Like any build should be I'm building this around the heads that I've been working. I finally finished them up so I am ready to get it going and try to have this together before the end of the season.

The heads were 172cc last time I measured but I touched them up a bit and estimate no more then 2cc more and that's high balling. The focus while porting was taller runners with the longest transition from roof to bowl I could make, long smooth radius. You can see in the pictures how little time I spent making the port wider.

I have a 86' 305 block on the stand now it needs cam bearings and the crank will need turned to do what I want. It would probably live in a stock rebuild but that's not the deal, this is a "extra car" and wouldn't even get driven if I wasn't doing this.

What I have;
305 SBC with flat tops
174cc ported 416 heads w/ 55cc chambers
10.3cr w/ .015 head gasket
comp cams XE268-HR 12-242-2 (224/230 dur @.05, .477/.480)
CCC Qjet
performer RPM intake
hedman headers
full 3" mandrel bent exhaust

The pictures are big I left them that way to preserve detail.

 

couple of the chambers and bowls

 

This thing should be a lotta fun. That's quite a bit of cam will be interesting to see what it does. Those heads look nice I wish my valve guides turned out that well

 

Thanks for the compliment on the heads Drac0nic I spent a LOT of time working on them. I have searched everything I can think of but can't find a flow-bench near me. I would like to see what they can do with a 1.84 intake and also a 1.94.

For the sake of budget I'm using the 1.84 valves for now. I did back cut all of them and radius margins, the exhaust valves got a bigger radius too. If a pile of money lands in my lap before these are bolted down I will have the bigger valves put in. I already have the valves too.

Thanks to TGO member flammingford for the 305 bottom end. I was going to use the one in my Z28 but it has a cold knock that heavy oil can't cure so I'm weary of really thrashing it.

This isn't some high mileage (read high dollar) build I'm just building this just to have something to work on because otherwise it's nothing.

 

I'm trying to get this budgeted in so I can rip it down the track a few times before the end of the year and it doesn't really look like it's going to happen. I was thinking about it and if I invest into building this 305 short-block it would be just plain stupid to not invest in the heads and install bigger valves, ect.

So that leaves me back at plan "A" and that's buy head gaskets, assemble these heads as they are, and do a head and cam swap on the flat top 305 in the car now. I have all the other gaskets needed for the swap.

If I do it this way I should have plenty of time to build the motor that's on the stand right and pull the heads and have the bigger valves installed for next year.

What do you all think? I'm just building it for the fun of doing it and to play with a otherwise useless yard ornament of a Z28.

 

A running car is quicker than a non-running one. Not only that but that stuff will transfer to another engine. It's not like buying an LG4 short/long block to play with costs ANYTHING really any more. I have an L03 and an LG4 sitting here for under $100 the pair. For that price there's no reason NOT to buy one to build up for later.

 

Done well, you should find as much as 30 cfm at 0.500" just from stepping up to 1.94s, even if you don't get trick swirl-polished, undercut-stem valves. You really did hurt your results by not leaving the throats small enough to be 91% (max) of the valve diameter, so going to 1.94s will help fix that, further improving performance.
Likewise with the exhaust ports, which now need 1.60" valves.

 

so long as you stick the LG4 heads on the LO3 short block, I totally agree.

 

They are looking ALOT better than stock. 416s or 081s for that matter. Now you just need to cut the seats for some 1.94/1.60s. Both seem to work very well in a 305 head. If you happen to go the route you spoke of recently, I can't wait to see your results.

Here are mine from today, tweaking the Q-Jet, HEI, and TH350 governor and modulator...We have the TH350 shifting on its own at 5,800ish, it FLIES despite airplane gears.

Listen to that Q-Jet WAIL and the way the truck just LEAPS forward when the pedal is kicked to the floorboard half way through 1st gear!!! I know the truck still has some power on the table with the primary jet/metering rod combination as well.

http://www.youtube.com/watch?v=VxJmvWAlIQQ

 

I'm thinking the best fun per $$$ ratio right now would be put my stainless undercut 1.94 and 1.5 valves in the heads and put them on the motor in the car for now. Maybe if my machinist has some 1.6 valves I'll get those put in over the 1.5's.

That way I can build the 305 on the stand over the winter and do it right. It's a good block but with the power band this cam/head combo should make I don't trust all the stock rod bolts, crank pits, ect.

Other things I am getting is at least a S10 converter and a 87' L69 ECM.

Fast355 that truck is a real sleeper. Primer up with non-performance looking tires but looks like it pulls like a mother up top, you gotta get that thing to the track (not like I gotta tell you though eh?). I love that QJET sound, it's unlike any other carb. Have you ever had that 310 in a Fbody? I know it was in your van a fair bit ago.

 

The heads are at the machine shop boys

I'm having the stainless undercut 1.94 and 1.5 valves installed with a 30' back-cut on each valve. They are also being milled, cleaned and checked for cracks. The guy seems pretty expensive so hopefully he's worth it.

 

I'll donate a set of 1.60" if you pay shipping, and promise to leave all 16 throats at no larger than 91%.

 

Atilla you are pure class man thank you for the offer.

I'm sure it would be well worth it but this is already costing much more then I planned to spend on some cheap 305 heads. Adding in another $50 to cut for those would just make it worse. It's not completely the cost of the work but just the fact that I could be buying Vortec heads for what I'm paying it makes me feel like a bit of a sucker. Just a bit though because I really enjoy porting heads and it is one of those things that you "gotta pay to play".

We'll be able to get a good look at the work when I get them back because I'm assembling them my self and I'll take some pictures of them once I get them back. He said it should be by this weekend so we'll see. He's doing a magnaflux, cutting for 1.94's, de-shrouding cut, 3-angle valve job, 30' back cut, milling, and cleaning.

Thanks again for the offer and all your help with these heads Atilla it hasn't gone unnoticed!

 

I see you didn't specify a 75 degree cut below the 60. Make sure it gets done.

 

Here is what Atilla is talking about.

http://www.popularhotrodding.com/tec...job/index.html

 

damn that extra cut made a huge difference everywhere under peak flow on the heads in that link.

 

Do I need to specify how deep or should this guy know?

 

He should know. Some get upset if you try to specify. But if he asks, he should set it to cut just as deep as possible without hitting the guide boss at the bottom of the cut, and the bottom of the cut is when the fresh new 60 degree angle has been narrowed to about 0.055".

 

I finally got to go rescue the heads from the machine shop, I paid the ransom and brought them home.

Like always I took loads of damn pictures and nothing really turned out good enough to show you all. Apparently we have mole vision in my house because all the pictures look like they were taken in a dungeon with torch assisted lighting.

I am super pumped they look awesome I can't wait to strap them down. The **** thing is though that the drag strip closes later this month and the motor won't be done by then. It may be a good thing though because it will give me time to get the transmission and rear end sorted out. The stock stall TH200c and 2.73 rear end DO NOT play well together.

These pics will have to do until I get the lighting sorted out. Enjoy.

 

Man those look GREAT

 

Thanks Fast355 guys like you make me want to build this 305 just to see what it can do. I figure a 305 bottom end is cheap, people give them away, why not build one to thrash? good for people who are broke like me.


What is a good budget 3000RPM stall with lockup for 27 spline anyone? I'm torn between investing in that or waiting and getting one for the 89+ 700r4 that it will eventually have because I don't see the TH200C holding out very long.


Here's one of the pics that isn't too bad it shows the bowl work and valve job good.

 

Don't sweat the flow bench. It's just a guide like a dyno. If you build an engine that does what you want it to do, what importance is a dyno number?

Same applies with flow benches.

I think if you're having a good time, keep going. That's what this is all about right?

 

You nailed it right there man.

 

Thanks...

All these "what's my dyno going to be" crap tends to irritate me..

Just have fun with it.

If people learn the engineering behind a purpose built engine and forget garbage like flow and dyno as an ultimate measurement, it is my experience, they have a better outcome, more positive about the hobby, get better results, and have a better time.

Here's something funny, one of the shops I deal with out west has a dyno no one will go to because it's 30-50 less than another one in town. He likes it that way because he only gets the serious people. He calls it the ego-killer...

 

I got the "important" measures of the work out of the way already. I took the car down the track with the stock heads and cam in it so we'll be able to see the change. Surely the cam and head swap will be under 15.5 @ 90mph, but we will see. The MPH is what I'm gauging because the shitty trans/tires/rear will be lucky to break out of the 14's.

The flow data would be nice to have to see the potential and I really wanted to see the difference it made over stock flow. I also had interest in seeing what lift they max out at.

You are spot on though, I totally agree. It's one of the things in life you win by simply participating, everything else is just illusion.

 

...in for the results! looks like a "stout" build!

 

Yeah, why I detest building to a dyno number. It's not as fulfilling or as effective.

 

Honestly its all just a guide...Even track times can be deceptive. Weather dramatically effects them. You may run a 15.5 @ 90 mph in cool weather, swap parts and run a 15.6@ 91 in the heat of summer. The DA may go from 200ft to 3,500+. You may also be running with a head wind or tail wind. All of this will effect when you cross the traps. Empty tank, Full tank, luggage in car. I ran the 1/4 today at Ennis, TX in under 500 DA, but at the same time I went into a 15+ mph head wind. I squeeked out a 13.97 @ 95.39. I got to make 3 passes.

 

You may be right but when you build a 305 you gotta have something to attempt to hush the naysayers, you probably know this more then just about anyone though.

The DA that night was 2800ft and it was nasty hot out.

 

If I hadn't said it before, good luck Doom, can't wait to see the results.

 

Here is what the 305 bore looks like with the 416 head cut for bigger 1.94 valves. You can also see how I blended the ridge made by the cut into the bowl and it looks damn good if I don't mind saying so my self.

The chamber at it's widest measures 3.843 and the bore is standard so it will need the intake valves notched into the block to make best use of them.

Also the intake valve can lift .625 before it contacts the block without a head gasket.

One of the heads is assembled and I left this one bare to see how it sat on the bore and valve lift, checking lift out of curiosity more then needing to check.

Still got a ways to go before it's all together.

 

The block got the intake valves notched into it today. I measured the sweeper cut made by the machinist for the 1.94 valve in the 305 chamber and it was 1.7 long. Using that as a guide I first installed pistons to make sure there was room for the cut and see where the top ring was and plotted out the grinding. Each one was cut to to 3.8 at it's widest edge.

Also found that the 305 I'm working on has X rods that is pretty good to know since it's going to have to spin up a bit to do what I want. Having had a few SBC's guts spilled out on my work bench this is the first I've actually seen them.

 

A 305 having X-rods is not really a surprise to me.

 

I've taken 4 Fbody 305's down to bare blocks and have never seen them before Fast355.

This should pan out well if the heads flow well. Taking some measurements and crunching numbers the heads have a 1.73 Cross Sectional Area at the push rod pinch and that is perfect for a 305 @ 6100RPM. With the comp XE268 and Performer RPM intake that is where I should be making peak HP.

With the holidays coming it doesn't look like this is going to be put together any time soon. Maybe Santa will bring me a turned crank, oil pan, full roller rockers, ARP rod bolts, and head gaskets though.

But I could do a head and cam swap on the 305 in the car now and build up the 305 right on the stand over winter.

 

My '86 LG4 had X rods.

 

The 305s I pull down are the LE9 models out of trucks/vans. The only 2 piece rear seal 305s I feel worth wasting my time with. The others have weaker cranks, weaker rods, and harder to work 434/415/416 heads. I have seen the factory 305 truck engines with forged cranks, 4 bolt mains, and X-rods.

As for the HP peak I am going to guess it will be around 5,800 rpm with that cam and intake manifold. It should have a relatively flat HP curve from 5,500 to 6,500. With the proper valve spring pressure, with X-rods (arp studs), balanced rotating assembly, and Z/28 oil pump spring you should have no problem shifting it at 6,300-6,500.

 

man them heads look great i cant believe you did all that port work yourself. i been thinking about porting those 305 heads i got myself but im worried id mess it up

 

Looking at the bearings that came off the 305 core I would guess the balance on the crank is good. The only reason it needs anything done to the bottom end at all is because it was left in a shed by the previous owner and something spilled on the crank and rusted. The core is from a 305 IROC with 30k miles apparently.

I have a Melling M55 and a MrGasket #26 spring for it so that is covered.

t.p.engineerin Thanks for the compliment I did spend a LOT of time grinding on these. I probably spent 5x more time doing research and observing.

The best thing IMO is to start small and do a basic stage 2 type porting where you don't redesign the port you just blend ridges and streamline the valve guide and size the port opening. You can do a set of heads in a weak end with this method and they will be better then any stock SBC casting when you are done if you cut for bigger valves before you start.

Work a small section in one port and then go down the line doing the same to them all, do this repeatedly.

And getting a junk head to test your hand out on is a great idea.

 

i might try it one day i think ill do a practice run on the swirl port head when i get them off then find another set to actually do it on i guess the trink is to keep from gouging the ports

 

That's the way to do it ^^ practice on a junk head. For what you are looking for you don't want bigger ports, you just want them cleaned up.

I got the rockers scratched off the list of needed parts and started tearing the 305 that's already in the car apart to go ahead with plan B.

The rad, intake and all accessories are off and headers unbolted. Just need to take the heads, damper and timing chain off tomorrow.

 

I didn't have much time today but I got one of the heads off.

Look at those puny bores, don't you just want to slap the bastard?



Here's something you don't see too often. A CCC Qjet on a Performer RPM. They are well acquainted it's been on my daily driver for years. Soon we'll make good use of them.

 

OLD thread, but I just started reading this and it ended with no conclusion.
Does anyone know if this project got finished and/or how it worked out?