Do I need to find TDC when doing heads, but not cam?

N8Miller

I need NOS....make it 2 of the big ones
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Jul 26, 2000
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Kingston, PA, USA
as stated above, i am swapping heads on my cousins 86, doing gt40 iron heads, 1.7 rockers and putting his ported gt40 intake back on. The heads are gasket matched and have a 3 angle valve job. Do we need to find TDC again or just put the heads back on because we are not swapping cams!

thanks in advance..
 
Well, if for no other reason you need TDC to set the distributer back in. Unless of course you marked it where you pulled it. Also, wehne putting in the 1.72 rockers you will need to rotate teh motor to adjust them when you put them on. You sure are a long way in not to put a timing chain and cam in, why not do it while you are there?

Finding TDC is pretty easy, especially if you are replacing the heads, why are you worried about it?
 
Mark where the rotor is pointing on the distributor base with a nice black sharpie marker. Pull the distributor and get to work... Just don't rotate the motor.

But if you do, it'll be easy to find TDC with the heads off. Then just restab it in the #1 position.
 
srothfuss said:
Mark where the rotor is pointing on the distributor base with a nice black sharpie marker. Pull the distributor and get to work... Just don't rotate the motor.

But if you do, it'll be easy to find TDC with the heads off. Then just restab it in the #1 position.
totally correct. it is easier and takes the guesswork out of timing the engine if you find tdc in the first place before the swap. it doesnt matter unless you rotate the engine.
 
N8Miller said:
as stated above, i am swapping heads on my cousins '86..

If your cousin still has the factory pure flat top pistons in his '86, checking piston to valve clearence is an ABSOLUTE MUST!!!!

There's pretty much a 100% chance that the GT40 heads will not clear the pistons with out notching them for valve reliefs.

The only head that is a bolt on for the with no clearence issues are TFS TW's. Some have gotten away with using stock '87-up E7 heads with the factory cam, but it's a hit or miss kind of deal. P to V check is a must do with them as well.
 
thanks for the replies.

as for marking the dist before pulling, i did not. my cousin just unbolted it and before i could mark it, he yanked it.

as for the cam mention: it still has the stock pistons

95gtaode: actully, some one this board are running TFS heads and an e cam on the stock pistons.....
 
Yes. You should rotate it to tdc #1 before you pull the engine apart.

If not, you'll have to put the new heads on and rotate the engine til you feel air comming out of the #1 spark plug hole and the balancer will be at 0*. Theres no need to mark the distributer, just mark the plug wires.
 
95GTAODE said:
If your cousin still has the factory pure flat top pistons in his '86, checking piston to valve clearence is an ABSOLUTE MUST!!!!

There's pretty much a 100% chance that the GT40 heads will not clear the pistons with out notching them for valve reliefs.

The only head that is a bolt on for the with no clearence issues are TFS TW's..

This was the quote from earlier, although I am not sure whether it will work or not it is always a great idea to check valve to piston clearance when installing new heads, cam, or rebuilding the motor. The lat thing you want to do is find out after the fact taht it wont work.
 
N8Miller said:
95gtaode: actully, some one this board are running TFS heads and an e cam on the stock pistons.....

Re-read my post... I stated that the TFS heads are the ONLY head that is a bolt on for the '86 with no piston to valve clearence issues.

When I mentioned only using the stock cam, I was refering to people who have succesfully used '87 and up E7 heads on the '86 shortblock.

Regardless, please, please, check the p to v clearence with those GT40 heads. They probably will not clear, definately will not with 1.7 RR's, and i'd really hate to see you guy's slap them on, then wreck the motor.
 
95, yeah, i misread your post. i thought that you said that the e7 was the only head to go on the 86 pistons.

thanks for the advice, i was under the impression that the 86 would accept all ford manufactured heads, not couting aluminum. s h i t
 
All Ford Windsor style heads, both factory and aftermarket cast and aluminum, will physically bolt on, so yes the '86 will ecept all Heads designed for a Windsor engine... The problem is that they have those pure flat top pistons with absolutely no valve relief in them. All '85 and older 302/5.o engines, and '87-up HO and truck engines had valve reliefs cut into the piston, so just about any head with a valve size under 2" would work with out any problems

The '86's used a head with a "fast burn" kidney shaped chamber design that sunk the valves deepr into the head compared to the traditional and conventional Wedge style chamber found in most other Windsor style heads. This allowed them to get away with no valve relief or dish in the piston to disrupt the flame front as it travelled across the chamber.