• Hello there guest and welcome to our forum!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

b heads vs c heads

E

ears

Well-Known Member
i noticed that we dont have anywhere on here, (that i saw), a thread discussing the differance in heads for the 4v cars!! now according to my research,,, there are three differant types of 4v heads,,, by no means is this definate, but this is what ive found!!

there are b style heads,,, which are on the earlier 4v cars up to 98,

there are the c style heads,,, on the 99 and up 4v cars

and then there are the navi heads,,, so to speak on all the 5.4 cars

so honestly,,,, what are the differances??
what ive read is that the the b heads are really hot for boost,,,, and the c heads are great na. which surprised the hell out of me since the c heads generally come boosted, and the b heads generally come na!!

going further into the conversation,,,, what are the differances,,,, machining wise?? in other words,,, what would it take to fit up,,, lets say a b manifold to a c head,,, and visa versa??

i know that they say you cant bolt up a termi intercooler to a b head. but why?? if any one has a few real good pics of a c head including the intake flange, i can put up some good pics of a b head!! and we can compare a bit closer from there!!

thanks in advance,,, and i know we can get some great info from this!!
 
E

ears

Well-Known Member
alright this is what i have so far!!

B HEADS

like i said,,, these are great blower heads!!!
they are split swirl port as they say,
one dry port and one wet port,
they use imrc plates for torque controle,
the imrc's open at 3250

under 5000 these heads flow worse than the c style heads,,
then above 5000 they flow i think they said about 3-400 cfm better than the c style,,, (dont quote me on that)

now looking at just this bit of info i see why these are better blower heads,,, if they live in the upper rpm range then theyre perfect to throw a blower on especially a centri, where the blower can be a great atribute to the higher range,,,

C HEADS

these heads like i said,,, are better na heads,
they do not have imrc's
and the reasoning behind this is they have a more improved merged tumble port intake design

this allows them to flow better than the b heads below 5000,,, (how much im not sure) and not nearly as well ubove 5000!!






this is just a very little bit of info that i had researched in the past to get us started here,,, but well see where it goes and see what we can figure out about these heads!!

and again,,, some pics of c heads would be great,,, especially the intake,,, seeing as that seems to be where the biggest differances are!!
 
atlblue98gt

atlblue98gt

Greer, SC
they say the 2v trick flow heads outflow B heads. Thats what I'm gooing with next before I go supercharged. I wanna be 400 hp NA.....

Baack on topic. Some good ?s
 
E

ears

Well-Known Member
good article yes,,,,, but i want to go deeper into this,,,, ive already read that in a few differant posts on a few differant websites,,, alot of good info, and a long read. but well worth it!! this article gives general info about each head.

the end goal of this thread is to either confirm or undoubtedly say whether or not you can get past the faults in each head,,,, and to compare them in more depth!! i look all over the internet and i see bits and pieces of where people have started to look into this but havent gone very far with it!!!
 
E

ears

Well-Known Member
sry if the above doesnt make too much sence,,,,,,,,,, but it sounds right in my head. it just doesnt look quite right typed out.
 
You must log in or register to reply here.
Top