I just put a new 350 into my 1990 Camaro RS, now I have a spare 305 (LO3) in the backyard that I don't want to go to waste. So I want to rebuild it. I am gonna dissassemble it myself and get the block and anything else I want hot tanked/bored/ and whatever else comes to mind.

So, does anyone have suggestions for a rebuild kit and what parts (crank/cam, etc) that I should replace and which I should keep?

I am not looking to spend gobs of money and don't want any insane HP numbers, I just want to get more wrench turning experience with an old motor... plus I like it, since I beat the living **** out of that 185K mile 5.0 slug. So I am kind of attached to it.

 

I'm rebuilding my 305 currently, it's only a temporary measuer until I get the money rounded up for my big block, but then i'm giving it to my little brother, so it's not going to waste. Anyways, here's what I'm doing to mine:
Port/polish heads, Z28 springs/retainers, Summit 214/224 cam, Holley Steet Dominator single plane intake (it was only $35, so I couldn't pass it up), steel shim head gaskets (fel-pro 1094 yields ~9.8 CR), Holley 750 DP (only carb I have laying around, but a 650 DP would be best), Holley hi-volume mech. fuel pump, Speed pro rings, ARP rod bolts and new Speed pro FT pistons (cracked one of the old ones, so I just got a whole new set), plus other odds and ends I'm forgetting.

I ran a sim on this setup and it's supposed to make like 358hp and 356tq, but that's a bit generous, Car craft did an article with a similar setup and it make 320hp, so it'll probably be around there. Cam runs out at ~6k (5.5K peak) and makes good midrange. So far I've spent like $400 or so for the whole setup, which is money well spent going from 150hp (track tested) to 320ish hp since I had to rebuild it anyways (broke a timing chain).

Oh, use the stock crank and rods, get the crank turned if necessary, and get new rod bolts put in the rods. Since you won't be putting out tons of power the stock stuff is fine.

Hope that helps you out, if you have any other ?'s, let me know.

 

Great Combo!

I just went (car 9, first time at track with combo, needs some more pump shot tuning, bad bog after a good hook)



with essentially the same setup.. only differences is that I run a torker II single plane and edelbrock carb. It has 416 heads ported and polished by myself and stock size valves, headers, full 3" all the wayback, t5, and 3.42 gears. Its crossing the line at like 6300 in 3rd needs more gear. With more gear and the carb dialed in (its pretty much there save for pump shot ) it should be on the low side of 13.5's i hope. You should be right there if you do a good job porting the heads (have to spend some time with them)

 

Forget the LO3 heads. Throwing them away wouldn't be a waste, they're already a waste. (Recycle them, of course...)

Find a set of 416 or 081 heads. They're gobs better as they are, larger intake valves and porting would just make them better. Figure on new valve springs, though.

Any other recommendations would require knowing what you plan to do with it once you get it back together.

 

Yes, take your time porting the heads, they have great potential with a little massaging. I haven't done mine yet, since I'm working on a set of 441X heads currently, but it will probably take me 20 hours or so to port/polish them well. If it's your first time, find an old set of junk heads to practice on (I found a set for $15 when I first started) and check out the thread by Sitting Bull about porting the 305 heads.

 

Let's be clear: Do not bother porting LO3 heads. They ain't worth the effort. Period.

 

i say you put all into a geo metro when finished...lol....

 

YES THROW AWAY THE Lo3 heads


just to be extremely clear on that

 

Good setup! Couple of comments though...

Single plane is better for higher RPM's, since you run out at around 6k, I would swap it for a dual plane, you should see a big torque gain. and a 750 is kinda over carbeureting a 305, but I see you already mentioned that... Nice setup again...

 

I was going to get an RPM manifold, but the guy never sent it to me, so I had to find something cheap. I came across the Street Dominator and since it was a low rise single plane I figured I'd try and if I didn't like it I could swap something else on since it was only $35. I do agree that the 750 is too much, but I don't want to spend money on a carb when this one is laying around collecting dust, besides it's almost brand new.

I also agree that the LO3 heads are junk, they're best used for practice porting and to see how far you can go.

 

To the original poster, if you're just looking for experience, and don't have a use for the engine, I don't think I'd spend the money to rebuild it.

For the experience, maybe strip it down, mic everything, learn what the clearances mean, etc, then reassemble it and fire it off on stand and see how well you did putting it back together.

If you have ideas of selling it when your done...don't take this the wrong way...but I think the majority of folks would rather buy a rebuild from a Discout AP store, than from someone who just did their first engine.

Note: If it were a 350 or larger CI engine, then I'd say go for it.....only because you have a 350 now aqnd regardless of what performance parts you put in a 305 (within reason) even the mildest 350 build would out do it.

 

i say if ya got the money to do it without gettin crazy..then rebuild it and have fun with it...if you want to change something..then do it..if you want to start completely over ...go for it...


just have fun

who knows you might build youself a decent motor..


and 305s arent that bad

 

Some of you get me, others have missed the point, but it is my fault for not elaborating...

My Camaro is my first project, and I have more porjects lined up after I complete it and I would like to do most, if not all of the work myself one day. I'll be graduating college soon and have some pretty good jobs lined up, so I might actually start making enough to afford my little hobby.

Anyway, since the new engine is in the Camaro, I ahve the old one just sitting there, and I don't want it to go to waste and wind up with a yard collecting engines and parts. I want to take it apart and learn how to build them myself. I also want to get a little bit more power out of it, and make sure that it can run right for a long time. This way, I have a working small block sitting around. So... if there comes a time when I am swapping motors, or a motor goes down, I could use this heap in the back of my shop as a temporary motor to move any vehicle (most of my plans involve SBC's) when the project motor is being rebuilt, make sense? Or am I absolutely crazy?


So, as both a learning experience and extra engine sitting around, I think it would be worth it for a nice rebuild kit. So I should keep the crank (duh) and the rods. What about the pushrods? I am thinking it would be a great idea to replace the cam, and the intake is a must since I will be running a carb and not the TBI unit. heads I can leave stock for now. My current 350 has Vortec heads, which I will be replacing with AFR's when I get some more money. So I can swap over the vortec heads and take care of the compression loss somehow.

Am I forgetting anything?

 

I'd keep the stock crank and rods unless it's going to see abuse, then I would have the rods reconditioned with new bolts, but that's almost as much as a set of new 5140 forged rods (~$150 on ebay), so you might as well get new rods. The crank will be fine, but you can get a cast steel one for ~$150 on ebay if you don't think it will hold up, or if the crank needs cut it's only a bit more for the new one. Don't keep the pushrods, they're only $28 for a set of Comp Cams Magnum pushrods from Summit. I would suggest replacing the cam since the one in there is weak. Summit has some cheap $80 cam and lifter kits that would work well. You'll need some Z28 springs and retainers with the new cam, you can get those for $30 on ebay. The intake will have to be a vortec style intake since the ports are raised, and you'll have to buy a different intake when you get the AFR's since they use the standard pattern. As far as the compression loss, there's not a wholelot you can do. You can either get FT or domed pistons, mill the heads (not reccomended) and or get a thinner head gasket. Fel Pro 1094 has a .015" compressed thickness and will raise compression a little less than half a point.

I think it's a good idea to have a backup motor. I've needed one many a time, but didn't have one so my car has been sitting in the barn for weeks for whatever just broke to get fixed.

 

Edit: I was looking at the graphs for my motor the other day and noticed the cam runs out at 6.5k and peaks at 6k.

 

Since this thread was already going I have a few questions. 416 or 081 heads, what year cars and engines would these come off of? I go to upick often . I don't want to do the lower end so compression would be a factor, but can have the heads milled down.

Should I go with a 350 l98 cam, junk yard parts are cheap? I have a street dominator intake (300-48) will this fit under my hood with a tbi adapter and drop air cleaner? I plan on nitrous down the road, can you mount a holley spray plate below the tbi adapter?

Thanks, sure some of these are stuff already around but I did a search on street dominator and did not find much except this thread.

91 bird 305 5 speed... 86 front end on it now 122k strong

 

Ok I've reading some past post's looks like the 416 heads are not center bolt. Have not been able to tell if the 081 heads are center bolt or not, hopefully so.

I'm just making a guess here that the crappy swirly heads are on TBI and the better heads are on TPI, but maybe I'm off. But the casting number should be on the heads when I go to u-pullit.

Been reading on cams and the zz4 cam is being used by some people on a 305 but some have said the .5 lift is too great for stocks heads. Is this also true for the 081 heads? and is there something that can be done to reduce the lift and still use the zz4 cam. How can I identify a zz4 cam and the salvage yard? If not what other junk yard alternative is there for a roller cam.

 

No, 416's aren't centerbolt, I'm not sure about the 081's though. You don't want the heads from a TBI, they're swirl ports. Let the junkyard keep them becasue that's where they belong. The better heads came on everything but the TBI's basically. The ZZ4 cam would be too much unless you modified the heads for that much lift, but that gets to be exspensive and not cost effective over a set of aftermarket heads. You probably won't find a ZZ4 cam at the yard since they only came in GMPP's ZZ4 350. Most people go with the LT1 cam for their roller 305's. It seems to work well and still gets good low and midrange power. LT1's came in 93-96 fbody's (I think, correct me if I'm wrong).

 

Thanks, that was the info I was looking for.

 

kfoley, 97's also had LT1's.

 

Thanks Cole, I'm not up to date on my 4th gen info...

 

I found some 416 heads on ebay for $110 complete including shipping is that a ok deal? They are out of a 83 monte carlo, that the seller claims did not smoke. my block is a 91 305 will they just bolt up? or do I have to do some modifications, different pushrods.

It would be cool if they just bolted up then I can get some cheap chrome valve covers.

Thanks

 

You won't have to change anything to bolt the 416's on (except for springs if necessary). I think $110 is a good deal as long as they're not worn out and have burnt/warped vavles and such. Do a little port work on them and they'll be great heads for the money.

 

Picked up a lt1 roller cam off of ebay for $75 including shipping
Here's what I have into my car so far...

I need to get a tbi to holley adapter the cheapest one I have found so far is $65 does anyone else know where to get one cheaper?


So I will have a projection intake, modified tbi, 416 heads ported, headers and lt1 cam. With the right exhaust and computer tuning what HP should I be making with this setup on a 305.

Thanks