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W41 head to HO head

Posted: Tue Aug 29, 2006 10:20 pm
by KillerofRice
I wondering what the true benefits of the w41 head are compared to the ho head. I know the w41 heads produce 10 hp more and have a higher red line. What is also included in the swap. I remember reading somewhere the pistons had to be dished so the valves would clear. Is it true? I figure a new computer would probably be needed too. Just wondering. Please spare my ignorance .

W41 head to HO head

Posted: Tue Aug 29, 2006 11:21 pm
by 1988GTU
It's not the head that improves the power from a HO to a W41 it's the CAMS and CHIP.




W41 head to HO head

Posted: Wed Aug 30, 2006 4:03 pm
by blindmandesigns
The biggest benefit of a W41 setup is the transmission for pre 92 quad guys.  This will make a bigger difference then the chip/cams would by themselves.

W41 head to HO head

Posted: Wed Aug 30, 2006 10:23 pm
by KillerofRice
When I meant the head I was including the cams, because I was believe on ohc engines the cams are in the heads. I already know the cams and chip will improve power just wondering if the heads flowed any better or not.

W41 head to HO head

Posted: Wed Aug 30, 2006 10:32 pm
by 1988GTU
Unless SOMEONE ported the head....  A 086 head is a 086 head no matter how you cut it.  So what I am saying is find a 086 head with some W41 stuff and a 3.94 trans.
So the W41 should be a 086 head, & so should most High Outputs.  Just pop the IDI cover off and have a look.  
Look down there where the yellow is at in my picture:

W41 head to HO head

Posted: Wed Aug 30, 2006 11:18 pm
by KillerofRice
Thank you. That's all I wanted to know. So its basically a pull off the HO head and cams and put on the W41 stuff disregarding the chip. I know the tranny would be a big help to me. I read an topic on bstuff.com on that already.




W41 head to HO head

Posted: Thu Aug 31, 2006 6:51 am
by 1988GTU
If your head is a 086 head already, then all you need is the cams, chip, & trans.  While your taking the stuff apart and it seems you want the most out of this setup, you could have the head ported/polished too.  Then a header would be great.

W41 head to HO head

Posted: Thu Aug 31, 2006 7:58 am
by rweatherford
The 086 head is a year specific item, not W41.  The 93 W41 Achieva did not come with an 086 head and therefore was not 190 HP even with the larger cams.  The exhaust manifold and downpipe are also smaller on 93 model years.

Most other heads can be ported to flow as well as an 086 head.  I ran a 14.8 NA on a stock 753 head and HO cams.

W41 head to HO head

Posted: Fri Sep 01, 2006 11:20 pm
by Guest
If doing the HO - w41 cam swap, is it necessary to change the chip as well?

W41 head to HO head

Posted: Fri Sep 01, 2006 11:52 pm
by 1988GTU
This is what a 086 head looks like:



W41 head to HO head

Posted: Sat Sep 02, 2006 12:29 pm
by docrodg
You can do the swap without the chip on most cars as the computer will read the engine data and adjust the timing and fuel based on that, especially if you have a knock sensor on your car.  The performance chip simply changes the timing and fuel ratio for more performance.  Might have a problem if the car needs smoged on a performance chip tho, requiring a swap every year for the inspection.

W41 head to HO head

Posted: Fri Sep 08, 2006 1:59 pm
by blindmandesigns
Just putting W41 cams in with an HO chip will make the car run rich above I think 5500 and I think a little lean down low.  Aaron ran an HO MEMCAL with W41 cams and I think that is what happend.  

W41 cams make peak hp at 6800 vs HO's a 6200.  W41 chip has a 7450 Redline vs a 90's 6800 redline (7000 on 91 MEMCALs)  You wont want a chip in that will hit the limiter at the same RPM that the W41 cams make peak HP

I don't think it has been documented yet but I would imagine with just W41s and the HO chip your car will be slower. Plus the chips are only 60 bucks brand new from GM.

Issue with 90 and 91 GTZ's is that the W41 chip (made for an N-body) will throw a code 26 due to differences in relays for the quad driver circuit. The car will run ok and not be limping along but the coolant fan will remain on.  I got the schematics for an 91 N-body and my 91 L-body and see where the differences in wiring/relays are and will be going to the yard this weekend to pick up the N-body relay assembly to get ride of the Code 26.  

I have heard that a 92 ECM with a 92 W41 MEMCAL will work in a 90 and 91 L-body without throwing codes although I have only heard of one person who did this.  Worth a try but 92 quad ECM's are a little harder to come by in yards.

W41 head to HO head

Posted: Fri Sep 08, 2006 2:44 pm
by 1988GTU
Would it be possible to just have a memcal burnt for the 90-91 Beretta Q4 peoples to have the w41 specs plus a little more (If needed) changes?