Edelbrock BBC RPM Airgap Intake - Water Bypass Ports

[1963c-10]

Ive built a 427 for my 63 c-10. Went w/an Edelbrock 7561 RPM Airgap Intake. My question is about the water bypass ports. What is the application of these? Should I just put 3/8 NPT plugs in? I understand that the water bypass ports allow the water to bypass the thermostat, just unsure of what the application is for. Does it have any benefit to a street engine/daily driver? The pic shows the ports very good, they sit between the last two bolt hole on the right side of the intake (as the pic sits) on either side of the distributor hold downs.. Thanks in advance

[1963c-10]

The research I 've found shows that it helps to balance out cylinder head temp and combustion temp

[storm9c1]

A 90's stock LT1 (SBC) has a coolant crossover/bypass in the back of the heads (up against the firewall). The would cross over the heads and then run up to the reservoir. LT1 is a reverse cooled engine though, so it may have been more important. Heck, if you can plumb it up, go for it. Or just plug it.

[1963c-10]

Thanks for the reply. Ive read pretty much what you said. Most of what Ive read says taht it helps get the hot water form the back of the block to the front. Helps balance out the temp of the engine across the board.

[Captainfab]

The thermostat bypass port is the port in front and below the thermostat. This is the one that connects directly to the water pump. The ports at the rear, are as you said, to help equalize/distribute the coolant.

[1963c-10]

but is it worth the time & money to plumb it for a street/daily driver? if it has any positive difference...temp, hp, etc....ill gladly plumb it. just wasnt familiar with it and wasnt sure if it was a race only application. ive had a few big blocks and understand the bypass off the pump. just wasnt something ive seen on cars at shows /cruisins w/same intake
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[cdowns]

i'd call edelbrock tech line for thier take on pros and cons and also to see if they have a snazzy custom part to do that job

[gofastnut]

I don't think it will hurt anything, and it will definitely look cool!

[1963c-10]

I can get the correct AN fittings and run the HP stainless hose for much cheaper than they will sell it for. Just saved $55 on a hydraulic cluth hose I built for my 63 c-10. Manufacture wanted $90. Without looking at it, I believe the intake ports are 1/2" NPT and probably be -08AN or -10AN hose.

[gofastnut]

Go to it!
But, we need pics please!

[1963c-10]

i think i will. probably be a week or two. i have to move the engine from storage at my engine builders to my house for final parts/install. i need to get the intake dimensions so i can order the fittings and hose. summit has water neck spacers that have duel ports for this application. im told the thermostat needs to go on top the spacer for it to be functional for this application
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[1963c-10]

longer water neck bolts, hose, fittings and water neck spacer should do the trick, now im trying to decide hose size. leaning to -8 or -10 an right now
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[1963c-10]

Ok, here goes. I used ARP bolts on my engine, so just ordered a set that were 1" longer due to the spacer for the water neck. The spacer is 1" with 2 - 3/8"NPT ports that I plumbed to -08AN hoses using 45deg fittings at the intake. I will mock up on intake once I bring the engine home next week. More pics to follow. I used 3/8"NPT-08An on the water neck spacer and -08 ends that go to the -08 - 3/8NPT 45deg fittings. Im not much on plumbing, but between this and plumbing the hydraulic clutch conversion in AN hose & fittings, Ive gotten better at it. The cost is more than rubber and hose clamps, but I think it looks great and will function as well.

[1963c-10]

ok, did initial mock up. i think i'll plumb a 90* instead of a 45* at the vacuum advance for more clearance and i want to put a little longer hose on the driver side. Its just a hair tighter than i want. Hose is only $5 a foot, so I have 3ft enroute and I'll use the existing fittings. I had to swap the spacer 180* as the build of the rpm air gap intake wouldn't allow sitting reverse without plumbling differnt. it also keep the hoses higher and more air around them instead of just laying on the valve covers.I like the look, and will know more results once its up and running

[meatwagon83]

better hope you dont need to turn that distributor to get it in time! i just put plugs in mine, you are the only person i have seen use them

[BossHogg69]

That's a nice looking engine you have there. The bypass lines look pretty cool too.

[Captainfab]

I agree

Might I suggest checking your throttle linkage position and travel. I'm thinking you might need to change the drivers side to a 90* also?

Originally Posted by BossHogg69

That's a nice looking engine you have there. The bypass lines look pretty cool too.

[gofastnut]

I had forgotten about this thread! It looks good! I know that guys with small blocks do it to get the hotter water out of the back of the engine faster, I think it will work well for a street application too.
Keep the info and pics coming!

[meatwagon83]

i know that valley is a mofo to keep clean!

[1963c-10]

Just realized I forgot to post a pic of the completed project on the water bypass system

[chvyboy]

Notice any difference in temp? Looking to do this on my 383 stroker. I need to have an efficient cooling system as possible and looking to upgrade my intake manifold to the air gap so why not try this bypass out right??? So I just wanted to check with you since you've done this!!

[1963c-10]

Originally Posted by chvyboy

Notice any difference in temp? Looking to do this on my 383 stroker. I need to have an efficient cooling system as possible and looking to upgrade my intake manifold to the air gap so why not try this bypass out right??? So I just wanted to check with you since you've done this!!

Sorry I just caught your follow up in the post. Just got the engine in a week ago, so I'll know more in the next couple of weeks after break in and driving it some. Heres a few follow up pics...

I have to reposition the HEI for clearance on the passenger side rear fitting, but no biggie. HEI will have to get pulled to prime the engine anyways.

[1963c-10]

Originally Posted by meatwagon83

i know that valley is a mofo to keep clean!

Yeah, I'm already finding that out.

[burnin oil]

I think the intended purpose to help relieve the coolant pressure from the back of the block at high RPM. We do a similiar thing on hi revving Cummins diesels. They don't return flow as fast as it gets pushed through the block and the pressure builds at the rear of the block. I actually shot a 2"+ freeze plug out the rear of the block before installing the bypass.

[1963c-10]

Good to know.....I may not get any positive effects, but at least no negative ones.