ITR/GSR intake manifold adapter plate

[GSRCRXsi]

well this is something ive been working on for a little while. basically i want to use the ITR intake manifold on the GSR head. why? well cause i want to race H1 Honda Challenge one day and their rules say you have to have a stock unmodified intake manifold. and im building my engine to HC specs so obviously ITR is the best choice. originally i planned to use this plate to adapt the coolant ports, but i decided not to do that and ill exlpain why later. the plate is 3/8" thick 6061 Aluminum.

i got the plate and used the hondata gasket as a stencil to drill the mounting holes. aparently the hondata gasket sucks balls as a stensil. i guess it doesnt have to be perfect since it just gets pressed on by the manifold. i had to fudge the holes a little bit but i got them all lined up now and it fits tight on the head which is all that matters.

next i lined up the intake manifold gasket with the hondata gasket to drill the correct holes in the ITR gasket. holes drilled and on the head to check fitment. perfect

now i would like to say something about drilling the holes. in the very little bit of information ive found about doing this (ITR mani on GSR head) it said that the bottom holes were the only ones that lined up. this isnt entirely true. they are the correct spacing yes, but they are a different distance from the ports. meaning that if you mount the ITR mani on the gsr head without reaming the bottom holes lower, the mani will sit too low and most certainly interfere with airflow. so when i lined up the gaskets to drill holes i made sure to base everything off the PORTS. if anyone out there attempts to do this, i cant stress this enough. dont fuck up your airflow for the sake of it being easier. its not even that much more work to do.

now another thing to note is that im going to abandon messing with the coolant ports. mainly cause making a passage through this plate would be too steep and very difficult to cut. to really be able to adapt them you need a thick plate, probably thicker then 1/2" and IMO thats too thick. so screw it. theres really no point in having that bypass anyway, its to help out in cold weather but my racecar never gets run in the winter. besides its less heat soak. now you may ask, why even bother with the plate? well besides the fact that im still adapting port shape, this is why...

the ITR mani doesnt even cover the hole on the gsr head. so the plate (along with a hondata race gasket) will cover the hole and keep any coolant from leaking out. plugging the hole isnt really an option as theres not enough material on that wall to hold threads. and im not welding it up. i really dont want to mod it at all. in case i ever want to sell it.

next thing i did was bolt everythying up to the head. one cause i wanted to see how everything looked. and two i needed to trace the ports for the ITR. seen below

and here it is with the ITR ports traced and the GSR outline traced. ready to cut.

now all i really have to do is cut it out, then screw with the port shape on the GSR side. and it will pretty much be done. i aslo have enough metal left to make another one, so ill probably do that and sell it or something. ill update as things progress . probably wont be for a few weeks since most of my tools are in baltimore. i dont have what i need here to cut the amount of material off that i need to at this point. let me know what you think

 

[B16RacerN2NR]

very nice good job and great info

 

[B16]

That is nice.

 

[GSRCRXsi]

lol, youre teh ghey mike.

 

[posol]

ok so u r going 2 weld this on the itr im ?

 

[GSRCRXsi]

no. its sandwiched between the manifold and the head. will have the hondata gasket on the head side and the ITR gasket on the mani side. the plate is mainly there to block the coolant hole. i COULD have used a thinner plate, but i originally planned to make a coolant passage, but its going to be too steep to do.

 

[posol]

um ok, how do you bolt it on?

 

[civicious]

Quoted post[/post]]
ok so u r going 2 weld this on the itr im ?

Yeah...how are you gonna attach the ITR manifold? I'm not getting how that adaptor plate is any different than a gasket at this point

 

[vtecsir1]

im thinking he redrilled the itr manifold because of the modified gasket shown?

 

[GSRCRXsi]

yes the manifold will be redrilled to the GSR pattern. if it wasnt for the coolant ports being way off i would just deal with redrilling the manifold and bolting it on. HOWEVER the ITR mani doesnt even cover the hole. so if i did that coolant would just shoot out everywhere. so the plate will be there to block it. understand now? this is why i said earlier that i could use a thinner plate but when i bought the plate it was my intention to make a coolant passage through the plate. but like i said its gonna be too steep to be able to do. well with my resources anyway. if you look at the picture you can see how far off the passages are for the 2 manis.

also i cant just use the race gasket (no coolant hole) to cover it up because i suspect it isnt rigid enough to hold the hole closed. especially since the hole is for the most part uncoveredby the mani so theres nothing applying pressure over the hole. so having a rigid (relatively speaking) AL plate on there should hold the hole closed and prevent any coolant from leaking out.

 

[posol]

Ok, so you're re-drilling the mani. that makes more sense...

but doesn't that count as modified? adding a spacer in between the mani might not pass....

 

[GSRCRXsi]

redrilling is allowed. its specifically stated in the rules that it is. you can also portmatch the manifold but not more then 1" into the manifold. yea its kinda up in the air right now about the spacer. some people think its illegal, some people think its not. theres nothing in the rules allowing or disallowing it.

 

[posol]

adding that thickness will change the velocity and length of the ports, so technically, its midified...

 

[B16RacerN2NR]

Quoted post[/post]]
adding that thickness will change the velocity and length of the ports, so technically, its midified...

that's what I was thinking.

Also, when I used the AN-R gasket it was about a quarter inch think and when I put the ITR manifold on, the studs were sticking out about half an inch so it just barely gave me enough room to thread the nuts on. Hopefully your plate isn't too thick.

 

[B16]

Quoted post[/post]]

Quoted post[/post]]
adding that thickness will change the velocity and length of the ports, so technically, its midified...

that's what I was thinking.

Also, when I used the AN-R gasket it was about a quarter inch think and when I put the ITR manifold on, the studs were sticking out about half an inch so it just barely gave me enough room to thread the nuts on. Hopefully your plate isn't too thick.

I think he has extended studs on his head.

 

[civicious]

Quoted post[/post]]

Quoted post[/post]]

Quoted post[/post]]
adding that thickness will change the velocity and length of the ports, so technically, its midified...

that's what I was thinking.

Also, when I used the AN-R gasket it was about a quarter inch think and when I put the ITR manifold on, the studs were sticking out about half an inch so it just barely gave me enough room to thread the nuts on. Hopefully your plate isn't too thick.

I think he has extended studs on his head.

He's got 2-foot long studs. It'll fit.

 

[GSRCRXsi]

lmao. they arent THAT long. just your standard 50mm studs, lol. in my build thread i have a pic of them next to the stock ones so you can see how much longer they are. but B i cants see 3/8" making THAT big of a difference. and besides its not changing anyhting on the actual manifold so i dont see it being an issue.

 

[B16RacerN2NR]

Quoted post[/post]]

Quoted post[/post]]

Quoted post[/post]]

Quoted post[/post]]
adding that thickness will change the velocity and length of the ports, so technically, its midified...

that's what I was thinking.

Also, when I used the AN-R gasket it was about a quarter inch think and when I put the ITR manifold on, the studs were sticking out about half an inch so it just barely gave me enough room to thread the nuts on. Hopefully your plate isn't too thick.

I think he has extended studs on his head.

He's got 2-foot long studs. It'll fit.

ah, I see said the Blind Man.

 

[97CTR]

there is a guy on HT who sells these adapter plates for like 75 bucks. Just a price reference if you decide to sell some.

 

[GSRCRXsi]

yea i dont plan to sell these at all. right now pretty much the only reason for the plate is to cover the coolant hole on the gsr head as the itr mani wont.