Whats the point of this?

[LeDevil]

I removed my exhaust manifold and then the intake manifold and noticed no coolant leaked like Datsuns normally do. Well once both were removed I noticed someone had drilled and tapped the water out lets on the head and put plugs in them :confused: I was able to get one out but the other was rounded off "allen head" But coolant did start to leak out of the one I got out. So not being able to get the other out I put the other one back. So can anyone tell me what was the point if any of blocking those water passages off?

Edited January 2, 2009 by LeDevil

[DISLEXICDIME]

you really need to watch hainz's video and do some reading ! sign up on datsun 510.com and read the how to hotrod and race your datsun 510 book. it is under free online manuals. also join the bluebirds mailing list. and when you are on datsun510.com you can access the blue birds mailing list archive. when you are there use the search you can find out a lot of stuff.

 

the reason those plugs where there where so you didnot have to run coolant through the intake.

[Bleach]

The head was swapped. It used to use the older intake manifold which is water heated. Now you must have the intake that is exhaust heated.

[banzai510(hainz)]

early L motors had water passage holeto heat the manifold.There will be a metal hotwater line from where the lower rad hose is to the block. there will be a T which it routes from. this prevented carb icing

 

Later L20s I believe had a 2 pc intake and exhaust manifold bolted together which used a heat riser. Like a old wood stove plate that would open /close. the heat raised up the heated the the intake . So no water passages where in the head.

 

as people modified the cars with sidedrafts that had the water passages and didnt need them it was nicer to have them plugged with 1 /4 inch Pipe plugs

1/4 inch was the allen size actually.

 

If you run sidedrafts(Dcoe.or Mikunis) You want them plugged. Well its ezer to keep the water from leaking without over torqing the bolts down as a aluminum head could strip out the threads

 

SU carbs have a heated water line also.

 

I dont know what your running so I assume just put it pack to what is was.

 

 

I just depends on where and what you run. If you have a later NO water port head , live in a cold area ,run a weber DGV or stock carb you would want to drill holes(1/4 inch is fine) in the head and run the metal water line so your carb dont ice up.

[LeDevil]

It's a L16, it has the intake manifold with water ports in it, It's also running a Weber 32/36. The only reason I asked was because I thought something might have been rigged to pro long the use of the motor. Once again thanks for the help guys

[datzenmike]

The warmed intake won't really prevent ice forming 6" higher up on top of the venturies. It will help vaporize the fuel and warm the intake charge and aid engine efficiency. My '78 has the water heated runners and suffered from icing until I rigged up warmed intake air from the exhaust manifold.

[banzai510(hainz)]

I had a Jap spec L18 with no water passage and ran it.

I had a DGV that would ice up(rainy just above freezing)

Car would cut out. I lifted the hood and it was frosted .

 

as tock aircleaner with the exhaust hose would have helped, but most go in the garbage!!!!!!!

[datzenmike]

I find the stove pipe hoses just disintegrate or fall off when people take the air filter off. Never even thought about mine. It would run shitty every now and then until one night (freezing rain) kept acting like it was running out of gas. No power, pedal going further and further to the floor. Would run real good if you could get the 2 bbl open. I was pissed off, had to get somewhere fast! Pulled the filter off and the venturi was a ball of frost like the inside of a freezer. I rubbed it off and away I went... for three blocks. Did this 2-3 times. I pulled the cool air hose off the air snorkel and that I had on it and it now used slightly warmed air from behind the rad. Wasn't great but I got by. Next weekend I made an exhaust shroud from a Maxwell house tin and some hose.

[ggzilla]

Yep, Mike's correct. The water-heated manifold is not to prevent icing. Instead, the heated air intake does that. Heating base of manifold via water is done to improve fuel economy and by having a more stable temperature can lower emissions with careful tuning.

 

Ratsun style would be to plug those holes back up, then start driving again. It doesn't actually need to run water to the manifold ...