86 GT roller rocker question

[redknight290]

A buddy of mine has a set of roller rockers layin round that he offered me but said he doesn't remember the ratio of them. The part number on stamped on them is F3ZF-6529-AB and they are made by crane. If they are 1.7 will they work on an 86 gt motor.

thanks to all.

 

[Deleted member 87397]

They sound like they are from a 93 based on the F3 part number. They were either stock rockers on regular 5.0's or the Cobra. that's all I know. I can't remember if the Cobra ones were 1.6 like regular or if they were 1.7's

 

[83T-top]

They sound like they are from a 93 based on the F3 part number. They were either stock rockers on regular 5.0's or the Cobra. that's all I know. I can't remember if the Cobra ones were 1.6 like regular or if they were 1.7's

The 93 cobra rockers were 1.7. If the rockers you have are 1.7 then it will change the lift of the valves. Your stock HO cam should be around .444 lift going to the 1.7 would put it around .474 lift. The only thing you have to worry about is the 86HO engine didn't have any valve reliefs in the pistons, I know you can go with a little bit more lift with the pistons, but I don't know how much some stuff I've read says about .500 lift max on the pistons, but I'm not 100% sure. Are you planning on doing any other mods?

 

[Vinnietbird]

The 1.7's should work fine with the stock cam.I have an '86 engine,E-7 heads,and an E303 cam.It's been fine.I have 1.6 roller rockers on mine.I'd run the 1.7's if I had the stock cam.

 

[Deleted member 87397]

The 1.7's should work fine with the stock cam.I have an '86 engine,E-7 heads,and an E303 cam.It's been fine.I have 1.6 roller rockers on mine.I'd run the 1.7's if I had the stock cam.

Are your pistons notched? I'd be amazed if they weren't on a combo like that.

 

[Vinnietbird]

Flat as a board. No notches.I was surprised as well.BUT,It works and the car pulls really well,especially after we did the 5 speed swap.I've had it up to 6000 rpms and no damage.I can't say that will be exactly the same fore everyone.It does work for my engine though.

 

[Deleted member 87397]

Flat as a board. No notches.I was surprised as well.BUT,It works and the car pulls really well,especially after we did the 5 speed swap.I've had it up to 6000 rpms and no damage.I can't say that will be exactly the same fore everyone.It does work for my engine though.

Wow, that opens up some possibilities for me that I have not considered. How tight do you thing your P2V clearance is? Did you put those E7's on yourself and know they are totally flat for sure?

 

[v8only]

Wow, that opens up some possibilities for me that I have not considered. How tight do you thing your P2V clearance is? Did you put those E7's on yourself and know they are totally flat for sure?

don't get too excited. I've PERSONALLY had 2 local friends with stock 86 bottom end 5.0 motors that ran into direct piston to valve smack on install....luckily they had clayed it up first.

it seems to be a 50/50 shot.

That's why I trashed my entire 86 engine for an explorer gt40p longblock.

If I still had the old 86 motor, imo the best thing you can do for it is just spray a bunch of nitrous until you can afford a motor with notched pistons. at least the pistons in the 86 are forged and can handle nitrous.

I wouldn't waste my time with those 1.7's.....not enough power increase for the risk.

 

[Deleted member 87397]

Ha! that's always been my plan. I'm just going to nitrous the hell out of it till it breaks and then do something new.

 

[v8only]

Ha! that's always been my plan. I'm just going to nitrous the hell out of it till it breaks and then do something new.

good plan....those flat top pistons make that entire engine a boat anchor for anything other than spray (tfs heads will work if you have the $$$)

you can also get a tool that notches the pistons in the block...something also worth considering.

as well, you've got a restrictive 58mm upper intake and throttle body. swapping that out for a 60mm 87+ throttle body and upper will help (lowers are the same)

 

[Vinnietbird]

I had the heads ported and a valve job done with new seals and they made sure the heads were true.I pulled the heads off of a truck at the boneyard and wanted them taken care of before I installed them.ANd yes,I did install them myself using new head bolts.