According to my DIY checks, they're on the high side of the range @ 65-66cc. It seems more likely to be 66. The one time I got 65cc, there was probably a CC leftover in the spark plug from the previous test. That was over several tests on only one head, but just using syringes, and not a proper burette.

Having them milled more isn't a big deal. According to what I've been reading, a .020" mill will knock off about 3cc, or approx .007" for every 1cc. I've read on the Mustang forums where guys measured the GT40's at 65cc, milled them .020" and measured at 62cc. No idea if this is correct...just what I've been reading.

I'll wait and see what the engine shop says, and what their CC test shows. I just wanted to check 'em on my own for information. With my stock pistons, a 62cc chambered head should put me around 9:1 compression, according to the calculator linked below.

Compression Ratio Calculator

 

There will be a chance you can use the stock pushrods and have your valve lash work out ok. If you mill the heads that might be out the window unless your machine shop guy grinds the tips of the of the valves and can get it in spec.

I seem to remember one of the cam companies had a adjustable setup for the later heads. I believe it was a stud that went into the hole were the bolt goes, and under the stud a plastic coated guide plate was used to guide the stock pushrod. Then you used the stock rocker arms and a locking nut to adjust the lash. I might look and see if I can find it.

 

That was easy. Here it is.

https://www.summitracing.com/search/...kits/make/ford

 

Did/does your 302 have these doodads? Temperature-actuated vacuum control valves:




My M-block 400 had 2 or 3 of them.

My point is, look on your water pump and see if it has a place to screw in such a doodad - assuming you "ripped out the emissions crap" or for some other reason removed that stuff AND your OEM configuration had one of those things in the water pump.

~~

What I did on my old Tempo with a 2.3L 4-banger... someplace in the block's water jacket was where the factory-provided sensor screwed in... I did what people will tell you to not do, I installed a tee and connected two switches/senders to it.






I hand-drew something that kinda-sorta reflects what I'm walking about... basically, I screwed an "extension tube" into the side of the engine where the factory idiot-light sender was. I don't know where I got that thing, it was maybe 2" long with a male NPT thread to screw into the engine and a female NPT thread to accept the other sender.

The aftermarket gauge's probe didn't quite extend into the water flow like I'd like it to, and the factory sender was certainly "out of the flow" but I decided to try it, anyway, my thoughts being the two devices will eventually reach the same temperature as the water flow but it'll just take some more time.

I never really noticed a difference in how long it took the gauge to react - as compared to when I had only the aftermarket gauge probe installed and the idiot light was entirely disconnected... I didn't like having the idiot light disconnected, sometimes a red light on the dash attracts more attention than a needle on a gauge.

I have no idea where I got that hex tube extension thing, I think I got it from my father's garage someplace.

 

Franklin2,

Thanks for the link. Those kits look like they convert the pedestal mount heads to a stud for use with adjustable roller rockers ya? Not for use with the stock stamped steel rocker arms.

I'll talk to the engine shop. I'll be stopping in there early next week. I was really hoping to keep this thing simple, so we'll see. According to what I've read on the mustang boards (seems 90% of "302" searches end up there), they all use the rocker shims if the heads are milled any amount.

https://www.summitracing.com/int/par...a302/overview/

 

Thanks ctubutis, I may give that a try. It's not urgent as I won't be getting to firing this thing up for a couple months yet if all goes well. I did have some of those temp controlled doodads in the stock manifold, but I'll have a look at my new Edelbrock again tomorrow and see if there are any extra ports. I thought not, but I will look again.

 

The Edelbrock Performer SBF intakes have 2 threaded ports in the intake coolant crossover. And an additional boss cast in the cross over that could be drilled and pipe tapped for a third port..
Also many thermostat housings have a threaded port. All the aftermarket replacements have them.
So you will have lots of options for adding another coolant sensor with out having to do anything strange.

Keep the factory temp gauge it is a good back up, and is located in line of sight. I always have noticed the factory one climbing first before the aftermarket one. You can then check the aftermarket one to see what is going on. Personally I do not like dead gauges in the gauge cluster either but that is me.

As for the sensor use what ever funds allow. They are pretty bullet proof ,even the cheap ones, they either work or they don't.

 

IIRC I had 2 in the thermostat housing and 1 in the water pump. But that's my M-block, your Windsor is surely different.

 

Some good news today...I think.

Borrowed a set of telecoping gages from work to check my 302 bore sizes, and the bores are all showing between 4.0005" and 4.001" which I assume is good.

I found some comments online indicating that the stock 302 bore tolerance is between 4.0004" and 4.0048" not sure if that is accurate or not.

Might save me a few bucks if the thing just needs a hone job.

 

Not boring the block will save major bucks. Around my area it is at least $80 per hole to bore, and then you have to buy new pistons, and pay to have someone put them on the old rods. It starts adding up.

 

Don't surface the heads if you do not have to.
If you do need to , .010 is okay, .020, and especially above that you might start having intake manifold fitment problems.

 

It is not so much bore diameter but piston skirt to bore clearance. If it exceeds 0.007" you should rebore and replace the pistons. Given that your engine is still basically the stock bore (indicated by the still showing cross hatching) you likely just need a re cross hatch for ring seating and to brighten up the bore and reuse the stock pistons.


If you deck the heads for every 0.010" Milled from the heads/block you should mill the head side of the intake 0.010" and the Bottom or block side of the intake 0.0143"

Generally you can getaway with a 0.010" ish cut from the heads/ block and not have to mill the intake. Anything more than that and you should mill the intake.
If you mill the intake stamp the under side of the intake indicating how much has been cut from the gasket surfaces.

 

Thanks for the replies gents,

Good to know on the piston skirt to bore clearance. I was just checking for curiosity sake. I'm leaving the pistons and crank in the block as-is and will let the engine shop remove them. I've removed everything else so far. Pulled the oil pan this morning, dipstick tube, motor mounts, timing chain and gears, lifters, etc. Got it all cleaned up about as good as it's going to get for now.

I'm hoping for just a hone and re-ring.

Not sure on what/how much milling will take place yet. I guess I'd like to be around 9:1 CR, and I'll wait and see what the engine shop recommends to get there. I checked the piston depth yesterday, and at TDC, they're 0.014" from the deck.

 

As stands with the stock pistons and bore and stoke and 65CC chambers you should be about 9:1-9.4:1 with a 0.21" compressed head gasket thickness.

If you CC the valve reliefs in the piston I can get it closer.

 

His stock heads were 78cc or something close to that correct? And it was around 8.5 to 1 stock? These new heads are in the mid 60's cc? So that is why he is seeing a increase in compression ratio by just putting those heads on? Just trying to clarify it for him, since I think he thought he was going to have to mill those heads.