Skip to main content ↑ ↓
Topic: Head clearance issues (Read 1406 times) previous topic - next topic

Head clearance issues

Alright so I new my head gaskets where getting tired. But the other day they got real bad/embarrassing. They are leaving a fog behind me. Maybe it looked worse cause I haven’t taking the car out for I while and it was cold out that day.
Anyway this is now a priority to fix. No big deal heres my excuse to put on my gt-40 heads and intake on off an explorer.
But now heres the problem I put in a trick flow stage 1 cam in in the spring. And just put headers on a few weeks back and while doing the headers I broke a spark plug. When I went to replace it I noticed the sparkplug was for an E6 head. So now I’m wondering if I have flat top pistons or eyebrowed .I know ill find out when I take the heads off but I want to take some educated guess here.
So hers the big question? Are they most likely eyebrowed because I would have had a clearance problem already. Or are the chamber sizes of the E6 deeper allowing me to get lucky so far and I don’t have a shot of getting the gt-40s on unless I change the pistons.

Head clearance issues

Reply #1 –
You probably have flat tops,and,I tried to install the GT40 heads,but they wouldn't work with my forged flat tops.So,I installed a set of ported E-7 heads.They're not GT40 heads,but they are leaps and bounds above the E6 heads.I also installed E-7 plugs.
'88 Sport--T-5,MGW shifter,Trick Flow R intake,Ed Curtis cam,Trick Flow heads,Scorpion rockers,75mm Accufab t-body,3G,mini starter,Taurus fan,BBK long tube headers,O/R H-Pipe, Flowamaster Super 44's, deep and deeper Cobra R wheels, Mass Air and 24's,8.8 with 3.73's,140 mph speedo,Mach 1 chin spoiler,SN-95 springs,CHE control arms,aluminum drive shaft and a lot more..

Head clearance issues

Reply #2 –
what short block are you useing ?
an SO and or and 86HO or are you useing an 87&up HO?

if it's an SO or 86HO it will have flat tops with no valve releafs..

if it's an 87&up HO it has flat tops with valve releafs..

but like you said you will soon find that out..

now for the cam.. if you have flat tops with valve releafs it will fit.. just not with out them.. iv'e see cams as large as .538IN & .543EX with 228&232 dur@.050  i'm useing a trick flow stage one so is Tom"turbocoupe50" and Bob "thunder306" and Ed "1FASTCAT" his cam is around.. i have the specs but not on this computer.. anyway is about .528IN & .534EX

Quote from: vinnietbird;115325
You probably have flat tops,and,I tried to install the GT40 heads,but they wouldn't work with my forged flat tops.So,I installed a set of ported E-7 heads.They're not GT40 heads,but they are leaps and bounds above the E6 heads.I also installed E-7 plugs.



what forged flat tops are you useing?

do yours have valve releafs?

like i said before about the cam meny of us use good street cams over .500 lift with street/race heads

Tom's useing TFS heads and i think he's useing an LSC HO which i'm not sure if it has flat tops with no valve releafs.. but he might chime in on this one.. i'm useing edelbrock 60379's which have 60cc chambers and 1.90IN valves and 1.60EX valves.. Bob and Ed are  useing 2.02IN valves with 1.60EX
only thing with Eddie's setup with the 202's is i'm not sure if he fly cut his pistons with the mid 5's lift cam that will be a little thight ..


Nick
Quote
there's only about a half a dozen man made objects that are herd by the human ear below 40Hz,a pipe organ,thunder,the space shuttle lifting off,a jet airplane taking off or landing,a large canon,an atomic bomb ignited in your back yard and the heat wave afterward oh wait you would be dead so you would'nt hear it scratch that!,and maybe beating your hear against a wall less then 40 times a second..rap music is'nt one of them!thats 40-60Hz@100+db the moving air is under 40Hz

Head clearance issues

Reply #3 –
Quote
Tom's useing TFS heads and i think he's useing an LSC HO which i'm not sure if it has flat tops with no valve releafs.. but he might chime in on this one..


TFS heads work with flat tops because of the way the valves (2.02 intake) are situated in the combustion chamber. Any other aftermarket heads need valve reliefs. You are right that 2.02 valve heads need bigger reliefs than the stock ones to work.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Head clearance issues

Reply #4 –
Good to know that TFS heads will work with flat tops. If I do have that problem but to try and simplify my question; is the depth deeper (chamber size) in E6 heads as in E7 or gt-40 or gt-40p or does it not matter.

Head clearance issues

Reply #5 –
Quote from: Innes;115367
Good to know that TFS heads will work with flat tops. If I do have that problem but to try and simplify my question; is the depth deeper (chamber size) in E6 heads as in E7 or gt-40 or gt-40p or does it not matter.


E6SE "cougar & first year HO 1986 allso known as the first turbo swirl heads"

and E7TE " truck and 87 and up HO heads"

should have the same "CC" which are 63cc

i don't remember what the Original 60's style GT40's had for cc

but the GT40's that where produced in the late 80's to the mid 90's where 65.5cc

the GT40p heads i'm not sure but should be from 63-65.5cc

and most bolt on Aluminum heads are 60cc but can be bought in 58cc

if you would like some good info check out this guys site

http://www.jason.fletcher.net/tech/tech.htm

http://www.jason.fletcher.net/tech/flowdata/castiron.htm


Nick
Quote
there's only about a half a dozen man made objects that are herd by the human ear below 40Hz,a pipe organ,thunder,the space shuttle lifting off,a jet airplane taking off or landing,a large canon,an atomic bomb ignited in your back yard and the heat wave afterward oh wait you would be dead so you would'nt hear it scratch that!,and maybe beating your hear against a wall less then 40 times a second..rap music is'nt one of them!thats 40-60Hz@100+db the moving air is under 40Hz

Head clearance issues

Reply #6 –
Thanks nick those sites look very informative plan on looking at them more. just got home from work now ill get some Zs and play later I think I’m going to take a plug out and drag a straw in there maybe ill get lucky and tell.

I guess the yes or no question I’m looking for in all of you best opinions is lets say for a giving that I do have the TFS-1 cam in with E6 heads w/no problems (pistons are flat or eyebrowed) or would of I had a clearance issues already, or is E7 and GT40 heads have flatter chambers and not as deep as the E6. Or is the depth the same on all equaling no problems. Or the TFS-1 cam will allow flat top piston and I’m worrying over nothing.

And yea I know I just spoke to much not making this a yes or no question.

Head clearance issues

Reply #7 –
i know this has nothing to do with it, and the 83 5.0 is a POS, but the pistons in that thing DID have valve reliefs... i was suprised


OOOH!!!  I'm a Eco Hypermiler :burnout: Not bad for 79mph on the interstate 2hours a day

Head clearance issues

Reply #8 –
I’m 99.9% sure now I have eyebrowed pistons. How I checked was I pulled spark plug #5 and a mirror and flashlight tried looking in and kept ¼ cranking the car for different depth of the piston at first I didn’t see any thing nor feel any thing by dragging a straw on top of the piston but just when I was about to quite I felt something that was consistent w/a eyebrow so I confirmed it by angling the mirror and flashlight towards it and bam there it was. Ill confirm it more when I take the head off but for now I’m going ahead w/ the GT40 head install.
 

Head clearance issues

Reply #9 –
Is this the original motor? Yes? - then they're flat, which is fine for GT40s, since I have them on one of my 88 T-birds. Don't know the spec.s on that cam though. You may need thicker head gaskets, but don't worry they won't affect performance, they just Minutely drop comp. ratio by VERY slightly increasing comb. chamber volume( like every .030" = -.1 in comp. ratio