1HD-T Intake Manifold Modifications

[Wildnlost]

Great concept. I think you could make some flow improvements on the intercooler turbo side. But the rest looks great.

Thanks Dougal. I cut up a Mazda speed6 intercooler that I had in spare parts to make my creation. The turbo side was constructed first and I recycled the tank end cap thinking it was easier than fabricating the whole end tank. After fabricating the dual outlet end tank from scratch I wish I would have done the same on the turbo side. I could have made a longer radius entry and smoother path before entry into the charge cooler.
Using sheet aluminum and a few purchased fittings it was easier to fabricate exactly what I wanted on the outlet side vs recycling the existing pieces that I had butchered off the intercooler.

I only have simple shop tools and I had someone else weld it up.

On a little different note....
Working with limited tools is always fun. I couldn,t justify buying a beading tool to make two or three pipes ... I googled beading and found this simple idea. Grind up a pair of butt connector crimping pliers and a with a little practice its fairly easy to make functional beads.

Cheers

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[Nathjf88]

Did we come up with what the best size is to weld on to the manifold. 3 or 3.5 inch ? About to cut mine up this week..

 

[gerg]

I'd like a bead tool like yours except one strong enough to do 18ga stainless steel. I usually lower my mig temps and run a small bead instead. Works great but much more time consuming.

 

[Wildnlost]

I'd like a bead tool like yours except strong enough to do 18ga stainless steel. I usually lower my mig temps and run a small bead instead. Works great but much more time consuming.

The Channelock brand is very robust, I would try it. Dont grind the the pliers until you try it. Grinding off the end was necassary for clearance to close bends. If you cant do it from a force standpoint you could narrow the bite of the pliers to increase force. For intake plumbing I only did 4 dimples per end

 

[vwluv10338]

Did we come up with what the best size is to weld on to the manifold. 3 or 3.5 inch ? About to cut mine up this week..

Bigger is better I guess but I ordered 3" for mine

 

[mudgudgeon]

I'd like a bead tool like yours except strong enough to do 18ga stainless steel. I usually lower my mig temps and run a small bead instead. Works great but much more time consuming.

Greg
You could wrap a small strip of annealed copper flat bar around the end of the pipe, and run a weld bead up against it, then remove the copper.
It would leave you with a sharp(ish) shouldered bead for the hose and clamp to tighten against.
Set the bead facing away from the end of the pipe for better anti slip.

I agree on the channel lock brand being real tough. Almost sacrilege to cut them up!

 

[Mcreight911]

What I used before I had a bead roller . Found it a bit easier than the pliers style on thicker pipe . Still slow though

 

[Nathjf88]

Bigger is better I guess but I ordered 3" for mine

I plan on running 35 psi. I need a bit of air reserve for smoke control. A machined and flowed head and modified Piston bowls brings plenty of low down but likes to smoke abit lol

 

[gerg]

Ahh thanks they great advice. Probably be easier to just use aluminum but I've got a bunch of stainless to get through. I do like it cus it's tuff and you don't have to be super paranoid about it touching stuff in the compartment and wearing a hole.

 

[vwluv10338]

I plan on running 35 psi. I need a bit of air reserve for smoke control. A machined and flowed head and modified Piston bowls brings plenty of low down but likes to smoke abit lol

Damn. Sounds like you are going way beyond what I have planned. I'm just aiming for 20psi and want my cylinders to get an equal share of the air.

 

[Dervis Garip]

Custom Intake manifold & new intercooler setup finished.

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[Totti Power]

Hallo,
3 Jahre Arbeit
HZJ 78 & 1HDT
michael

 

[Totti Power]

Ergebnis===!!!

 

[Wildnlost]

Ergebnis===!!!

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Nice work. Tres bon.

 

[macca1590]

Can anyone tell me the alloy thickness of the manifolds? id like to modify my spare 1hdt manifold and just working out the best thicknes for the tube wall before i buy anything. Thanks

 

[Wildnlost]

Can anyone tell me the alloy thickness of the manifolds? id like to modify my spare 1hdt manifold and just working out the best thicknes for the tube wall before i buy anything. Thanks

Pretty thin about .100" I think

 

[surfari-LC80]

Hallo,
3 Jahre Arbeit
HZJ 78 & 1HDT
michael

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Nice work! Do you have any more pictures of the individual runners?

 

[Rugy]

just finished reading a 22 pages.
Very informative and thanks to all that have posted here.

 

[macca1590]

Has anyone done any back to back testing of a modified intake yet? like afr/egts even power and torque? I did find this on a Patrol form talking about manifolds on the TD42 diesels, completely different animal i know but the manifold on them looks just as horrid as ours haha.

""""""I have never tested with BB turbo but for my KKK it doesn't do anything to the off idle response but once the system gets past about 6 to 8 psi you will see a sharper rise in torque. What i did record was the turbo did reach its set max boost point for my slow spool turbo about 100rpm lower. What the manifold does is lower your over all egt's some 100 to 150 C at 22psi also it increases your AFR's a point or two at max torque rev point. And for all manifolds i have made and tested, torque it slightly higher but more to the point it is spread over a larger rev range in other words it flattens the torque curve hence better driveability."""" quote some nissan guy

 

[Mcreight911]

Very similar results on the 1h engines as well . With the right design it Promotes cylinder filing and evens flow between the cylinders.