302 teardown and rebuild UK

Several reasons, a longer rod improves the rod length to stroke ratio, 302 is 5.090" while 289 is 5.155, less pressure on piston skirts and cylinder walls. In this example it changes the rod ratio from 1.696 to 1 to 1.718 to 1, It also 'parks' the piston closer to TDC and helps build cylinder pressure after the ignition flame front starts. Normally during a rebuild the builder would pre-assemble the short block and measure the distance from deck surface to top of piston at TDC, then get the block deck surfaces machined to get the piston to match deck heights, for the likes of your engine if the block surfaces are in good condition and relatively square & very close on deck height measurements you can simply machine the pistons to match the block height and save your self the expense of machining the block. Similar gains can be had with a 289, but in that case you use a 302 crank and keep the 289 rods. Can explore lots of other combo's like reworked chev rods and stroker pistons etc if you have access to lath, machine shop etc.
 

Eddy McClements

Supporter
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 !!!!!
Yes - I should have taken a photo, but I bolted the ally plate to the damper using the three ³/8 pulley holes and ran a large bolt down the centre to press on the (loosened) damper mounting bolt. Came off very easily.
 

Eddy McClements

Supporter
Further photos, once the other head was lifted and timing cover removed...an odd clean patch on the top of piston #7...



This is the worst cylinder, #8 - there's a tide mark where think there's been water allowed to get in and settle:-



The timing chain was absolutely on its last legs...almost slack enough to jump a tooth, and there must have been 20 degrees of free play on the cam!





There's a hard plastic outer ring on the cam sprocket, which has broken away in chunks. There are also some broken-up hard plastic(?) pieces littering the rocker area - I'm pretty sure these are the remains of the old-style stem seals, which have hardened and shattered over the years.

I dropped the sump / oil pan - nothing too scary in there. Oil is a little milky and there was a lot of grey sludge in the very bottom, but nothing shiny and no hard items. Just 50 years of worn-away bearings / pistons / cylinder walls, I guess! I'll try and get a look at the crank tonight.

Thanks for all the responses and suggestions.
 
That timing chain is scary looking. Not much material left on the teeth there. im guessing the chain rollers and pins are equally as worn.
 

Randy V

Staff member
Admin
Lifetime Supporter
Timing chain / sprockets look quite typical. I’ve pulled apart a number that look just like it.
The nylon covering on the cam sprocket was to reduce engine noises.
 

Neil

Supporter
Eddy, Cloyes offers a whole timing chain kit that is top-notch. It has the roller chain, cam sprocket, and crank sprocket. By replacing everything in a matched set you get a good tight-fitting replacement.
 

Mike Pass

Supporter
Apologies for the thread drift but there is a 1974 302 engine on Ebay now at £300. Says collection from Sevenoaks Kent. May be of interest to someone on here,
Cheers
Mike
 

Kevin Box

Supporter
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
Eddy

Cam choice is not that hard if you do it right
the essentials are
1 Get your head around what you want the engine to do - is it something that you can easily handle in traffic with the odd track visit or is it a hill climb and track special?

2 The decision you make in #1 will determine what head modifications and base casting you use.

3 Make sure you are not fooling yourself with the decisions in 1 & 2

4 Once all the head mods are complete and you have a set of flow figures for your heads talk to a cam manufacturer or cam grinding service to get the best option for your combination - go with a Hydraulic roller conversion It will save you a lot of headaches in oil choices, lash adjusting, rocker noise to name a few. Also going with a roller cam gives you better area under the curve with not so much duration - better drivability Make sure your valves springs and retainers are up to what the cam grinder recommends and don't compromise on roller rockers.

Once you get that far in your choices you should be OK the worst mistake you can make is have an engine that is to wild for their needs. it will be just a pig to drive


Hope this all helps

regards

KB
 

Kevin Box

Supporter
JacMac rather than using 289 rods, aftermarket 400 Chev rods (5.565") are the go with 3.25" SBF stroker pistons (1.175) (also KB 276 Hypereutectic ) with .927 pin
A bit of mucking around to make the big ends work with two choices available
First option narrow the big end of the rod and use Chev V6 bearing (crank ground to Chev Diameter)
Second option is resize the Chev big end to SBF bearing dimension.
Base issue is the Chev rod is too wide

Another option is to use 5.4' rods with a 1.3" pin height pistons. I think the piston to use is one of the 351 Stroker pistons

Cheers KB
 
JacMac rather than using 289 rods, aftermarket 400 Chev rods (5.565") are the go with 3.25" SBF stroker pistons (1.175) (also KB 276 Hypereutectic ) with .927 pin
A bit of mucking around to make the big ends work with two choices available
First option narrow the big end of the rod and use Chev V6 bearing (crank ground to Chev Diameter)
Second option is resize the Chev big end to SBF bearing dimension.
Base issue is the Chev rod is too wide

Another option is to use 5.4' rods with a 1.3" pin height pistons. I think the piston to use is one of the 351 Stroker pistons

Cheers KB
Yes, there is/are heaps of options out there now for 289-302-351w. One Ive got a guy interested in at moment is a 351w, but with 6.58'' rods , 1,18" pin height pistons from the 331 stroker and the 351 crank. ( 272 Y-block se bush's push straight in for floated pin, all done. Interesting thing is his current engine is a plain jane 351w with the 6.03" rods from a 302 Aussie Cleveland as we have discussed before. He had it on a rolling Dyno locally & the Dyno operater asked how big it was, told him 351 and got into a bit of an argument, Dyno guy reckoned it was strongest 351w had ever had on board and that included all the 400 plus strokers he had seen.
 

Eddy McClements

Supporter
@jac mac @kevinruthbox Thanks for your suggestions, which I am (slowly!) digesting. I did have a chat with the machine shop earlier in the year when I took them my first block (scrap) and their first response was "Stroke it to 347...a lovely engine...you need more torque...torque is speed".
Thing is, I am running a Renault UN-1 transmission and I want it to live a long & happy life. I don't want to build a stroked engine - I want to build something which:-
has about 325-340 horsepower
will stay in one piece
will rev up to 6k (ish)*
will not require replacement of perfectly serviceable parts - ie. if the 302 crank is good I wish to use it

It seems to be an uphill struggle, in the UK** at least, to persuade a machine shop to think outside the box...go a bit "off-piste" and try something unfamiliar. If their work is all stock rebuilds / restorations or stroker kits I can understand why they might be averse to someone unfamiliar walking in the door and announcing he wants to build a long-rod 302 with Chev valves & con-rods.

If the '69 heads with 1.9" & 1.5" valves and some bowl/throat work will flow sufficient air to make this much power I'd be happy to use them.

Didn't have much time at the weekend for the workshop, but I did get a dial gauge on the crank...



and measured 0.30mm (about 0.011") end-float, which seems encouraging for a 50-year-old engine.


*The car will be built for road use, with occasional track day. Sometimes it's useful to be able to hang on to a gear between turns, so I don't want the engine to hit a brick wall at 5200...be preferable if it'd keep going past that

**I'm guessing, but I reckon the bulk of UK engine work will be BL A-series, Ford Kent crossflows, MGB and Jaguar - it seems that there are (relatively) few places with good expertise in US-derived V8s?
 

Eddy McClements

Supporter
Didn't have much time at the weekend for the workshop, but I did get a dial gauge on the crank...
and measured 0.30mm (about 0.011") end-float, which seems encouraging for a 50-year-old engine.
I should add...of course I'm going to remove / check crank and have it ground & replace all bearings. Just out of academic interest I thought I'd see how worn-out it is beforehand.
 
I should add...of course I'm going to remove / check crank and have it ground & replace all bearings. Just out of academic interest I thought I'd see how worn-out it is beforehand.
To put it somewhat bluntly, If your machine shop seems unwilling to think along those terms and wants to take the stroker route instead you need another machine shop, what Kevin & I have suggested is not 'new', Ford-Shelby et all were thinking along these lines 50 years ago, the ~380 horse engines back then were using 289 & 302 cranks with 5.315 rods ( these are still available from scat etc ) Yes they or Gurney ventured down the stroker route, but the GT40 results tend to show more DNF's with those experiments. We are spoilt for choice now . Mike Huddart is/was in the UK somewhere, seemed to know his way around SBF stuff, must be others. Ive built a few strokers, only one I feel comfortable is the 3.25" version, the longer 3.4" one is more suited to drag racers etc. Short duration running.
 
People seem fixated on stroking engines but why? These cars are faster than most will ever need and all stroking will do is force you to buy a stronger gearbox to cope with it. That`s just my opinion and why I`m building a 302 size 302 again.
 
Just seen Mike Huddart mentioned but unfortunately he has retired and sold his equipment. Really bad timing just when I need him to work on mine.
 
Those '69 heads are the main impediment to achieving your horsepower goal and although money/labour can fix that, perhaps it would be better to start from a better place, the obvious choice being an aly head such as the AFR 165. If you want to stay with iron heads then there are some better Ford production heads such as the GT40/Gt40p as fitted to mid range trucks in the 80's which can flow 25 or 30% better than the 289/302 head like yours. Might take a bit of time to find in the UK but I can't see anyone asking more than a couple of hundred £ for them.
 
Top