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Re: Datsun 240z with L20ET
Posted: Fri Jun 10, 2011 1:00 am
by antus

- overheat.jpg (453.82 KiB) Viewed 7710 times
This would be why it was overheating... Some of the head bolts were definately not torqued enough, and it was the wrong gasket, missing many holes for proper water flow. So krud had just piled up in there....
Re: Datsun 240z with L20ET
Posted: Fri Jun 10, 2011 1:30 am
by delcowizzid
gotta love the rusty mud you should see how much comes out of a v6 buick when you pull the frost plugs its like they are grout filled LOL .i pop all the frostplugs and water blast all the water jackets via the holes i do the same in the heads too before even fitting them into cars now
Re: Datsun 240z with L20ET
Posted: Fri Jun 10, 2011 8:23 am
by Jayme
frostplugs? you mean welsch plugs?
Re: Datsun 240z with L20ET
Posted: Fri Jun 10, 2011 12:21 pm
by Holden202T
yeah that NZ speak
Antus that is some nasty looking crud! i don't think it will take much to improve on that situation!!
Re: Datsun 240z with L20ET
Posted: Fri Jun 10, 2011 12:33 pm
by antus
We got Ross's home vacuum cleaner, stuck it in to a nearby empty coolant bottle (sealed it with tape), then made a thinner collector pipe also coming out the top of the bottle, and used that arrangement to suck the crap out the block and collect it in the coolant bottle. Worked pretty well for an ad-hoc solution, but next time we try it we reckon we can do it better.

It was a funny situation!
Re: Datsun 240z with L20ET
Posted: Fri Jun 10, 2011 10:10 pm
by VNracer34G
Now thats a hard case way to do it allright

might as well do some work on the head while its off and replace those FROST plugs and hose it out as delcowizzid suggested, more power = more heat so the cooling system needs to be in good shape - awesome effort guys, btw whats that writing on the doors?
Re: Datsun 240z with L20ET
Posted: Fri Jun 10, 2011 10:24 pm
by antus
Well, this one we'll just re-assemble and run it for another couple of track days. We have a L28E lined up to replace this whole engine, and thats the one were doing for keeps. We have an MLS head gasket on order, and its in bits now to get the head chemical treated and to get it cleaned up as best we can. Then we'll run that with the same bolt ons, and if thats all good, then start upping the boost and see how quick we can make it.
The writing is "Garage of Awesome". Our race 'team' (even though were just practicing at this stage), and also Ross's and another mate Dave's car blog and business. They've got some interesting reading as well as import and local cars for sale over at garageofawesome.com.au - well worth a look if your looking for some interesting storys or another set of wheels.
Re: Datsun 240z with L20ET
Posted: Sat Jun 11, 2011 2:59 am
by Six_Shooter
IIRC there was a revision to the headgasket that had less coolant passages in it to force the water to flow all the way through the engine to reduce the hot spotting of cylinders 5 and 6. The problem was that with many holes between the head and block, would allow coolant to flow through the engine without flowing past the rear cylinders.
There are also some cooling tricks to force water flow to the rear of the head to help reduce the hot spotting as well.
Re: Datsun 240z with L20ET
Posted: Sun May 26, 2013 6:42 pm
by antus
It looks like we did not update this thread with the end of the saga. It turned out that the head gasket was not the problem, we had been sold an engine with missmatching head and block. The water galleys did not line up at all, and there was nothing we could do about it.
So we have been working on other projects, but we have acquired a good L28ET and swapped the delco gear on to it and got it in the car. We've installed some larger Ford XR6T injectors which should deliver enough fuel and hopefully the next update will be good news.
Re: Datsun 240z with L20ET
Posted: Sun May 26, 2013 7:24 pm
by VX L67 Getrag
Nice work Antus, this site really needs a price per hit value as everyone here is too under valued!!
HONESTLY all the mods here go above & beyond & I & most here try & give back as much is put out!