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My third Gen has sadly been sitting in the garage collecting dust. Down to one final Gen 1 SBC, along with a garage full of Gen 1 parts in which I'm lucky to remember what I even have left. Lots of parts left over from previous builds, so I'm looking to slap together what it is that I do have, to not only have some fun with the ole girl this summer, but to get her to at least move on her own power. Lots of items I still need to order, small stuff, but will take longer than normal because of what's going on in today's world. Anyway on to the project...;
Pulled the heads off of yet another non-roller 305 SBC with one piece rear main seal, and to my sad sad surprise, I was presented with dished pistons. Not only were they dished, but they measure a whopping 0.080" down in the hole. Yeah, umm, ugh. Was bored 0.030 at one point though, with more cubes always being a good thing. But will have to make due with a very inefficient block as a starting point. Thought it over quite a few times, and yes, a 350, or any flat topped 305 would be a better starting point, but I'm not buying nor hunting the junkyards anymore, not even craigslist, those days are over. It is what it is, sadly. Moving on...
This engine is coded for an '86 truck, but its getting a Tuned Port Injection system that I have had sitting here for years, regardless. I just about siamese all of my TPI stuff, so it should be fine for this little project of mine. But, the heads were bone stock for that era, good ole 416 heads. Unsure if these were the original heads for this motor, as again the engine was already bored out, so someone has been in there already. But they are 416 heads nonetheless. So that is where I started, cleaning them, porting them, then painting them. Opened them up as much as they will possibly go, with no worries abnout hitting any water jackets. The stock valve springs are absolute garbage on these engines as I am sure many of you already know, and the exhaust rotators, well, lets just say rest in peace to them. Using stock GM parts from the 80's was always a pain in the rear though when setting up installed spring height, which is something I am still finalizing as I wait for my valve seals to show up in the mail...
This is essentially where I am at this point with this build. Heads are just about wrapped up, and next I will be selecting a camshaft. Now I am far from a cam "guru", as I was going to target a flat tappet cam from Lunati with much less duration than one of my previous builds, and I mean much less, I want to see 18" of vacuum at idle this go around, no more rumpity rump for me, I'm over that lol. Definitely open to suggestions before pulling the trigger, even looked at Summit cams for comparison. But getting back to the heads, rotators are gone, only shimmed the exhaust seat with two 0.060" shims, won't do three, not running any oil splash guards on the exhaust spring (which would help offset the rotator if I did) as I want the oil to hit the valve, however I'll more than likely run the oil splash guards on the intake springs. Had a set of aftermarket valve springs on the shelf, and since this is my final SBC build, I grabbed them and didn't turn back. So... now I have to compensate for the lack of rotator, but I won't do a third shim under the spring, so I'm looking at possibly buying offset valve locks (expensive for a freaking set of keepers), or exhaust valves with the proper groove location that matches the intake valve. I do have a set of 1.50" exhaust valves that match the grooves, was going to use them on a set of aluminum heads that I will be selling shortly, but I'm considering just taking them and using them. Still up in the air though...
So this is where I am. The short block is on the rotisserie waiting for new piston rings and bearings. This engine will not see high RPM, nor will it see mega boost. Just building a street car that I can drive back and forth from New Jersey to New York with no hiccups, but will have decent power for whenever needed. Will update this thread once I get my valve seals, and springs setup and installed properly... will then finalize camshaft, TPI system w/injectors and regulator, etc. No rush, doing this in sections as time allows...
416 cylinder heads opened to the max, welded EGR port where it is open on the TPI lower intake (just the one side). Roller tipped rockers w1.52" ratio, with aftermarket springs. The bowls have been opened up substantially. Would like to get these flowed beforehand, but what's the point. It's getting boosted. Just waiting on the seals, then I will lap and install the valves...
- Rob
Last edited by Street Lethal; 10-10-2022 at 10:18 AM.
Blue intake valve seals showed up today, still waiting on the exhaust umbrella seals. I mentioned earlier that I was still finalizing installed spring height, and it worked out very well. Exhaust side is using one shim under the spring, one shim under the retainer, and is using an intake retainer and offset keeper. The intake side is using a chrome moly retainer with oil shield and standard keeper, and no shims. I went with an RV spring on the exhaust side (90# give or take), and stronger spring on the intake size (120# give or take). Both with about a 1.72" installed spring height. This should allow me to run upwards of .515" lift on the intake side, but I won't be needing that much. Highest I am looking at with the next cam I am running with is about .474" with a 1.52" rocker....
Decided on the Lunati Voodoo this go around; 213/219 .454/.468 w/112 LSA...
Yeah... did that on a set of 128 aluminum's as well, works good. Never felt comfortable stacking shims on top of one another under the spring when getting rid of the rotators, and I would only do this with the stock style intake retainer on the exhaust side, not the chrome moly ones on the intake side. To update this thread I just wrapped up both heads as the black umbrella seals got here today. Also pulled out a brand new double roller timing chain that I forgot about laying under a bunch of old wiring harnesses. Once the cam gets here that should be it as far as valvetrain. Springs are much stronger than stock, but not enough to call for hardened pushrods, so the stockers should live.
All you are doin is adding mass to the spring/retainer and forcing it to do more work. You should keep it under the springs where it aint doing anything
is that a hyd roller? Seems very light on spring pressure for that. Probably will get float in boost
x2, what was the reason to put a shim between the spring and retainer?
Dig... the intake retainer holds it in place, and the shim itself takes the place of the oil shield anyway that I did away with at about 0.015". This needed to be done for installed valve spring height in order to run up to .474" lift ion the exhaust side, which I am running. Only difference with mine is I won't stack the two shims together under the spring. This really is nothing new.
Justin will you stop with the "good luck" crap lol, I hear you dude, and I appreciate your words. Trying to paint you a pictuire so you understand, the shim is taking the place of the oil shield on the exhaust side. It's basically the oil shield with no side skirts, the stock intake retainer locks it into place the same way it does the oil shield. I didn't want the shields though because I want the exhaust valves oil cooled...
Tom, I really didn't start this thread to create a debate with members, I'm sharing my last third gen build with this website. Stronger springs, boost pressure, both reasons to consider hardened pushrods to help with stability. Low lift and low RPM may allow for the stock 305 pushrods to live. If they bend, I'll replace them with hardened. I also just pinned the stock pressed in studs this weekend, so it's not the matter of why I would do that, or reasons pins for example are needed, it's essentially what I want for this build...
Had a few members PM me asking if I were still alive lol... yes, sorry for the lack of updates. Have quite a few of them, but wanted to wait until the bulk of them were finished. Focused my attention on the front of the car in the interim, as my last build had me hacking up parts to accommodate a turbo system, parts that are getting harder and harder to find, whereas now I am installing everything back the proper way, and fitting the turbo system to the way the car sits. Took awhile but Classic Industries finally sent me my new front crash bar... but they didn't have the crush material, so had to buy that from an online auction. Stuff is getting harder and harder to find. Then there is the matter of the factory fog lights. Pulled them apart to install some nice LED's, but that has also become a project, as I need to sand, paint and re-tape (mirror tape) the insides. Luckily the wiring is fine. Keep forgetting the car is thirty two years old now, Christ time flies. Should have the front wrapped up soon, but then I need to order a much smaller FMIC. I still have a 4" FMIC with 3" inlet/outlet, but it's way too tall to fit in front of the radiator, and I am not cutting anything. I found a nice one on ebay that matches it though, with the only difference being it is half the height. Already ran the intake tubing based on its' measurements alone, and it works out perfectly. Will it work in terms of IAT reduction though... well It's going to have to. Again, just a simple street build fella's, not a track car. Also will be running E85 anyway, so I'm not really that worried about IAT's. The White on the crash bar was a sticker from Classic Industries, got the rest off after taking the pic.
Well this summer came and went, as they always do. Made a few changes to this little project, buddy talked me into pulling the claimer inspired 310 and putting it to the side, and he offered me his '86 305 out of a Caprice w/40,000 original miles to have some fun with. Engine was just sitting, so I grabbed it. Original 305, nobody's hands were in it yet, just needed some love. Got it down to the short block then loaded it up, Better quench, and stronger factory flat tops. Also have the original balancer and flywheel. Removed the rods and pistons, still setting ring gap, looking at around 0.026 and 0.028 tailored to the individual cylinder. The stock rings were still sharp, but I'm not reusing them. New main bearings alrerady installed, old bearings looked fantastic. New rod bearings when pistons go back in. Other than that not really much to update. I did nab a new Jegs cam, Crane lifters and Comp pushrods, and the specs on the cam are very different from what I was originally looking for, but it is what it is, too good of a deal to pass up...
This is just before we disassembled it...
Loaded it up...
Quick inspection of it before pulling the pistons out with some light cleaning...
Rods & pistons removed, short block power washed, then painted. New cam & stock crank w/new main bearings installed.
Haed gaskets are still up in the air, no rush with this whatsoever. Going to wrap up the ring gaps, clean the cylinders because they've been sitting, then reinstall the pistons. Just waiting on aluminum waterpump, high pressure oil pump, and head gaskets...
- Rob
Last edited by Street Lethal; 09-16-2022 at 10:28 AM.
Slow progress is still progress... insatalled one head on the engine yesterday, other one is going on today. Compressed thickness of the head gaskets being used is right at 0.026", with static compression coming in at around 10.25 or so. Cam isn't too forgiving either, but it doesn't matter as I decided on E85 when I first started this project either way...
Compressed thickness of the head gaskets being used is right at 0.026", with static compression coming in at around 10.25 or so. - Rob
Rob, would you mind telling em more about the 305 head gaskets you chose? I haven't found any that have a compressed thickness as thin as what you are describing.
Rob, would you mind telling em more about the 305 head gaskets you chose? I haven't found any that have a compressed thickness as thin as what you are describing.
Of course, the GM head gaskets are advertised as 0.028 compressed, but can be anywhere betwen 0.026 to 0.028 compressed, from our experience anyway, with a max bore size of up to 4.00. I would honestly recommend custom Cometics for others wanting to boost a 305, I ran Cometics last time out and they are very strong, but I have had success with these GM gaskets in the past and they were lying around the garage, and this engine definitely won't be seeing any higher than 12-psi of boost, so they should hold very well. I don't want to get too carried away with this engine stand, as although its rated for the correct weight, I'm not going to subject it to a full engine dress up. I stripped down the oil pan and started painting it yesterday, I scrapped the stock oil pump and installed a Summit high pressure pump, and also replaced the one piece rear main seal. Once the pan goes back on, I'm going to install the engine then wrap it up...
- Rob
Last edited by Street Lethal; 10-10-2022 at 06:58 AM.
Lol, you originally said "no rupy rump camshaft," that you're over that. 224/234 is going to make a 305 do the cha cha, no matter what the rest is.
Last build... last SBC build, last 3rd gen build, last car build...? Are you planning on disappearing from here when you're done? You're making it sound depressing. What car is it going in?
I'm slowly putting together something similar but with a completely different attitude. It's getting all the good stuff that I've collected and saved since the 90's (I bought my original 83 Crossfire car in 91), sort of the car I should have always built. You're having problems finding some pieces, where I have things like a factory aluminum bumper support, "factory" (they weren't made by the factory but they were sold as a factory option) 'glass '88 Pontiac notchback, I've always wanted to dress a street 3rd gen like a road race freak so it might get a custom wing of sorts to match that style (think kind of like a C5 ZO6 Notch race car), weight jacks/rear coil overs, I'm planning paint already and I think I have all the factory seals in boxes, widened factory wheels, the best cylinder heads I could figure out how to make work on a 305 without getting a second mortgage. Everything is lighter, stronger or something I've always wanted to do but didn't do for one reason or another.
Mark, I'm sure your build will come out sweet. However the Jegs cam is a drastic change from my old Lunati cam, and its not so much the chopping that I want to do away with, but the lack of vacuum at idle. This cam will give me closer to 16" of vacuum at idle, which is exactly what I am looking for. But we'll get into that when I turn the engine over for the first time. Nothing really special with this build, not pulling out all stops, just want a strong and reliable runner, with emphasis on reliable as it needs to get me back and forth to New York with no hiccups. This will in no way dominate the street racing scene in New York, but it has to at least hold its own. But anyways, as far as my last SBC build, sadly yes, but this isn't like saying cue the Incredible Hulk ending theme, and I'll wave while walking away (lmao), I'm still here giving back and tuning engines for members...
But anyways, Caprice oil pan didn't work out, it looked similar, but doesn't clear, and I am not massaging it when I have another one that I know will fit with the turbo header crossover with no problems. Just need to strip and paint that one now. I converted the stock regulator to an adjustable unit, and painted it to match the engine. Fuel lines cleaned and painted. Rails were polished, but got dirty from my gloves, so need to re-polish them up after installation. Valve covers also painted the same, and the passenger cover fitted with inlet to relieve any possible blow-by in the crankcase, with a hose running from the mechanical fuel pump to the valve cover. Other oil pan already has turbo drain welded in it. Tuned Port Injection again siamesed and ported as much as it will go. Air flow will not be a problem up top...
- Rob
Last edited by Street Lethal; 10-22-2022 at 10:19 AM.
This cam will give me closer to 16" of vacuum at idle, which is exactly what I am looking for. But we'll get into that when I turn the engine over for the first time.
I'm curious about where you're going with that.
FWIW, this is a roughly (long story) 218/218/114 in an <8.6:1 305. You can definitely tell it's there but vacuum hovers in the >17 range depending on the ignition tune (the heads flow enough that even with the smallish cam it wants to rev WAY past 7000rpm:
idle on a cold night:
Nothing really special with this build, not pulling out all stops, just want a strong and reliable runner, with emphasis on reliable as it needs to get me back and forth to New York with no hiccups. This will in no way dominate the street racing scene in New York, but it has to at least hold its own.
The street scene is interesting here, I'm guessing similar to up there. There are a lot of Hellcats and Corvettes with thousands in their builds, making way more HP than something like this ever will, BUT very few know how to drive, and even fewer know how to do it on the street. A solid 12s car with a good and smart driver can make a few $100 easy.
04-26-2022 | 06:53 PM
