302 engine block comparison pictures December 08, 2010, 08:49:07 PM Though this is not a subject often discussed on this board, it often brought up on other sites. Due to our new upgraded features, posting pics here is a breeze! Just limited to three pics per post.Pics aren't perfect, but it gives a good idea of each block.Here are a series of three posts showing three different 302 engine blocks: The first series of three is a late model roller block, second series is early 289/302 block, third in the series is a Mexican block.Areas to note on a late model roller is the size of the main cap and webbing area beneath the main (can be easily seen in two of the shots of the #2 main). Quote Selected
302 engine block comparison pictures Reply #1 – December 08, 2010, 08:55:40 PM This is the 289/302 block Quote Selected
302 engine block comparison pictures Reply #2 – December 08, 2010, 09:03:25 PM Mexican block. Difference between the early 289/302 are obviously the main caps. All these older blocks have more material in the main web area and have "blind" holes for the main bolts/studs and head bolt/studs (late model blocks have the holes drilled all the way through, this is where the block begins to split when you put a lot of power to them). Quote Selected
302 engine block comparison pictures Reply #3 – December 09, 2010, 11:59:26 PM Cool. This should be a sticky. Quote Selected
302 engine block comparison pictures Reply #4 – December 10, 2010, 07:24:26 AM Good info, I've seen the term Mexican block used a lot but never knew the difference. Quote Selected
302 engine block comparison pictures Reply #5 – December 10, 2010, 01:44:15 PM I've heard the iron content of the Mex blocks wasn't as good as US which is the reason the caps are larger, could be a rumor I've never checked... Unless it's a HI-Po 289 or Boss 302 which are desired by the restorers, I'd never consider anything but a roller block for a "modern build"... Quote Selected
302 engine block comparison pictures Reply #6 – December 10, 2010, 08:03:17 PM Quote from: TurboCoupe50;345201I've heard the iron content of the Mex blocks wasn't as good as US which is the reason the caps are larger, could be a rumor I've never checked... Unless it's a HI-Po 289 or Boss 302 which are desired by the restorers, I'd never consider anything but a roller block for a "modern build"... If you keep the power level and/or the RPM low, a roller block is fine. Raise the power level and/or RPM, you often end up with a block in two pieces.Due to the thicker main webbing and the blind main bolt holes, the early blocks have less tendency to split, offering the ability to take more power and RPM. Use of a roller cam in an early block requires link-bar lifters. In all of my research, the quality of the Mexican blocks casting has not been a question. Rumors of higher nickel content in Mexican blocks in common, but is commonly dismissed by those in the know. The blocks are generally percieved as equal in quality and strength of the early 289/302 US made units. The advantage to a Mexican block is the extra support offered by the sturdier main caps. Quote Selected
302 engine block comparison pictures Reply #7 – December 11, 2010, 01:08:04 PM A lot of people say that "500 hp is the most a roller block can take" which is not really true. It depends on the tune/rpm more than the power level. If you're going to build a 700 hp 302 with a blower spend the extra money and get a BOSS block with 4 bolt mains. Then you only have to build in once . Quote Selected
302 engine block comparison pictures Reply #8 – December 11, 2010, 04:25:59 PM Quote from: thunderjet302;345287A lot of people say that "500 hp is the most a roller block can take" which is not really true. It depends on the tune/rpm more than the power level. If you're going to build a 700 hp 302 with a blower spend the extra money and get a BOSS block with 4 bolt mains. Then you only have to build in once . Absolutely right. There is no one number which will break a roller block. Stress on engine blocks varies depending upon how the power produced. A high HP 8.2 deck motor natually aspirated will typically take 7,000+ RPM to make that power. Nitrous has instant and massive torque that can play havoc with any block, depending on the size of the shot. Supercharging introduces the variable of pulling the nose of the crank with the belt, introducing side loading on the crank. Turbos can be less demanding on a block, due to (potentially) lower RPM, smooth ramp up of boost and no side loading on the crank. If the tune is off in any combination (N/A or power adder) and detonation takes place, things will break...Putting a lot of power to stock block is never a problem. That is, unless it breaks and it's your's!:toilet:There is no doubt an early or mexican block is sturdier than a roller. How much? Hard to say, lots of opinions out there. It's a step up.There is, absolutely no comparison between an early or mexican block and an aftermarket block. Maybe someone has pics of an aftermarket block which could be added here. Quote Selected
302 engine block comparison pictures Reply #9 – December 12, 2010, 04:08:47 PM If its high rpm and big hp you seek then:http://www.dartheads.com/products/engine-blocks/ford-small-blocks/shp-ford-small-blocks.htmlHold on to your wallet though.Darren Quote Selected
302 engine block comparison pictures Reply #10 – December 12, 2010, 06:18:45 PM Darren, thanks for the link.When folks ponder a powerful build up, cost considerations are always a factor. The one most seem to miss though is the amount of money it takes to get a block properly machined for performance use. Cleaning, checking, boring, decking, line honing all add considerably to the cost any stock block. Be it a roller, early or Mexican, the costs are the same. In my experience it may run $800 to $1,200. Kind of makes a free block (or $300 - the current going rate on a "raw" Mexican) less appealing. Or course the Dart block will also require some machine work (the bores need to be finished), but when its all said & done, the cost differential may not be as great as it first appears.That being said, all of blocks shown are mine and I still haven't sprung for aftermarket block! It's just so much harder to take the pain all at once. Kind of like putting a frog in boiling water, he'll jump right out, but put him in a cool pan and gradually raise the heat, he'll be cooked! Quote Selected
302 engine block comparison pictures Reply #11 – January 07, 2011, 01:12:46 PM FWIW the mexi 302's had rail mount rockers my cousin has a 60's fairlaine with a mexi 302 in it from what i hear the heads are very desireable. Quote Selected
302 engine block comparison pictures Reply #12 – January 07, 2011, 01:48:52 PM I wouldn't waste time on a set of 60's factory Ford Windsor heads. Modern heads will beat the old stuff all the time no matter how much you port the stock 60's heads. Quote Selected
302 engine block comparison pictures Reply #13 – January 07, 2011, 02:58:48 PM Quote from: thunderjet302;348750I wouldn't waste time on a set of 60's factory Ford Windsor heads. Modern heads will beat the old stuff all the time no matter how much you port the stock 60's heads.I would take 69-70 351 heads over E-6 or 7's any day. Not thrilled with the push in studs, but that can be fixed. Quote Selected
302 engine block comparison pictures Reply #14 – January 07, 2011, 03:11:23 PM Quote from: 86T-bird;345308Absolutely right. Putting a lot of power to stock block is never a problem. That is, unless it breaks and it's your's!:toilet:It sorta sucks more when you break it and it belongs to your buddy. Quote Selected
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