Check valve + Fuel pressrue regulator

Keep it on topic, it will make it easier to find what you need.
architect
Posts: 321
Joined: Thu Jul 21, 2016 9:48 am
Your car is a: 1978 Fiat Spider
Location: Austin, Texas

Check valve + Fuel pressrue regulator

Postby architect » Wed Aug 09, 2017 12:50 pm

Hey guys,

Im about to install a FPR on my 78. I keep reading more and more about the benefits of check valves.

Is it true it helps with vapor lock? Im in Texas and it gets HOT! (or is this the opposite effect, keeping fuel under the hood and heating it up?) :shock: OR is vapor lock eliminate if you have a supply and return? seems like if the electric fuel pump is running, your just circulating hot gas back into the tank, and pull colder gas back to the carb?

Also, where do I install it? I see on the micro slides = a few inches after the carb on the return hose.

Or if on supply, do I install before the FRP or after? I had it simply on the supply line before I ripped all the rubber out, and it worked pretty great, instant start ups.

Thanks!
78 Fiat 124

User avatar
kmead
Posts: 1069
Joined: Sat Aug 02, 2008 9:24 pm
Your car is a: 1969 850 SC 1970 124 SC 85 X19
Location: Grand Rapids, MI

Re: Check valve + Fuel pressrue regulator

Postby kmead » Wed Aug 23, 2017 6:22 am

On the supply it keeps fuel from siphoning back to the tank. I would put it before the FPR if you decide to run one. An FPR really isn't needed if you have a return line and use an electric pump which is in the normal range of pressure in the first place.

Having a return, particularly with an electric pump, allows constant flow at lower rpm which can minimize vapor lock.
Karl

1969 Fiat 850 Sports Coupe
1970 Fiat 124 Sports Coupe
1985 Bertone X1/9

architect
Posts: 321
Joined: Thu Jul 21, 2016 9:48 am
Your car is a: 1978 Fiat Spider
Location: Austin, Texas

Re: Check valve + Fuel pressrue regulator

Postby architect » Thu Aug 24, 2017 10:45 am

kmead wrote:On the supply it keeps fuel from siphoning back to the tank. I would put it before the FPR if you decide to run one. An FPR really isn't needed if you have a return line and use an electric pump which is in the normal range of pressure in the first place.

Having a return, particularly with an electric pump, allows constant flow at lower rpm which can minimize vapor lock.


Thanks for the info Karl! This was exactly what I was thinking.

Cheers
78 Fiat 124


Return to “Engine and Tuning”

Who is online

Users browsing this forum: No registered users and 49 guests