It's time to build me a new engine! I've been gathering up parts, and so far here's what i've got: Forged crank/rods/11:1 pistons for a 302 Stage II Ported TFS Twisted Wedge heads Solid roller cam ~.575 lift ~240 duration (haven't gotten this one yet, so feel free to make recommendations!). So i'm thinking that i'm probably going to wrap this one up to about 7,000 rpms before i think about shifting. I'm not in the income bracket to buy a motorsport or dart block, so i've been thinking about hunting down a mexican block. I've heard the other 302 blocks can't handle this kind of RPM without twisting? What years/cars/trucks am i most likely to find these motors in? Does anyone have any other recommendations? Would a main girdle be enough for any other 302? And finally, i've read that they have an external boss on the driver's side of cylinders, where is it located? I found one guy who has a mexican block for sale, but it needs to go .040 over and my pistons are .030
I've got one out in my parts shed, out of a 74 pick-up. "Knobs" are on the front of the block about the same height as the water inlet holes.Theres a lot of arguement about the strength of this block over that of the regular 302 block, and after talking to a couple of people who have blown the main webs out of them and the guy that does the machine work on our modified circle track engines, they are about the same as the early( pre74) blocks.They do have the wide main caps like a 289 hipo though. Most of the time all a girdle does is save the crank & rods when you break the main webs out of the block, but they are cheap insurance-just be sure and have the mains align honed with the girdle installed.
of course this is just my opinion, but you said a 302. i know there are some issues with the 302 block with stroker kits, but have never had a problem with a 289-302 built more for rpm than torque. main studs, line hone, maybe a girdle, good rod bolts and rod prep will always help keep the bottom end together. finding a boss 302 block would help. i had a nice boss 302 track engine ran down into the tens at 9500 rpm. main studs and good engine prep.
Here's my opinion, FWIW. I wouldn't use just any 11:1 compression pistons when you can get a set of SRP 13.8:1's for about the same price...and they're a ton lighter than the usual TRW L2249's. With that, you'll be able to run more camshaft, in the 250 @ .050" and .650 lift range with those heads. Also, it might be a good idea if you plan on spinning it that high to get a set of GOOD aftermarket rods, Eagle, Scat, Lunati, etc. Summit has a nice set of H beam rods w/7/16" bolts for a pretty good price. The mexican blocks do have thicker caps...but the block itself isnt' much different than a regular production pre-79 block from what I've seen. Oh, and not all of them have the knobs on the front near the water pump...the only way is to decipher the casting numbers and look in the valley where it reads "hecho en mexico". Boss blocks are very strong, but fall into the rare & expensive category, unless you luck out and find one cheap somewhere. When building a 302 of that nature, the weak link is the block...they start to show signs of flexing at around 450-500 HP level, and we all know how much cast iron doesn't like to flex without cracking and breaking. The stock crank is plenty strong unless you're spraying it or turbo/supercharging...and in that case, an aftermarket block is more of a necessity rather than a luxury. An 850 carb or larger would be a great idea as well as a Victor Jr or Parker Funnelweb intake manifold. The 302 that I ran for years was very simple, stock Performer RPM 2.02 heads, TRW heavy 11:1 pistons (true compression ratio was about 10.6), a Lunati 240-246@ .050" .518-.541 solid roller, and summit H beam rods. In my maverick it went as fast as 7.09 @ 98 in the 1/8...with open 1 5/8" Hedman hedders and a C4 w/3900 stall Fairbanks converter and 4.86 gears. I built a 351 and gave dad my 302, and he went with the SRP lightweight 13.8:1 pistons, and the reaction times and 60' times were about .1 better because the engine would rev so much quicker, but the actual ETs werent' that much different--most likely because of his semi-restrictive headers and smaller carb (I ran an 830 HP annular and he ran a 750 DP.) The bottom line, do your homework and don't be afraid to ask questions...there's lots of folks here that have real-world experience that are more than eager to help.
Thanks for all the replies guys! Pre-'74 blocks are a dime-a-dozen around here, so i might go that route if i can't find a mexican block. Good bolts are a must, and a girdle sounds like a good idea too. To be honest, i'm kinda doing this on a budget. The crank, rods, and pistons i got in a package deal on ebay for $335 (4340 crank, ford motorsport forged rods, and TRW forged 11:1's, all balanced). Also, this is going to be a daily driver , so i don't want to get too wild with the cam. I'm completely open to suggestions on a good cam, but i would like to stay under .600 (then i have to upgrade springs, and i think valvetrain gets a little less stable somewhere around that lift). I'm also going with a Victor Jr. intake, and using a proform main body (780 cfm). I work for a professional head porter, and i'm having him go wild on my heads and probably intake as well My last engine ate a lobe off the cam (this is the second time), so i'm just gonna pull it and start fresh.
I am pushing alot of ponies/torque for a stock block......and I know that its time is limited. But I agree with you that the $$$$$ sure makes the decisions alot easier. Get it internally balanced, girdle and ARP stuff and it should be fine.
