & the fuel was running out of the carb again. BTW, I also took out the spring loaded float valve & changed it to a solid brass one. That seemed to help seal the flow a little bit but it did still drip. Now that I have results with reducing the flow, what do you recommend ? A regulator ? Seems like a fuel pressure gauge would only tell me what I already know, that there is too much fuel pressure. Where do I get a regulator,& where / how is it mounted ? Doug Ward

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: AlecCarlson ()
Date: September 22, 2019 05:36PM

I have an electric fuel pump and use a Holley 12-804 fuel pressure regulator. The Carter likes low pressure fuel - about 2 PSI. It is mounted on the output side of the fuel filter.

Alec



Edited 1 time(s). Last edit at 09/22/2019 05:37PM by AlecCarlson.

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: playerpage ()
Date: September 23, 2019 12:40AM

I use a Holly 804 too. Here's where I got mine.

Summit Racing

The pictures show a close up of the installation and a perspective of where it is on the car.

____________________________________________

Eric C. Player, Porterville, CA
Member: CORSA National, Central Coast CORSA, South Coast CORSA, and San Joaquin Valley Corvair Club
THEN: 1965 Monza 110 Canary Yellow
1967 Monza 140 Red
1966 500 110, Black; nicknamed "Shadow"
1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo; nicknamed "Bluvair"

"It would not have helped if I had [taken notes], as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

------

Attachments:

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: JimBrandberg ()
Date: September 23, 2019 05:16AM

I hard plumbed a Holley regulator like the one pictured from the stock fuel filter to a Weber. It's hard to find just one fitting to make some of the conversions. I seem to remember the regulator being 3/8 NPT.
Plumbing it with rubber hose for testing is probably okay but long term not so much. You can get by with lesser installations on your own car.

I've seen Corvair mechanical fuel pumps putting out 9#s of pressure which easily overcomes the inlet needle and seat.

I think you're probably on the right track with the excessive fuel pressure thing.

When checking the needle or ball checks you verified that your rubber bladder is in good condition?

I like the Mike's Carburetor Parts video.

Jim Brandberg
Isanti, MN
CorvairRepair.com



Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: AlecCarlson ()
Date: September 23, 2019 11:02AM

Here is my Corsa engine with Holley pressure regulator installed:

Attachments:

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: thewolfe ()
Date: September 23, 2019 12:19PM

A bit of advice for Eric. Looking at how your regulator is mounted, it appears the line at the bottom is taut. Or maybe it's the angle of the picture but you need some slack in that line because when you go around corners, the engine shifts relative to the body of the car and the line will be getting tugged on since the regulator is mounted to the body.

Nate Wolfe
Portland OR
65 Corsa 180

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: playerpage ()
Date: September 23, 2019 01:42PM

Thanks Nate.

It's a little more slack than it looks but that is definitely something to consider. I can't go out to the car to take a picture of it right now, and maybe I'll forget and never do it, but there is a new line running from the Holley to the back of the YH carburetor that isn't shown and is a little more substantial.

____________________________________________

Eric C. Player, Porterville, CA
Member: CORSA National, Central Coast CORSA, South Coast CORSA, and San Joaquin Valley Corvair Club
THEN: 1965 Monza 110 Canary Yellow
1967 Monza 140 Red
1966 500 110, Black; nicknamed "Shadow"
1965 Monza 110, Camaro Yellow; nicknamed "Silver"
NOW: 1966 Corsa 180 Turbo; nicknamed "Bluvair"

"It would not have helped if I had [taken notes], as he would start a paragraph with, 'It is therefore obvious. . .'
and go on from there to matters which may have been obvious to him and God but to no one else."
-- Robert A. Heinlein, character of Daniel B. Davis, 'The Door Into Summer.'

------

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: thewolfe ()
Date: September 23, 2019 02:03PM

I'm talking about the one going into the shroud and connected to the bottom of the regulator. I have a similar setup and had a line with no slack there as well. One time when I jacked that back corner of the car up I saw how much that line was being stretched, ready to pull right off the bottom of the regulator. That line promptly got replaced with one that had several inches of slack. The engine shrouds move around relative to the body when you are cornering.

Nate Wolfe
Portland OR
65 Corsa 180

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: playerpage ()
Date: September 23, 2019 03:54PM

Check. thumbs up

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: DOUG WARD ()
Date: September 24, 2019 08:53PM

Here's the latest update on my flooding situation, guys. Thanks to some of your posts and pictures, I have been made aware of a couple of good points; Hard plumbing id better than hoses. Don't mount the regulator on the firewall; especially if it's hard plumbed. I'll mount my regulator to the back side of the air cleaner, & hard plumb it. That way, it will move around with the engine & not stress the rigid plumbing . I have had quite a time in getting my parts ( Holley regulator P/N 12 - 804, 1 to 4 psi range & Holley P/N 26 - 500 gauge ). I couldn't reach Holley on the phone ( number disconnected ) & Summit can not ship the regulator to California. I found both Holley products on the shelf at O'Reilly's auto parts store. in Garden Grove, Ca. Their price for the regulator was a little less than Summit's but the gauge was $36.00 and they price matched Sunmits at $ 22.00. I am still looking for the correct fittings to put this stuff together so I don't have any performance info for you yet. Stand bye. Doug Ward

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: DOUG WARD ()
Date: September 27, 2019 08:58PM

Here is what I did . Installed the new Holley fuel pressure regulator & 0 - 15 PSI gauge. It came out of the box, adjusted @ 2 PSI, which is what I had hoped to set it at to try & control the YH flooding problem. It still floods. I haven't been able to drive it enough to see if the MPG has improved. I feel that, so far, it's still about 9 MPG.
Next, I'll try to optimize the main jet and pump rod sizes. I wouldn't be surprised if I find the jet to be too large. It's a # 257. measured hole size is .077".( book spec says it should be .098") metering rod is P/N 75-1716 & it's diameter is .070, stepped down to .045"( the book spec says it should be .057, stepped down to .048 This is a little confusing but I'll get to the bottom of the problem somehow.
Also, I don't think the rod even gets down into the jet to even reach the step, given the amount of travel it has. I don't have a gauge to set the pump height & maybe that is the problem.
I know I ramble on a bit, but if you guys can say anything that i"m missing, please let me know. Doug Ward

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: MattNall ()
Date: September 27, 2019 09:14PM

Myself... I'd send the carb to Steve C Goodman.... ask him to inspect.... and fix anything he finds wrong..

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

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: Frank DuVal ()
Date: September 27, 2019 09:16PM

Sit back and think, then answer this question:

When you first got the car, did it flood and only get 9 MPG?

Quote

It's a # 257. measured hole size is .077".( book spec says it should be .098")

If the hole size is already smaller than stock, then how would putting a larger jet in fix flooding? Or am I missing something?confused smiley

Frank DuVal

Fredericksburg, VA

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: DOUG WARD ()
Date: September 28, 2019 12:23AM

Frank, My comment about jet size was mainly directed to fuel economy. But a good observation anyway. Thanks. The MPG has never been good.
Matt, can you give me some contact info for Steve Goodman ? Thanks.
BTW, guys, I'm still not getting any boost. I've tested the gauge & it's responsive to a 20 PSI shot of air pressure from the head connection.
Do you guys think the carb problems have anything to do with the lack of boost ? The engine is strong & revs up well. Or do I have a turbo problem too ? I think the exhaust system is in pretty good condition. No obvious leaks, stock muffler.
The car had the original pressure only retard on the distributor, seemed to be OK. I have since installed a combination pressure retard / vacuum advance & didn't notice any performance difference. Timing is set @ 24 degrees with the vacuum hose pinched off.
Doug Ward

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: JimBrandberg ()
Date: September 28, 2019 06:29AM

Doug Ward wrote:

" It still floods."

----------------------------------------------------------------------------

If that's the case you need to get that resolved before anything else.

Have you messed around with the float level? How does the fuel level in the bowl seem when you take the top off? How about the accelerator pump bladder and check valves? Does it flood after you shut it off or when it's running or both? Anyone else got other ideas about it flooding now that the fuel pressure is lowered?

Jim Brandberg
Isanti, MN
CorvairRepair.com



Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: Timothy Shortle ()
Date: September 28, 2019 06:50AM

Steve Goodman @ Rear Engine Specialists in Golden Colorado. 303-278-4889

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: nirvairna ()
Date: September 28, 2019 08:44AM

this is a longshot, but I once helped a guy with a turbo car that had no boost. turned out his turbo had an early "B" compressor wheel in the late "F" housing. car ran good, but no boost. the correct compressor wheel fixed it.

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: joelsplace ()
Date: September 28, 2019 09:38AM

Listen to Jim. You are wasting time messing with any other issues before fixing the flooding. You are actually making things worse attempting to tune to a flooding carburetor.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

Options: ReplyQuote
Re: Engine runs strong but no boost.
Posted by: DOUG WARD ()
Date: September 28, 2019 11:35AM

Tim, thanks for sending the contact info for Steve Goodman.
nirvairna, That is a good possibility. I haven't taken the turbo off / apart yet & I'll check into that.
Jim, & Joel, I think you are right on concentrating on the flooding problem 1st. I have checked & lowered the float level.The pump bladder is new & correctly installed. I've checked both check valves / ball check. The ball check is free & rattles. The valve in the late YH isn't a ball, it's a needle type in a cast in riser vertical cavity . It's smaller than the valve in the float. It's free & drops right out when the carb is inverted. The carb doesn't flood when the engine is off. It does flood after about 30 seconds after start up. constant dripping out of the throat of the carb. Like the float valve is not shutting off the fuel when the bowl fills up. I removed the original spring loaded valve & replaced it with a solid brass one. It is a little heavier. still floods.
I will stay with this stuff till I fix it. Thanks for you guys's interest & input. I'll keep you posted . Doug Ward

Options: ReplyQuote
Current Page: 2 of 4


Sorry, only registered users may post in this forum.
This forum powered by Phorum.