302 teardown and rebuild UK

Kevin Box

Supporter
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.
Got a 351W with 6.58 rods in my workshop - narrowed 400M rods, Cleveland bearings, Pin bore sleeved to .927, KB276 pistons. Converted to Hydraulic roller, Edelbrock E205 heads 2.08"/1.6"

cheers KB
 
Got a 351W with 6.58 rods in my workshop - narrowed 400M rods, Cleveland bearings, Pin bore sleeved to .927, KB276 pistons. Converted to Hydraulic roller, Edelbrock E205 heads 2.08"/1.6"

cheers KB
What does it run like Kevin, I built a 351w Block, 400 crank, 6.58 rod SVO Nascar Cleveland head version many years ago, Torque Monster, progressively broke every thing in the driveline before it ripped the whole crank/ main web assy out of the block.
 

Eddy McClements

Supporter
Eddy, if all the bearings and crank journals look like that, have the crank re-ground to the nearest undersize, chamfer the oil holes, and polish the journals. I replaced the Clevite 77 bearings in my 383 Donovan with King pMax Black XP rod and main bearings when I tore it down the last time. I recommend them.

Thanks for the heads-up, Neil. I'll look into those.
 

Eddy McClements

Supporter
Mains out....someone sure had their money's-worth out of these bearings!

Lowers:-






Uppers:-






I can see the contamination still embedded in the soft bearing metals; it's amazing what good condition the crank is in, considering the abrasion it must have been suffering from all this junk. Crank pics next.
 

Eddy McClements

Supporter
My bad....it's cam pics first.

Couple of the lobes have this odd wear which I've not seen before...






This is the matching lifter...any trace of a crown on the lifter face is long since gone, though it's clearly still been rotating in its bore and scribing-out two concentric circles...

 
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Randy V

Admin
Lifetime Supporter
Yeah - that cam has seen its last engine - hopefully. I have seen this before with engines that sit and have their ventilation systems open to the atmosphere. My best advise is to use a roller cam and conversion kit going forward. The lack of zinc / proper lubricants is causing the demise of camshafts around the globe..
 

Mike Pass

Supporter
Usual cam scuffing on flat tappet cam. When catalytic converters came in they dropped the ZDDP content of oils to save the cats. Many did this without informing the customers. I used to use Valvoline VR1 but they dropped the ZDDP levels. You have to check the ZDDP level in the oil you are using if you have a flat tappet cam. Lucas Racing Oil and Joe Gibbs Racing have good levels of ZDDP. There is a website which has tested most oils for ultimate fail load and ZDDP levels etc. Guess which oils came out on top. I use the Lucas Racing Oil as suggested by Kenny Coleman. When you rebuild the motor fit a roller cam as advised by Randy. No scuffing or tedious cam break in procedure and any good oil will do.
Chances are the previous owner used the wrong oil with too low a level of ZDDP and it ate the cam - sending powdered metal all round the engine with the results you see. Very thorough cleaning needed. Just for fun measure the height of the cam lobes! I did a Ford 1,700cc crossflow recently which would not run smoothly. When we checked it out every lobe was a different height.
Cheers
Mike
 
Your new full engine gasket set will likely have a two piece rubber rear main seal, when you remove the existing rear main seal its very likely the pin will still be in place in the rear main cap, you MUST remove that when you use a two piece rubber rear main seal. The two piece seal should also be fitted to the cap & block in a 'one up ,one down' fashion to align the seal ends
 

Eddy McClements

Supporter
Your new full engine gasket set will likely have a two piece rubber rear main seal, when you remove the existing rear main seal its very likely the pin will still be in place in the rear main cap, you MUST remove that when you use a two piece rubber rear main seal. The two piece seal should also be fitted to the cap & block in a 'one up ,one down' fashion to align the seal ends
Thanks for the heads-up. Is it worth having it modified for one-piece seal when I take the block & crank for machining? And any recommendations for a good compromise of price vs. quality on 302 gasket sets? On my water-cooled Ducatis, the factory changed from composite head gaskets (with crimped fire ring) to a multi-layer-metal style with much improved sealing (and smaller squish / quench). To get the squish band to 0.8mm you change the cylinder base aluminium gasket / shim. I think these MLM gaskets are available for Ford small-block, too?
 
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Eddy McClements

Supporter
Crank pics and measurements...





And the scores on the doors (those of a metric indisposition should look away now...!)...

All mains are at 57.11mm = 2.248"




And all rod journals are at 53.92mm = 2.123"




That's the end of the main dismantling, and it's been a relief to find a 50-y-o engine that's a sound base for a rebuild. I can't believe how good the crank is, given the state of the sludge in the bottom of the sump, the bearing shells and the dead cam.


Edited to add:-

The distance between crank webs at #3 bearing (where the thrust bearing lives) measures at 1.139" using a sprung-loaded bore gauge and the mic. Bit fiddly to do; what should the dimension be at this point?
 
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For MLS head gaskets Cometec have the widest choice of compressed thicknesses ( .027 to .080 I think). FelPro or Mahle are good for the rest and you can upgrade to a Viton rear main. The rubber one piece sump and valve cover gaskets are also worthwhile as they are reusable and contain small metal bushes to prevent distortion from over tightening. Ditch the umbrella valve seals for Vitons.
 
Crank pics and measurements...





And the scores on the doors (those of a metric indisposition should look away now...!)...

All mains are at 57.11mm = 2.248"




And all rod journals are at 53.92mm = 2.123"




That's the end of the main dismantling, and it's been a relief to find a 50-y-o engine that's a sound base for a rebuild. I can't believe how good the crank is, given the state of the sludge in the bottom of the sump, the bearing shells and the dead cam.


Edited to add:-

The distance between crank webs at #3 bearing (where the thrust bearing lives) measures at 1.139" using a sprung-loaded bore gauge and the mic. Bit fiddly to do; what should the dimension be at this point?
You measured that @ .011 " back in post #34 with the worn bearngs, Should be good to go with new stuff since factory setting is 0.004'' to 0.008". If any wear it will be on rear thrust face of crank since it sees most of the load from clutch or torque converter. many autos seem to have more of a wear problem at that point, often caused by wear on pump drive tangs/flats.
 

Randy V

Admin
Lifetime Supporter
When I prep crankshafts, I do all my machining (chamferring oil holes mainly) before I have the crank pins turned and polished to the next undersize. That way if any slips of the rotary stone, the damage will be ground away when the crankshaft is turned.
 

Eddy McClements

Supporter
Quick update:-

I have found a nearby machine shop (just an hour away and still within Lancashire) stuffed full of Sunnen, Serdi and other top-notch equipment, plus an engine guy who knows what he's doing. In addition to the Jag E-type race engines (which are their mainstay) Daimler 250 V8, Rover V8, MGB and other period Brit stuff, there were a couple of 302s and a 351 with Scat stroker crank (I guess a 408?) being built for a Pantera. I paid a COVID-safe visit and was given a good hour and half of time and good advice before leaving my crank and block for crack detection, measurement and machining.
Further updates to follow as progress is made.
 

Jim Rosenthal

Supporter
Two suggestions: first, another advantage of alloy heads is that the reduce weight above the cars roll center- this is probably more important in a front-engine car such as a Cobra, but shedding weight in high-performance cars is always a good thing. Second, I think you are on the right track with your goals in this engine build. In light cars such as GT40s and Cobras, you don't need a wild and peaky motor to give you excellent performance. The SNF engine in my Cobra came (despite my instructions) with a bracket-racing cam which was entirely too aggressive. We took it out and replaced it with a Comp Cams Hi-Energy grind, flat lifter hydraulic, which transformed the engine completely. Nice power, decent idle and a broad torque curve that made the car a joy to drive. For my modest driving skills and advanced years, I don't need a beast of an engine to make this kind of car fun to drive.

If you are going to look at alloy heads, look at AFRs. Over here, they are a crowd favorite for all sorts of reason- peerless quality, very acccurate machining, and great performance. I have AFR 185s on my GT40s engine, shortly to be moved to a new block. (see thread)
 
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