302 teardown and rebuild UK

[Ed McClements]

As mentioned in my build thread, I recently bought a '69 302 for rebuild:-

Which looks like a '68-style casting, but poured in March '69? Go easy on me if I've got this wrong! Aluminium tag is still in place, which makes me think it's not been apart, but what about these threaded gallery plugs...

which would have been pressed-in brass(?) plugs from the factory...right?

I made a start on disassembly today, and thought I'd share the gory details...we all like threads with pics, right? Carb, dizzy, fuel pump all came away very easily, after a coating of release fluid yesterday.

The waterpump has some crud, but next to no corrosion - the seller said that the coolant was fresh with green anti-freeze, and that the oil was clean. Take that for what it's worth, but so far the condition bears out this story.

Inlet manifold next; needed a hefty whack with an aluminium drift under the thermostat housing to unstick it from the heads, but it then came away cleanly.

The inlet faces on both heads seem not to have seen daylight for over 50 years; where the gasket came away with the manifold is a clean casting. Lifter valley seems in good shape, too - no baked-on oil or sludge yet.

And this the view from under the rocker covers...

Opinions welcome from anyone who has torn down one of these engines...does this look OK so far?

 

[Mike Pass]

From the block casting number it is a 1968 302 block from a Fairlane or Torino
C 1960s
8 1968
O Fairlane Torino
E Engineered component

Looks nice and clean so far. No sludge and gunk. Check bore size - standard is 4.000". Check mains and big end sizes. Have block crack tested at EDA before spending money. I hope it's a good one as they are getting hard to find in UK now. Cost to fully machine and prep the block for stroker is about £800 at EDA or Real Steel.

Cheers
Mike

 

[Mike Pass]

The screw in oilway plugs are a very good idea. The standard push in ones are steel and a disaster if they pop out.. EDA fit Allen screw-in plugs as a matter of course.
Cheers
Mike

 

[Chris]

Could be a handy thread for me! I too have nearly stripped one for a rebuild. I have no experience of smallblocks. All my previous engines are BB and my cobra has a 1964 427. Thankfully my 302 (68) looks to be in good nick, done little from a previous rebuild. It was taken out and replaced with a BMW by a previous owner who unfortunately suffered from demetia so I can't get any history and I have to take any previous work just as is. There are, as a result I guess, some odd things been done to the car. I did find 4 bent pushrods and a bent valve. No piston damage. I suspect it was over revved with cold oil maybe??
I popped off one big end cap and the bearings are good. I will strip it right back and probably add a top end kit. Existing heads are 68 standard but ported and with roller rockers. I was not going to stroke it. Should I???? Edelbrock top end kit??

 

[Ed McClements]

From the block casting number it is a 1968 302 block from a Fairlane or Torino
C 1960s
8 1968
O Fairlane Torino
E Engineered component

Looks nice and clean so far. No sludge and gunk. Check bore size - standard is 4.000". Check mains and big end sizes. Have block crack tested at EDA before spending money. I hope it's a good one as they are getting hard to find in UK now. Cost to fully machine and prep the block for stroker is about £800 at EDA or Real Steel.

Cheers
Mike

Hi Mike

Just need to beg or borrow a harmonic balancer puller (I have 2 and 3 leg pullers, bearing pullers etc but nothing that fits quite right) then I can get the timing cover off before diving into the bottom end. If the crank isn't scored and is close to stock size I'm sticking with a 3" stroke. I'm only aiming for modest power and torque and don't plan on a 331/347 build.

 

[Nick]

Looks very clean compared to what I found in mine

 

[Mike Pass]

Sorry Eddy but I don't have a harmonic balancer puller. Can you not rig one up with what you have and a length of studding?
At least your engine is pristine compared to Nick's crudfest!
Cheers
Mike

 

[Ed McClements]

Looks very clean compared to what I found in mine View attachment 111216

Looks like a prehistoric tar-pit, big enough to swallow a T-rex...!

 

[Neil]

Nick, did the previous owner of that engine ever change the oil or did he just keep adding more?

 

[Kevin Box]

Just a suggestion
Before you head down the track of overhauling your heads, price a complete set of new ones in cast or alloy depending on your preference.
Sometimes by the time you have machined the seats, machined the heads for new guides and replaced valves and spring etc, then new heads can be cheaper and they flow better right out of the box

cheers KB

 

[Ed McClements]

Just a suggestion
Before you head down the track of overhauling your heads, price a complete set of new ones in cast or alloy depending on your preference.
Sometimes by the time you have machined the seats, machined the heads for new guides and replaced valves and spring etc, then new heads can be cheaper and they flow better right out of the box

cheers KB

Thanks, Kevin. I like the look & originality of the iron heads, but the valves are small, and the exhaust ports are the size of postage stamps! Current favourite options are AFR165 or Edelbrock Performer heads. Or some bare Chinese castings checked and fitted with Manley valves, Comp springs and some good 1.6 roller rockers.
Choosing a cam seems harder than it ought to be...so many are advertised based on the idle sound, rather than lift, duration & overlap numbers. Performer RPM seems like the obvious choice, but am also looking at Comp Cams 282s, and will be taking advice from the experts on cam selection.

 

[Nick]

Hi Mike

Just need to beg or borrow a harmonic balancer puller (I have 2 and 3 leg pullers, bearing pullers etc but nothing that fits quite right) then I can get the timing cover off before diving into the bottom end. If the crank isn't scored and is close to stock size I'm sticking with a 3" stroke. I'm only aiming for modest power and torque and don't plan on a 331/347 build.

Hi Eddy, this is the only puller I have so must be the one I used. If it is of any use you are more than welcome to borrow it.

 

[Ed McClements]

Hi Eddy, this is the only puller I have so must be the one I used. If it is of any use you are more than welcome to borrow it.

Y'know, Nick...I have just such a thing in the bottom of the roller drawers somewhere. The side links are a bit stretched, after trying to use it on a Ducati primary gear a few years back. They sit on a taper, with no key, and transmit 130-off horsepower. Needless to say the nut holding it on it torqued to F.tight, and the taper gets quite a grip on the gear. Eventually I borrowed a hydraulic puller, tightened it right up (keeping the nut on the shaft a couple of threads!) and gave it a tap with a hammer to shock it free. Damn thing went off like a shotgun shell.

 

[Nick]

Y'know, Nick...I have just such a thing in the bottom of the roller drawers somewhere. The side links are a bit stretched, after trying to use it on a Ducati primary gear a few years back. They sit on a taper, with no key, and transmit 130-off horsepower. Needless to say the nut holding it on it torqued to F.tight, and the taper gets quite a grip on the gear. Eventually I borrowed a hydraulic puller, tightened it right up (keeping the nut on the shaft a couple of threads!) and gave it a tap with a hammer to shock it free. Damn thing went off like a shotgun shell.

It was around 13 years ago I took it off, so memories are a bit hazy, fairly certain it also needed some fine tuning / tapping with a hammer (probably 4lb lump knowing me). Having said that, and only ever rebuilt 2 engines, I remember being surprised at how easily the engine came apart especially removing the heads from the block.

 

[Mike Pass]

Any good?

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Cheers
Mike

 

[Ed McClements]

I popped out to the garage to take another look earlier, and found amongst my odd fabricated tools a thick ally plate with 3 holes drilled in strategic positions for pulling a Triumph crank back into the main bearings - this did the job nicely with a large centre bolt. Didn't need much pressure at all, compared with some gears & bearings I've had to pull.
While I was there I lifted the first head for a look; this is what I found once I'd wiped the crud from the top of one piston with some carb cleaner:-

All four cylinders on this bank look the same - small lip at the top of the cylinder, some carbon build-up on the pistons, stock bores and as far as I can see, OEM pistons.

This the (unworn) part of the cylinder, above the lip - I'll try and get a reading on the worn part later with a telescopic bore gauge and a micrometer, though it's largely academic since this looks like a candidate for a +.030 rebore so far.

I think what I'm seeing here is some leakage from coolant passages into the pushrod holes / lifter valley area

Same on all coolant holes:-

Seems to be no untoward effects, other than a sludge build-up has come into contact with the heat and oil in the lifter valley. At least, that's what it looks like to my untrained eye.

And all the combustion chambers look like this - carbon deposits, 58cc (?) chambers, small valves.

 

[Randy V]

Aye, she was an oil pumper!
Betting on substantial taper in those cylinders. I’ve had bores cleaned up at .010” in case you’re looking to preserve the block for future rebuilds.
Valves and guides are going to definitely be required. Sometimes you can get by with knurling the guides and honing to size for new valves.
Or
You can get some pretty nice aftermarket heads fairly inexpensively - I installed a set of Procomp heads on my recent 331 build. Once guide plates and rocker studs were purchased, I was right around $600 USD.

 

[Jac Mac]

Could be a handy thread for me! I too have nearly stripped one for a rebuild. I have no experience of smallblocks. All my previous engines are BB and my cobra has a 1964 427. Thankfully my 302 (68) looks to be in good nick, done little from a previous rebuild. It was taken out and replaced with a BMW by a previous owner who unfortunately suffered from demetia so I can't get any history and I have to take any previous work just as is. There are, as a result I guess, some odd things been done to the car. I did find 4 bent pushrods and a bent valve. No piston damage. I suspect it was over revved with cold oil maybe??
I popped off one big end cap and the bearings are good. I will strip it right back and probably add a top end kit. Existing heads are 68 standard but ported and with roller rockers. I was not going to stroke it. Should I???? Edelbrock top end kit??

Dont stroke it unless you have to.If it needs a rebore dont bore straight to 0.030 unless you have to. Measure the deck heights at all 4 ends, if deck surfaces are good you can build a nice 302 combo by swapping to 289 rods, you might need to skim the piston crowns to obtain 0.040 piston to head clearance and flycut the valve notches to accomodate your cam of choice. The alloy heads have merit as they address the valve seat wear problems. Make sure you drill pistons for pin oil & cut lube groove in lifter bores. Get whoever is doing the block machine work to install the new cam bearings in a manner that they become restrictors. If you decide to re-use those heads use Chev SB valves , 1.5" exh & 1.9" inlets. Yella Terra and some others make a nice paired shaft roller rocker system that does not require as much maintenance as the individual stud setup and does not need guide plates and fits under most std rocker covers.

 

[Bill Kearley]

It's not a good idea to pull on the OD of the damper if you plan on reusing it. You should pull on the pully mount holes !!!!!

 

[Chris]

Dont stroke it unless you have to.If it needs a rebore dont bore straight to 0.030 unless you have to. Measure the deck heights at all 4 ends, if deck surfaces are good you can build a nice 302 combo by swapping to 289 rods, you might need to skim the piston crowns to obtain 0.040 piston to head clearance and flycut the valve notches to accomodate your cam of choice. The alloy heads have merit as they address the valve seat wear problems. Make sure you drill pistons for pin oil & cut lube groove in lifter bores. Get whoever is doing the block machine work to install the new cam bearings in a manner that they become restrictors. If you decide to re-use those heads use Chev SB valves , 1.5" exh & 1.9" inlets. Yella Terra and some others make a nice paired shaft roller rocker system that does not require as much maintenance as the individual stud setup and does not need guide plates and fits under most std rocker covers.

Sounds like you know these engines! Thank you for the advice. Will explore