kevinek

I JUST PURCHASED AN 86 5.0 5 SPEED AND WAS GOING TO ORDER A HEAD,CAM,AND INTAKE PACKAGE FROM HOLLEY OR TRICK FLOW.I STARTED READING A FEW MAGAZINES AND SOME ARE SAYING YOU CANNOT RUN A BIGGER CAM OR A BIGGER VALVE IN THE 86 MOTORS BECAUSE THEY ARE THE ONLY YEAR MUSTANG USED FLAT TOP PISTONS AND THERE WOULD BE A PISTON TO VALVE CLEARENCE PROBLEM.HAS ANYONE HEARD OF THIS?ALSO I HAVE A RECIEPT WERE THE ENGINE WAS EXCHANGED A YEAR AGO.DO YOU THINK THE EXCHANGE BLOCK WOULD HAVE THE SAME PISTONS IF SO WHATS THE EASIEST WAY TOO TELL?ANY HELP WOULD BE GREATLY APPRECIATED.P.S SORRY ABOUT THE CAPS MY COMPUTER IS SCREWED.

I G Joe

i believe all you have to do is get pistons with valve clearances.

angcobra

Don't know anything about the pistons being anything special. Trick flow heads work with flat top pistons.

kevinek

THATS WHAT I WAS THINKING BUT IN THE MUSTANG MAGAZINE THE QUESTION FROM THE GUY WAS THE TRICKFLOW KIT AND THE GUY REPLIED NO LARGER VALVES OR BIGGER CAM WILL WORK ON THE 86 MOTOR.IS THERE ANYWAY TO TELL IF IT HAS FLATOPS WITHOUT PULLING THE HEAD?CAN YOU STICK SOMETHING IN THE SPARKPLU HOLE AND TELL?THANKS FOR THE HELP.

myshifter

ya you can use a coathanger and play around, if you know what your feeling for you can tell immediately if there are reliefs

tl86gt

all that you have to do is notch the pistons.... your local machine shop could do that for you. expect to see a HUGE gain with new heads cus the stock heads on '86's suck...alot.... i plan on doing a H/C/I swap myself if i can sell my damn fourwheeler

Twister

if you are going to pay money to notch the pistons, you can buy new ones for not that much more. if you are going to swap the heads, you will need new rings...personally, I would just rebuild the engine

Now, for what you really do not want to hear, other than the Isky cam that I am running, I have not seen a good cam for speed density. You can do any mod that you want other than the cam swap with speed density, if the cam is too big (not enough vacuum), the map sensor will put the computer into open loop, and you will have a ton of fuel poured into your engine, enough to melt plug wires.

last but not least, all capitol letters on the internet means that you are yelling

tl86gt

you can do a MAF conversion for like 300 bucks tho, cant you?

kevinek

Do you think the new exchange engine would have the flattops or would all the stock exchange 5.0s be the same and not built to the exact specs of the 86 motor?Also the isky cam you said your using with the speed density did it make a big difference?What heads did you use?

myshifter

just pull a plug and feel if there are reliefs, the chances of it having reliefs is 50/50, some remanufacturers are year specific if the client demands a certain year. others will just throw in a silvolite hyper or cast piston with valve reliefs