The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by Fat Hack, Jul 5, 2012.
Ok here's a dumb question. Can you bolt on 350 heads to a 305?
As long as the valves are under .202 you will be fine.
350 heads work on a 305 as stated, so long as you go with the 1.94" valves or smaller. The 'problem' is that most 350 heads have larger combustion chambers than the 305 heads do, so your compression ratio will drop unless you change pistons. If you're rebuilding an engine, then replacing the stock dished pistons with flat-tops will gain you back some of the compression lost to combustion chamber size.
Patriot offers aluminum heads with 1.94" valves, but they aren't readilly advertised through Summit or Jegs. Your best bet is to contact Patriot Performance directly about them.
I will cover more aspects of this particular build as it progresses. It's something of a 'sideline project' since I have no intended use for the completed engine, and machine shop downtime is always a factor.
There are three distinct directions that I'm mulling over as far as where to take this engine, but whichever way I end up going with it, I will try to cover alternative parts and procedures related to the two paths not taken. For the record, the three Plans are:
1. Basically stock rebuild. This would include a complete and thorough rebuild using all new, quality parts. Machine work would include little more than a bore and hone. Pistons would be stock replacement cast units with standard iron rings. Heads would be SR Torquer 305 heads from World Products. I have a like-new cast iron 77 Corvette intake manifold and Quadrajet that would be used, along with refurbished F and G-body exhaust manifolds. Distributor would be a standard HEI and the final assembly would include a long water pump and appropriate accessories and brackets as well as a stock replacement mechanical fuel pump. Camshaft would be a stock replacement 1274 cam for a 350 engine. Just a smooth, economical and reliable daily driver mill.
2. Hot Rod Version. This one would up the ante a bit with flat-top pistons, aluminum heads, a Crower 'Beast' cam (their smallest in that line, but still a healthy dual-pattern hydraulic cam), and an Edelbrock tri-power manifold topped with three of the new Edelbrock 94 carburetors. (That sounds excessive, but it's only 510cfm wide open). The distributor would be a standard points type and final assembly would include a short water pump, Carter mechanical fuel pump and Rams Horn style exhaust manifolds. A serious econo-performer that would make a great motor for your typical hot rod or early classic cruiser.
3. All Hell Breaks Loose. Ha Ha...I've wanted to do this one for a while with all the stops pulled out, just for fun to see how it would turn out. This would be a high dollar effort and would involve some of my crazy ideas such as de-stroking, notching the cylinders for 2.02" valves, steel crank, forged pistons, ceramic rings, belt drive, solid roller camshaft, aluminum heads, and a serious carb on a race type manifold with an aftermarket high-rpm distributor. Electric water pump and electric fuel pump to further reduce parasitic drag (and to, believe it or not, also maximize fuel economy in this wildest version!). Like I say...nothing cheap about that one, but it's something I've wanted to do for a long time!
Maybe I should put it to a vote?! This is just something I thought I'd do for the benefit of sharing the build with the collective enthusiasm of the HAMB. Like I say, I have no plans to run it in any of my intended projects, so I could go any route at all with it. It will be dropped off at the machine shop for initial inspection either tomorrow or Monday, and then it's on! I've got other project ideas in the works, but I'll continue to post updates and info as the motor comes together over the next few months or so.
Wow you're a fountain of 305 information.
Not to hihjack, but I have a mostly complete 1985 305 sitting in my shop that I pulled out of my '85 C-10 pickup a year or two ago. (No carb, no pulleys, not exhaust manifolds, but otherwise all there.)
It was running but smoking and sounding pretty bad when pulled. Anyone who wants it can have it if they come get it. It's even sitting on a homemade stand that is ideal for hauling in a pickup bed.
I am just a few minutes south of the HAMB Drags host hotel in Joplin, MO. PM me if you want it. (But be prepared to be flamed if you say you want it and then never come get it!)
I agree with you on detailing out the block before machining. I have my machinist check the block before I put any time into it. If he says it is a go I spend a little time with the die grinder, files, sand paper, and surface conditioning discs. On a SBC the worst casting flash is around the oil filter boss and left front corner of the block. I typically spend three or four hours on the block and another hour or so on the heads. I have never completely polished a block but the small things that I do really make a big difference.
I vote for the all-out, just because...well...do I really need a reason?
I'd like to see the Hot Rod build myself. 'Cause I like hot rods. Also streetable motors are more long-term fun than race motors, mostly.
Do the all out version, but do it without spending much money on parts. See what you can get out of a mostly stock rotating assembly (forged pistons might be the only go fast part, that and rod bolts), find some good performing inexpensive heads, and cam it as big as you can, within the safe rpm limits of the bottom end.
Good suggestions so far...and I really like the idea of the 'all out' version, because I normally lean towards the conservative end of the spectrum. If word comes back that the block is up to snuff, then I can have them go ahead with machine work. Parts will be purchased as time goes by. It's not my primary focus right now, but it should be a fun project!
Any updates on this engine build? I have a 350 now, but when my 305 was running, it ran great. I guess I sorta miss it a little. 350 gas doesn't seem to go as far as 305 gas. Of course, my foot seems heavier for some reason.
i don'thave any comments on sbc builds; but whenever i see that tfeverfred posts i just can't help myself from clicking on the thread just to get another glimpse of Candy Barr.
I have a lot of experience with those old Martin Kits. Very good kits, and will work great on your 305.
What is the bypass valve set to? If he hasn't been taken apart and shimmed, the number stamped on the top will tell you the boost it is set for. Just look to see if the original stake marks still line up on the bottom of the bypass valve to see if its been monkey'd with. The turbo is a RayJay 301EE that has pretty much an identical flow map to the T04 with a V1 compressor wheel. Good to about 450hp. The A/R is stamped on the inside of the exhaust housing, at the exhaust mouth. It should be a 1.0 A/R.
I build an engine that was a mix of these two. It was a great runner.
30 over 84' L69 305. Stock block, crank, rods, most of the valve gear, and intake.
Get a set of 416 or 601 heads, mildly pocket port them and run the smaller 1.84" intake valves. Epoxy up the huge hole in the port below the rocker stud, and just smooth the epoxy out, and then port match. I usuallly get these heads for next to nothing or free. The 601's have really small 53cc chambers for more compression, and my motor came with them. Both of these heads have ports that are nearly identical to the 350 heads but the bowl is a little smaller.
1.84 valves flow as well as the 1.94's in a 305 because of less bore shrouding. Definately use the flattop pistons for compression.
I used a little 214/224 camshaft because I had it, and it worked perfect. Intake was a factory aluminum qjet intake and a rebuilt 84' qjet.
The car had long tube headers, and a recurved HEI. It ran 14.4 in a 84' monte carlo all day long, and got 22mpg with a TH350 and 3.08 gears.
I think you should build it as a mild hot rod engine. They are perfect motors for that.
I don't care what you build, I just want to learn and read your threads. You Sir, should write a book if you have not done that already. Can't wait for your next update.
What options would I have on improving a 305 if I avoided taking it out of the car? Also what would the costs on related mods be?
Since this thread has be dredged up, are there forged psitons for the 305?
Camshaft. Maximum tuneage of the carb and ignition. Correct sized exhaust (duals) for its cubic inches/cam selection.
305 engines were sadlled with smaller cams than their 350 brothers, as well as retarded valve timing in some cases. This kept them from matching or exceeding the performance of the optional 350 (in many chassis), and helped GM promote the 305 as an 'economy' V8 replacement for the 307. Putting in a decent cam...even if just a 350 stock replacement cam, with 'stright up' cam timing (new chain and gears) will wake a 305 up. Add a small four barrel and headers and you'll be happy.
Yes, although there isn't a huge variety to choose from. They tend to be pricey as well, but they are out there. I'm looking into a set for my build now, and will let you know what I'm able to come up with.
Anybody know whatever happened to Fat Hack? I see he hasn't logged on since 2013...
He is on Facebook a lot, Greg Rakowski.
Nope haven't seen him but he owes me somewhere around 80-100 dollars so if anyone does see him and he is ready to cough it up have him get ahold of me. If he just wants to whine at me then he probably shouldn't bother I can get whined at anytime.
Separate names with a comma.