Everything posted by ifixedit
All I can say is don't waste your time with the 305, also there is ZERO chance it will make that kind of power throwing on the parts your buddy has, if it was possible to double the power with those 2 items everybody would be doing it. With those parts it might make lower 200's to mid 200's at best, but that's if you can even use the parts in the first place, read on. Yes, admittedly there's folks and some videos out there showing where guys have gotten decent power out of the 305 but it doesn't come that easy or that cheaply and the saying is "there's no replacement for displacement." First off, the 305 TBI heads have smaller combustion chambers than the Vortecs do, so swapping to Vortecs will do you no good as they come stock @ 64cc which will lower your compression. On the plus side, although compression is important, it isn't everything and flow is where it's at TO AN EXTENT depending on the engine and intended use, desired RPM levels, etc., etc. Too much flow with the wrong combination and again you kill power down low and the 305 needs all the help it can get, this is the reason they used the smaller combustion chambers, ports, and valves in the first place, to keep compression up a bit and increase velocity with smaller ports and valves which bumps up the lower RPM power. The benefit to the Vortec heads is their larger valves, superior flow and superior combustion chamber design. The problem though is attempting to put them on the smaller cylinder bore of the 305, you may actually have to notch the tops of the cylinders in order to give enough clearance for the valves to open, in any case the smaller bore of the 305 will shroud the valves and will kill power. Cam selection is next, I haven't looked up the LT1 cam you mention but I'm guessing it's nowhere near what you will want in terms of specs for a cam which is intended for a completely different application where it is likely designed to see 6000+ RPM max where the cam makes it power in the upper numbers, something you don't want for a street driven pickup truck, with that cam and the incorrect mix and match of parts designed for an entirely different application the thing will be a dog out of the hole and it will have no low end torque and acceleration. With a 5 speed manual you do have some benefit of being able to wind the thing up when you launch, but I'd doubt it would make much power until you hit 3500+ RPM, again very undesirable for a street driven vehicle, you will hate it. I'd be looking for a cam that makes lots of torque, you want to stay around a max of .450 lift (probably less), shorter advertised duration in the 200 - 220 degree range, and a lobe separation of 112 - 114 degrees. Which brings up the next problem which is depending on whom you talk to stock Vortecs are good for a max lift of around .450 lift, could be a bit more but this is an issue with stock Vortecs without some machining work. Unless your friend had the heads machined to accept a higher lift cam, the LT1 cam is probably beyond the lift the Vortecs will take. Still yet, we haven't even gotten into the tuning issues with the EFI, probably another nightmare. I believe Comp Cams offers a camshaft suitable for the TBI 305 and I'd investigate that first. If you're looking to bump up the power, Dart does make a very good small combustion chamber (I believe 58cc) cylinder head that provides very good bottom end, good velocity in the ports for low end power and may be suitable for a 305, otherwise I'd be looking at picking up a 350. The only other choice I'd really chase is have your current heads worked on to improve their performance, check out Comp Cams or similar grind and select the proper cam, you will be much happier with the end results. Here's a very good video to watch (see both part 1 and part 2) concerning Chevrolet heads including TBI / TPI's. >>
A little update for anyone reading this. Turned out the culprit in the end after I chased every other possibility was the damn wiring harness that goes from the accelerator pedal through the firewall to the TAC module. If you think this could be the issue or to see if it possibly is, start your truck, let it idle and wiggle the wires going from the accelerator pedal to the firewall, you may suddenly notice a change in idle speed or it will prompt the truck to go into reduced power mode. It can be tough to duplicate this repeatedly as I could not get it to do it every time, but of course would do it at the most inconvenient times like when I was on the freeway, then you gotta pull over, shut the truck off and hope it re-sets, all the while damn near getting ran into (not good). Another test is to turn the key to run (don't start the engine) and push the accelerator pedal all the way to the floor and release it, this in my case 8 out of 10 times would also cause it to display 'reduced power mode.' My solution was to go to a junkyard, I plucked a complete accelerator pedal and harness assembly from a clapped out '03 for $35. DO NOT UNPLUG OR TAKE THE ASSEMBLY APART AS THIS COULD CAUSE CONNECTIVITY ISSUES, JUST LEAVE IT ALONE! Take your old pedal assembly and harness out and replace it entirely as complete unit with the new one. GM must have made a mid- year change as I noticed the one I got had heavier gauge wires compared to the one I took out. My truck did have to 're-learn' the range of the new pedal (no big deal), but I've been driving the truck about 6 months now and no reduced power mode at all. Good luck!
I've read of a few gripes here and there on the modern ramp rates being a bit too aggressive and of failures due to this, but I would suspect most likely the problems are due to someone not doing things correctly in the first place. I decided to go flat tappet on my latest project as it was more or less a refresh than a rebuild and I couldn't justify the $700 (or more) just for the cam and retrofit roller lifters on this particular project. Gotta save it for a stall converter and better heads! Now back to our regularly scheduled program.... Rebuild a sbc 400 or?
True, you can go with retrofit roller lifters to avoid the flat tappet break in issue, but there's still plenty of oils out there like Valvoline VR1 providing the needed phosphorus to break in and use a flat tappet cam. Just broke in a flat tappet myself BUT maybe a roller next time around. ;-)
When you get to the camshaft part, this one comes highly recommended. >>> http://www.summitracing.com/parts/hrs-112571-12?seid=srese1&gclid=CjwKEAiAvauyBRDwuYf3qNyXmW4SJACX9-fXEAr1Jyt-2ux79zCCMzrXySTYZQzb0ME-ktHvgR5jthoCMkTw_wcB
None should be wet but that all depends. When the head was made / machined and someone (or something like a mis-adjusted machine?) could have gotten carried away and got down into one of the water passages. If you suspect this a little thread sealant on the bolts isn't a bad idea.
Yeah, sorry to hear this, what a mess. I'd be trying the same, get under the front edge of the key with a punch or better yet some kind of punch with a narrow flat end that fits in the key-way, that key can't be stuck in there that firmly. Unfortunately, it does look though like the end of the crank is pretty boogered up and the key-way itself is ruined. Looks like at some point by the evidence of the JB Weld that the balancer completely spun all the way around on the end of the crank, taking out the key-way in the process and it really messed up the entire end of the crank. Perhaps time for at least a different short block? That or you do a budget repair, find a good used crank, yank the engine, replace the crank, rod and main bearings, timing set, etc.? Either way it's gonna be a hassle at this point.
Is it possible the vibration you're feeling actually a miss?
1994Vmax offers some good advice. A junkyard LS will make 400 hp pretty easily and run very smooth, the bigger the LS, the easier the 400 comes. If you stick with your original small block 400 the key is getting the right cam, and better flow and the compression bumped up (mostly from the right heads), from there it all depends on where you want your power to start. The cam profile recommended would work well, keep your LSA in the 112 degree range, it will idle smoothly and you will make nice bottom to mid range torque which is what you want for a heavy vehicle. The HO 350 cam profile and similar grinds are good torque makers and places like Summit are good places to shop for stuff reasonably priced. If you want a lopey idle then a higher stall converter will be in order for an automatic trans and your power starts to move upstairs. Either the iron Vortec or Dart heads mentioned are very good power makers, both are much better than any other stock chevy iron head even from the 60's, but with the vortec heads it requires center bolt valve covers, special vortec bolt pattern intake, self aligning rocker arms and your lift is limited depending on who you talk to at around .480 + or -. They also have pressed in rocker arm studs. For not much more $$ I'd go the iron Eagle head route, you should be able to get an assembled set for around $900. With 64cc chambers and a stock bottom end with the pistons down in the holes a bit and dished pistons you should end up around 9.0 to 9.5:1 compression, do some bottom end work and get flat top pistons up at deck height and things get better. Hot Rod did a junkyard 350 a number of years ago where they yanked a 350 out of a 77 Impala (hardly performance oriented) didn't nothing to the engine other than bolt on parts, and got just over 400 HP using vortec heads, carb, intake, cam, headers, etc., none of it was anything special, so 400 HP is very realistic. If you feel the bottom end of your 400 is in good shape, bolt on the parts mentioned and have fun!
Now that I have a chance to look over your latest picture again this morning on a larger screen, it appears to me anyways that on the later SBC's that they incorporate 2 separate keys, one for the lower timing chain gear and one for the balancer, my old 350 only uses one key for both. In any case neither key are really sticking out high enough to secure the gear or the balancer, and both could be easily sheared which seems to be the case anyways for the balancer, it looks like the key was sheared off at some time in the past and the balancer spun on the end of the crankshaft. Both keys certainly look like they've allowed movement of both the gear and balancer. Also note the gap between the key and the inside of the key-way in lower gear, that gear is ready to shear off the key as well and I can see damage to the gear key way, everything has been moving around and it's all a pretty sloppily assembled situation. Again, if you can get both keys out and clean up the key-ways (and that isn't JB Weld forming part of the key-way) and get the correct size keys fit in, with a new timing set and an undamaged or new balancer as well, you may be able to save it. Keep us posted.
Oh great, JB Weld! Someone did the old quickie fix job and sent it down the road. From the picture the key way doesn't look all that bad. Get the lower gear off, get what appears to be the remaining portion of the old key stock out of the slot and see what you have. If the slot is mostly straight and not too damaged you may be able to clean it up with a small file, get a new key, make sure it fits snug in the slot and then closely inspect the slot in the balancer as well. Since it's a lot tougher to change a crankshaft, at least make sure the slot in the balancer is perfectly straight and undamaged. If it's at all questionable find a new balancer. It looks like whoever did the previous lousy repair job was either in a hurry or was being lazy and was too cheap to go get a new key. You may be able to save it!
Yeah, I hate to say it, but it doesn't look too good. Looking over the pics again I can see the circular wear pattern out towards the end of the crank snout indicating the balancer has been rotating back and forth on the end of the crank which would take out the key-way. From the marks and pitting it looks like it's been doing that for quite some time and something finally moved enough to cause it to make the noise you heard. Was probably the balancer banging back and forth on the loose key-way. You might get lucky enough to clean up the key way, secure a new key in it, and find a good balancer (as I'm sure the one that came off is junk) and put it back together. If any part of it is questionable though, how long it will last that way is a crap shoot at best. The balancer has got to be on tight and secure as they are what absorbs the rotational forces and pulses of each firing, something a loose or questionably secured balancer will not handle for long.
Well, it doesn't appear that it has jumped a tooth, but the chain is very stretched, especially if you can get that kind of slack on both sides of the chain. I'm also looking closely at the key-way and the key-stock on the crank snout, it's hard to tell from the pictures, but both look a bit beat up and out of alignment, I also see what appears to be metal shavings on the key-stock. The key-way in the crank snout where the key fits should be nice and straight and clean with everything lined up, it doesn't appear that way from what I can see, it looks like something there shifted, like the key-stock itself is broke in half closest to the lower gear. Hopefully the end of the crank and key way is not damaged, if it is the thing is a goner or very troublesome to fix at best. Does your harmonic balancer show any damage? Looks to me like there's some kind of damage there and the balancer itself was damaged and or moved out of position and is what was causing the noise?
You may just be having more of a where you are buying your fuel from problem. I've noticed rather varying grades of gasoline depending on where I buy. Most 87 - 88 octane (or some advertised as premium for cheap) especially from the cheapo discount stations is about as good these days as watered down cat pee, run it in your lawnmower but not your truck. On most of this crap my truck pings like crazy, from a few other stations the 87 octane causes no problems at all or very slight pinging at times, but it also depends on the season and the blend being sold at the time. I'd suggest taking a trip to another gas station first. Drop a tank of premium (91 to 93 octane) in it from a busy, national brand station and see if your problem goes away. It's tempting with the cheap gas prices right now, but I generally use ONLY mid grade and up and never a problem.
With any luck at worst you've got a few bent push-rods and nothing more. It wouldn't have even been running any longer if you had pistons slamming into valves and so on, that would take a severely jumped (by several teeth) timing chain so I wouldn't worry too much there, the chain is probably badly stretched and is off by one tooth and you might be missing a tooth on the upper gear. Regardless, now that you're in there you'll want to install a new timing chain and gear set, then take every push-rod out and inspect them for straightness, if you need a few new ones you could always rob what you need from an engine at a junk yard. If you opt for used push-rods just be sure they are the exact same length and that the center of the push-rod is clear from one end to the other so the oil can flow through them. If they sit for a long time the hole in the middle of the push-rod can plug up from the dried up gunk, they're easy to clean up and make like new though.
And definitely don't use a foam brush, that's about the worst possible choice you could come up with. If you don't have one already, pay a visit to the local hardware / home improvement store and buy a brush that's specifically for applying varnish, it will generally say so right on the packaging. I'd also buy an angled brush vs. a straight one. I've found foam brushes to be just about worthless for anything, some use them for staining but there too I'd prefer a good old cotton cloth over a foam brush as well. I think they work O.K. for scrubbing toilets! ;-)
I do a little wood working on the side. Basically a "polyurethane for floors" is just a better quality varnish meant for tougher use, like a floor. Part of whether you want to use it or not will depend on its finish (gloss, semi gloss, satin, etc.) and what you prefer for a finish. Other than that I see no reason you couldn't use it on a door. The main thing with using any type of varnish is starting with a good clean, well sanded and dust free surface (and working environment). Don't shake the can, this produces bubbles, thoroughly stir it first and you can then brush it on straight out of the can if you like. Brush it on in decent but not sopping wet coats (use a good brush meant for varnish, plan to spend $8+ on the brush! Be patient and wait for each coat to completely dry (usually takes over night), and then apply the next coat. The first coat even after several hours may still seem a bit tacky, this is normal, after the second coat that will go away and will completely dry. You'll want to do at least 3 coats. You can lightly sand between coats with 220 grit sandpaper or steel wool, use a tack cloth to remove the dust, and apply the next coat. When you're finished with a coat, have an old coffee can or equivalent on hand with some paint thinner or mineral spirits in it to clean your brush so it's ready for the next coat, I just leave the brush immersed in the thinner so it doesn't dry out. Use an old towel, etc., first to dry the brush after it's been soaking in the thinner before you put on the next coat, and you should be good to go.
I sell commercial truck tires for a living and do a few pick up tires from time to time as well. As a rule of thumb and to be on the safe side I'd just go ahead and put 10 ply tires on it and not take the chance with the P metric tires, they're made to carry the vehicle and not much more. Anything above half ton and you for sure want 10 ply, anything below 3/4 ton and it all depends on if you are ever towing or hauling heavy loads, I'd still just go 10 ply and play it safe. Load ratings (actual weight capacities per tire) varies by tire size. You should be able to look up your tire on the internet by going directly to the MFG's website, look up the model and the size in question and they will give all the specs and ratings. Longevity of a tire depends on vehicle maintenance, tire rotation, shocks, alignment, wheel balance, driving habits and so on. Assuming all this is good, running the proper air pressure is then the most critical.
I ask about the backfire because it is probably what caused the timing chain to jump a tooth. Now that I think about it, unless you really know what to do, finding top dead center won't do much for you as you have to know how to determine proper cam lobe lift timing in relation to rotation after top dead center. I'd instead get the timing chain cover off ASAP and get a look at things in there, it will probably be pretty obvious once you get in there. You'll probably find at a minimum a badly stretched chain, perhaps a tooth missing from a gear and so on. If things aren't real obvious, you can then roll the engine over and see if the timing marks on the gears line up or not like I provided in the illustration above. As far as the rocker arm adjustment goes, that's pretty simple. Once everything is back together, simply rotate the engine going one cylinder at a time and just as the lifter for each cylinder's intake and exhaust are beginning to come up on the cam lobe, tighten the rocker arm nut down to zero lash (tightened just enough to get no play between the tip of the rocker arm and the valve stem), this will be your initial setting. Then once you've gone through each cylinder, exhaust and intake rockers adjusting each to zero lash, you can then go ahead and start the engine and do your final adjustment of each rocker. You will want to stop by the auto parts store for some oil deflector clips to attach to the rocker arms so you don't have oil squirting and running all over the place while you make the final adjustment on the rockers. As you adjust each rocker arm nut with the engine running, typically most will call for slowly backing off (loosening) the nuts on the rocker arms one at a time until you hear clicking, then slowly tighten the nuts a quarter turn at a time, pause a second or two, and continue a quarter turn at a time until you've made a half turn total, and you're done. Some will call for the same procedure, quarter turns at a time, and end up at 3/4 of a turn total, I've always gone with a half turn total. In any case, I'm now betting your timing chain jumped.
Definitely another possibility. If you're 100% sure it's not the radiator AND the water pump has considerable miles on it, then it's got to be the pump, the gaskets as txab mentions could also be deteriorated. Might as well just jump in and get under the hood and get at that pump.
The way you describe things "just dumps right out onto the ground" makes it sound like the lower radiator hose is possibly split or there's one big honkin hole in the radiator somewhere. Does the radiator even hold coolant? If you look inside the radiator with a flashlight, can you see coolant? When you add coolant does it leak when the engine is running or when it's off, or both? It could also be one of the side tanks on either side of the radiator is leaking. The radiators on those years in my opinion are kind of wimpy and over time it doesn't take much other than normal wear and tear, vibration, etc., to make them leak. Like my 98 Yukon, yours should also have the radiator with the plastic side tanks, so you could be due for a new radiator. If you need a new one they aren't overly expensive, I picked up a new one a couple of years ago for my Yukon for $150 at Carquest. When it does leak, crawling under the front of the truck with a flashlight should certainly show where the leak is at.
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