Coolant Bypass

Tech tips and how to's

Moderators: notoptoy, garth, S Allen

VonMussa
Roadster Newby
Posts: 14
Joined: Fri Sep 27, 2019 9:00 pm
Location: Grand Rapids, MI
Model: 1500/1600
Year: High Windshield-68-70

Coolant Bypass

Post by VonMussa » Tue Oct 08, 2019 10:40 am

As I work through this, just confirming the coolant is bypassed appropriately around to avoid the heater?
You do not have the required permissions to view the files attached to this post.
Matt Erck
Grand Rapids, MI

1968 Datsun SPL311
2010 Toyota 4Runner Limited
2016 GMC Yukon XL
2020 Airstream Flying Cloud 30' Bunk

JT68
Talented Enthusiast
Posts: 1903
Joined: Sun Jan 27, 2013 9:43 am
Location: Cumming, GA

Re: Coolant Bypass

Post by JT68 » Tue Oct 08, 2019 2:52 pm

Yes, that is fine, won't hurt anything if you are looking to bypass the heater for a while.
JT/LT
Datsunrestorationproducts.com
The very finest parts for your 311!

VonMussa
Roadster Newby
Posts: 14
Joined: Fri Sep 27, 2019 9:00 pm
Location: Grand Rapids, MI
Model: 1500/1600
Year: High Windshield-68-70

Re: Coolant Bypass

Post by VonMussa » Tue Oct 08, 2019 3:24 pm

Appreciate it. Bought it and trying to unpack whats been done right, and whats been done wrong.
Matt Erck
Grand Rapids, MI

1968 Datsun SPL311
2010 Toyota 4Runner Limited
2016 GMC Yukon XL
2020 Airstream Flying Cloud 30' Bunk

JT68
Talented Enthusiast
Posts: 1903
Joined: Sun Jan 27, 2013 9:43 am
Location: Cumming, GA

Re: Coolant Bypass

Post by JT68 » Tue Oct 08, 2019 4:49 pm

Long term, I'm sure you will want a heater and water through the manifold I'd think, but that will work fine for now.
JT/LT
Datsunrestorationproducts.com
The very finest parts for your 311!

VonMussa
Roadster Newby
Posts: 14
Joined: Fri Sep 27, 2019 9:00 pm
Location: Grand Rapids, MI
Model: 1500/1600
Year: High Windshield-68-70

Re: Coolant Bypass

Post by VonMussa » Tue Oct 08, 2019 5:04 pm

Yes. Definitely need a heater living here in Michigan. Top down as the snow falls is my goal
Matt Erck
Grand Rapids, MI

1968 Datsun SPL311
2010 Toyota 4Runner Limited
2016 GMC Yukon XL
2020 Airstream Flying Cloud 30' Bunk

User avatar
mshort07
Roadster Fanatic
Posts: 183
Joined: Mon Jul 23, 2012 8:45 pm
Location: Urbanna Va

Re: Coolant Bypass

Post by mshort07 » Tue Oct 08, 2019 6:56 pm

It was suggested to me by someone on this site to bypass the heater core after the coolant passes through the intake manifold and just before it enters the heater core. The individual suggested that the heated coolant in the intake manifold helps to preheat the air fuel mixer entering the combustion chamber.
Matt
Urbanna VA
1969 SRL311 / 1967 SPL311 - Resto Project
1967 SPL311 - Donor Car - long gone
1968 SRL311 - Donor Car - long gone
1968 Datsun 520 pickup
1993 Jeep

User avatar
Nissanman
Roadster Fanatic-Site Supporter
Posts: 3004
Joined: Mon Apr 16, 2007 8:07 pm
Location: Adelaide, South Australia
Model: 1500/1600
Year: Low Windshield-64-67.5

Re: Coolant Bypass

Post by Nissanman » Tue Oct 08, 2019 8:14 pm

From what I have read, the heated manifold [throttle body on EFI engines] is designed to minimise the likelihood of the throttles jamming open due to icing up in humid climates.
Nissanman, just trying to help.
1965 SP310 Engine No. G-93326 Car No. SP310-10817
http://nissanman.shutterfly.com/117
McQueen!
He's on the road again!

JT68
Talented Enthusiast
Posts: 1903
Joined: Sun Jan 27, 2013 9:43 am
Location: Cumming, GA

Re: Coolant Bypass

Post by JT68 » Tue Oct 08, 2019 9:15 pm

Coolant through the manifold simply regulates the intake manifold temp. Helps warm up the intake and carbs in the winter, keeps the manifold cool in Arizona. Plenty of cars run dry manifolds, but if you are running the car in extreme temps, a wet manifold is a good plan.
JT/LT
Datsunrestorationproducts.com
The very finest parts for your 311!