First 302 rebuild....any tips? January 26, 2009, 08:48:46 AM I've started reassembling my first 302 rebuild this weekend. It's nothing special. Just a stock rebuild with a new crank and reused pistons. The block has been cleaned and honed.I checked the crank with plastiguage and everything is spot on middle of the tolerances. I am using a royal purple assembly lube (the oil system will also be primed prior to startup).Anything I should watch out for?Thanks,DZ Quote Selected
First 302 rebuild....any tips? Reply #1 – January 26, 2009, 12:24:20 PM what was the plasti guage reading? Quote Selected
First 302 rebuild....any tips? Reply #2 – January 26, 2009, 12:59:55 PM What are you looking to accomplish EX. (HP, STOCK, MILD, WILD) what pistons are you going w/do they have valve reliefs and EFI or CARB..oh and whats your buget Quote Selected
First 302 rebuild....any tips? Reply #3 – January 26, 2009, 02:18:42 PM Check piston ring end gaps and space the gaps. Keep everthing clean. Quote Selected
First 302 rebuild....any tips? Reply #4 – January 26, 2009, 04:14:47 PM Make sure the bottom headgasket bolts have RTV on them. They go through the water jacket. Quote Selected
First 302 rebuild....any tips? Reply #5 – January 26, 2009, 04:58:46 PM Plastigauge was, by my estimates, around .0015-20, my book says anywhere between 10 and 30 is good to go. Haven't installed the rods yet, that's tonight.Stock HO pistons. Its an HO block. I already have all the parts (new double roller, E7 Heads (unless I find something better cheap before I install them), new WP, new freeze plugs, Stock HO cam with roller lifters numbered before removal. I made my typical "Box-o-Holes" and everything is numbered rockers, lifters, pushrods..etc. As for cleanliness, everything is clean and stored in sealed tubs. I need to finish cleaning the piston surfaces. I have done a few headgaskets (3.8SC, 5.0, Saab 2.0), just never a bottom end. This is basically a re-ring. Its a learning experience, the car isn't really worth dumping a high buck motor into. I just always wanted to assemble an engine. Its pretty low-buck. Quote Selected
First 302 rebuild....any tips? Reply #6 – January 26, 2009, 06:07:26 PM As stated before, keep everything clean.Check, double check as you go along. If you torque a connector rod. spin the crank to make sure it didn't lock up. Oh, a good torque wrench is essential!Take your time. Don't get in a hurry. That is where most people make their mistakes. Quote Selected
First 302 rebuild....any tips? Reply #7 – January 26, 2009, 08:12:56 PM Quote from: Kitz Kat;253709Check piston ring end gaps and space the gaps. Keep everthing clean.actually,, this is where its all about and where you will make the most measureable gains on your work that you can feel. measure top /middle / bottom of each cylinder with a compression ring sliding it down with a piston you have lying around.Its almost worth it to open up your stock set and make the end gap measurements something you do now. It would be highly worth the time to exchange your stock kit for a 10 over set then file the rings down by hand so you end up with .001 +.Gapliess rings overlap eachother on the ends. Quote Selected
First 302 rebuild....any tips? Reply #8 – January 26, 2009, 08:28:59 PM Shouldn't there always be some gap on the rings. If your at 0 gap, when the engine heats, won't it press outward and wear fast?What will reducing the gap get me? Quote Selected
First 302 rebuild....any tips? Reply #9 – January 27, 2009, 01:16:49 AM part one answer=Yes but how much I have no linear way of calculating it nor does anyone else. The answer being yes is common sense but how much is the queston. To suplement my previous post, i included "gapless rings which overlap. My febal attempt to show this is in the drawing.part two answer=substantial increased compression, less contamination of unburnt fuel in the oil, increased horsepower just to name a few. what happens in the cylinder is half of what an engine is all about. Keep in mind that compression increase makes you want to put 10 or 20 more dollars on a better head gasket (just my opinion). A copper set would be really cool and is reuseable. The other half is air and fuel. increase one or the other or both and you create or improve on factory acceptable specs. I remember not too long ago asking ford what an acceptable end gap is,,,,,,,check the specs also and you'll see what i mean. If you can control the valves sealing and the rings compression loss, the rest is air and fuel which are both controlable and managable without spending money. None of this costs any substantial additional money if you have your own tools which evidently you do.If you lap grind your valves like i mentioned and then also added a thin consistant shim to all valves, you are also creating more of a seal inside the cylinder when the explosion happens. Quote Selected
First 302 rebuild....any tips? Reply #10 – January 27, 2009, 01:36:25 AM Quote from: jcassity;253813 included "gapless rings which overlap. My febal attempt to show this is in the drawing.don't use gapless unless you new bore the cylinder block.gapless DO NOT LIKE TAPER CYLINDERS. because as they go up and down in a uncircular tapered cylinder. they build up friction that dissociate the over lap part of ring.whick put the junk in the oil, then takes out the bearing. i had it happen to a close friend of mind when he did it to his.taper cylinder=that what your cylinder are when the top of your bore is bigger than the bottom.rering jobs only use just the factory style ring best.. Quote Selected
First 302 rebuild....any tips? Reply #11 – January 27, 2009, 01:39:11 AM Quote from: danzajax;253729Plastigauge was, by my estimates, around .0015-20, my book says anywhere between 10 and 30 is good to go. Haven't installed the rods yet, that's tonight.Stock HO pistons. Its an HO block. I already have all the parts (new double roller, E7 Heads (unless I find something better cheap before I install them), new WP, new freeze plugs, Stock HO cam with roller lifters numbered before removal. I made my typical "Box-o-Holes" and everything is numbered rockers, lifters, pushrods..etc. As for cleanliness, everything is clean and stored in sealed tubs. I need to finish cleaning the piston surfaces. I have done a few headgaskets (3.8SC, 5.0, Saab 2.0), just never a bottom end. This is basically a re-ring. Its a learning experience, the car isn't really worth dumping a high buck motor into. I just always wanted to assemble an engine. Its pretty low-buck.Ignore what I said first I jump the gun a little on what you were looking for that’s what I get for watching TV and reading at the same time. Anyway you stated you might be looking for cheap heads in place of your E7s I used iron GT40s off a 97 explorer stay away from the GTP heads. And the intakes to are gt40 too. Just my 2 cents Quote Selected
First 302 rebuild....any tips? Reply #12 – January 27, 2009, 10:22:47 AM I read up on the gapless and ordered standard (+10) rings (the standards I had were .0002 over the max ring gap. I will grind the +10s to perfect tolerance per cylinder. I read about quite a few problems with gapless rings as well as most statements that they only buy about 5 hp and cause problems. I always use Felpro gaskets (had really good success).I wish I had a set of GT40s but they go for about $350 + $75 dollars shipping on ebay. Anyone know where I can get a decent price on a pair? I was thinking about going to the boneyard and pulling a Pre-74 351w heads. Quote Selected
First 302 rebuild....any tips? Reply #13 – January 27, 2009, 03:17:43 PM QuoteI wish I had a set of GT40s but they go for about $350 + $75 dollars shipping on ebay. Anyone know where I can get a decent price on a pair?Forget EBay go to your local junkyard and tell them your looking for heads for a 96’explorer. You might not want to tell them what your doing the price might go up. I paid 100 a head and 150 for the whole intake set-up off a 97 explorer. 97¼ and up were GTP. Quote Selected
First 302 rebuild....any tips? Reply #14 – January 27, 2009, 04:56:13 PM Quote from: Innes;253816Ignore what I said first I jump the gun a little on what you were looking for that’s what I get for watching TV and reading at the same time. Anyway you stated you might be looking for cheap heads in place of your E7s I used iron GT40s off a 97 explorer stay away from the GTP heads. And the intakes to are gt40 too. Just my 2 centsWhat's wrong with the gt40p heads? worked fine for me and bunch of other people i know... Quote Selected
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