Well, I'm trading a guy for items that would contribute to a DPFI to MPFI swap but when I got to check out the motor, the engine block read D15B6 (CRX HF motor). I found it odd since the CRX is an SI model so I go over to the ECU to verify and find PM6 (CRX/Civic SI) written on it. Now I'm not sure if the previous owner that had the car blew the engine and replaced just the block or everything (I've been researching the conversion and the HF manifold has something that restricts airflow compared to the SI mani). The car is MPFI but I'm not sure what attributes the SI manifold has over the HF. Please help with pointers. Thanks.

 

the hf manny is really small.. do you have any pics?

 

Wow... Title should read "How to tell the difference between an HF and SI intake manifold". I also found 2 very good pics between the two, but I'll ask anyways.

I noticed that in the pic, the Si mani has 3 outlets in the center, but the HF has only 1, and 2 more on the right side. Is this always the case regardless of the year the mani came off of?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kulangot &raquo;</TD></TR><TR><TD CLASS="quote">the hf manny is really small.. do you have any pics?</TD></TR></TABLE>

Sorry, none .

 

the hf has a egr valve on the manifold..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kulangot &raquo;</TD></TR><TR><TD CLASS="quote">the hf has a egr valve on the manifold..</TD></TR></TABLE>

He disconnected alot of stuff prior to me getting there, so I think the EGR valve was already removed (is it supposed to be stuck on, like welded and not bolted on)? Thanks.

 

it's bolted on, but there would be a plate if he took it off..

 

I believe that the runners on a si manifold are longer than a hf's.

 

the throttle body is small too, like 2"...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kulangot &raquo;</TD></TR><TR><TD CLASS="quote">the throttle body is small too, like 2"...</TD></TR></TABLE>

lol....it might be smaller than that. It looks like a golf ball would plug it up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kulangot &raquo;</TD></TR><TR><TD CLASS="quote">it's bolted on, but there would be a plate if he took it off..</TD></TR></TABLE>

I'll look into this. So there are EGR valves on all HF mani's regardless of the year?!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by marquisdee1018 &raquo;</TD></TR><TR><TD CLASS="quote">I believe that the runners on a si manifold are longer than a hf's. </TD></TR></TABLE>

I don't have an HF on me to check .

 

look, i'll end this thread for you...

if you can stick your ***** in there and fill the bore, it hf

other than that, its Si

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90_EF_Si &raquo;</TD></TR><TR><TD CLASS="quote">look, i'll end this thread for you...

if you can stick your ***** in there and fill the bore, it hf

other than that, its Si</TD></TR></TABLE>

But I'm asian so it wouldn't work for me..

 

Anymore helpful facts?!? Thanks in advance.

 

from my experience if you're looking at the manifold straight on,,the d16a6 si manifold has 3 vacuum **** with hoses in a row like l-l-l ...and the d15b6 hf manifold has those same 3 vacuum **** but its like this l-----l-l ...Do you understand what im saying or do i have to find some pics from my job?

They all go to the same components(Dashpot,Fuel pressure regulator and pcv valve)

on the si manifold though from left to right its dashpot-pcv valve-fuel regulator...But on the hf manifold its pcv valve------dashpot-fuel regulator..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMister_EF9 &raquo;</TD></TR><TR><TD CLASS="quote">

But I'm asian so it wouldn't work for me.. </TD></TR></TABLE>

ROFLMAO

 

this is an HF

 

Thanks alot guys. The pic is actually very clear, so I'll just look at the nipples and the EGR valve location to see what I'm looking at. Thanks again.