Lil 307 that could....

[screamin_c10]

So the valve guides on my 307 are shot...blows smoke after I crank 'er up for a few. Lifters are tapping as well so I figured I would gather up some of my spare parts from other builds and hop up my little "boat anchor"

Combine these ingredients...shake...stir... and see what happens:

Short block is my '71 307 sporting flat top 4VR pistons @ .025 in the hole, no ridge and decent oil pressure so I'll run 'er as is.

Bone stock set of Vortec 906 castings that have been rebuilt to stock specs, nothing done but tanked, valve job, and new seals.

I also have a Summit stage 1 Vortec intake (Performer knock-off) that is needed for the Vortec head swap.

A Summit K1103 cam kit 214/224 @.050 and just enough lift to stay safe with the Vortecs

A Cloyes double roller chain set at 0 degrees

I'll re-use my Eddy 1406 as it is in great shape.

My goal is to build up this little 307 and eventually swap it into the wife’s Malibu....

Desktop Dyno 2003 shows this combo will pull ~350/350.... We will see....

[Hubscrub]

good luck, i like the little motors they get so much hate

[QKENUF4U]

307 is the only motor that lived more than 2 weeks below my buddies 6-71 blower in his 71 pro-street.. blew up a 383 and 350 in 2 weeks time... the 307 was a RUNNER !!

[screamin_c10]

Starting Point:

[special-K]

That sounds good!I built a hot little 307 once on a budget.It needed no machining...and I had it hot tanked and checked it out.They seem to hold up really well.The timing chain had gone out and the valves bent.I put .194 350 heads,RV cam/lifters,stock 4bbl intake,little 450cfm Holley,HEI,dbl row timing chain,bearings,rings...the thing ran out like a healthy 350 my K/20 with 37" tires and 4.57 gears.It was a work truck and carried a lot of weight.The best thing was,not only was it peppy but it got 13+ mpg.I'd like to see what Vortec heads would do for a small mouse.

[screamin_c10]

One thing I have always found fascinating is how fast people dismiss the 307 as a viable street motor... If you are looking for a good cruiser with decent gas mileage and a little bit of balls then why not build what ya got? I guess its easier to toss it if its worn out and replace it with a crate engine but where is the fun in that....

Just the other day I was getting fuel when a guy comes over talkin' about what a cool truck "sounds mean is it a big block?"... Once it sunk in that it was a 307 he looked a bit disappointed....I thanked him for the compliments, paid for my gas, idled out to hwy 30 and destroyed my back tires til I let up at 45....

But those days are over for this lil mouse, once I get her built, running and tuned I'll be dropping her into the wife's Chevelle to live out the remainder of its days under a slightly less aggressive right foot

[redbaron69]

nothing wrong with a 307. glad to hear you showing it some love let us know the end result. i got one i gonna use in my 70.

[screamin_c10]

Well for such a wimpy little mouse she's putting up one hell of a fight....First off the damn exhaust manifold bolts decided to seize up in the ramhorns necessitating a sawzall and a few "colorful" words of persuasion to aid in their removal. Now the studs at the pipe flange gave up with no issues, yup snapped right off All 16 lifters are slap a$$ stuck in their bores...tool is on order from Summit. Cam is wedged in place by the lifters so it wont budge...

On the flipside the bores look awesome for 40 years old, no ridge or scoring. My plugs were a nice tan color, oil pressure was good so I'm cool leaving the shortblock as is.

Ordered up some .021 steel shim gaskets so my quench will be right at .046 with a SCR of 9.0:1, very pump gas friendly.

Obviously If I am going to go to the expense of machining and building a new shortblock it will be a roller 355/383 880 block. I just want to see what this lil mouse can do on a serious budget.

[screamin_c10]

Well the Vortecs are on the 307, new cam installed, rockers adjusted, intake on, HEI stabbed, chain and sprockets set to 0 TDC, carb and wiring hooked up.

Just need to pop on the timing cover, plugs and wires, w/p and accessories. The ramhorns are in pretty bad shape, still trying to figure out how to get the studs out so I can run them for now. Gonna go to headers and a 2.5 dual system once spring rolls around....

Its gettin' down right cold here, if the weather allows I should be able to crank 'er up next weekend....

Spent a couple hours in the warm shop doing the jeep fan upgrade as well. Came out pretty good if you ask me.

[Hubscrub]

very nice

[CheyenneShop]

Looking forward to how she turns out - looks great so far.

[Captainfab]

Yes I agree that the 307's have gotten an undeserved bad rep. The guy that first showed me how to build a small block had a well built 307 in his Jeep. 11-1, 2.02/461 heads, good sized solid lifter cam, etc. That thing was pretty impressive. I've been around a couple other mildly built 307's since. I've actually given some thought to building one my self......I've got a short block in the shop. I'll be watching this thread to see how this one turns out.

[screamin_c10]

Done...well almost, still need to hook up the exhaust to the ramhorns and swap in the temp sensor from the old heads...plan on crankin' her up in the a.m. it got too darn cold to mess with her much more tonight...

[screamin_c10]

As soon as I scrounge up a serpentine crank pulley I'll be swapping over to the same setup I have on the Chevelle....hence the un-painted nasty brackets...

[nickp51chevy]

Good to know that an ol' lil' 307 is a great engine. I'm gonna build one up for my '51. I was just going to put a set of 305 601 casting heads on it. That should give me just a little bit more compression , and that will probably be all that I do to it. I don't know for sure though. I think it would be cool if you came up to the Monroe swap meet so we can hear that little beast.

[Captainfab]

Oh! the anticipation

Are you guys getting that Arctic air over there too?

[oldblue1968chevy]

hey man, i see your runnin centerbolt VC's too..

My bolts leak oil around the head? do yours have a lil rubber seal or anthing?..

other than that looks good dude! i didnt know you coudl put vortecs on other engines too

[rsavage]

Looks good. Waiting to hear how it runs.

[Jacfourteen]

I'm waiting to see how it runs!

[brn agn]

My natural tendency is to root for the underdog! I'm anxious to hear how this one turns out.

[Hubscrub]

i have always been a supporter for the "little motors" they have served me better than any other.....

[screamin_c10]

Originally Posted by Captainfab

Are you guys getting that Arctic air over there too?

Yup, its gettin' down right nippley...

[LONGHAIR]

Originally Posted by screamin_c10

All 16 lifters are slap a$$ stuck in their bores...tool is on order from Summit. Cam is wedged in place by the lifters so it wont budge...

Have you had this thing running yet? I would be at least slightly concerned about the lifter situation....mostly about why they were stuck? and how hard they were to remove.

I would never pull them out through the top.....and I wish they would quit selling those rediculous tools for doing it. All it does is destroy the inside of the lifter bore, which causes oil pressure issues.
Then comes the other thing, what was keeping them from coming out? If it was just carbon/gunk build-up, it's not so bad, except that is probably everywhere inside the engine. If it is from a metal burr....that comes from wear against the cam...and that means metal particles have coated everything inside and tears up the bores even worse. Neither of these is good for a new cam installation.

I wish I had seen this a few weeks ago...

[screamin_c10]

It was crud / carbon build up on the lifters. The original cam had 3 flat lobes so I know the engine is nearing the end of the line. If it lunches then I will be building a mild roller 350 and laying to rest my beloved ol' 307. Basically this is a "will it work?" type of build.

If it fails I'm out $120.00 bucks for cam and head gaskets. But I least I can say I tried it and it was a blast while she lasted...

Now mind you this engine ran smooth as glass and idled @ 700rpms. Blew no smoke other than fire up and made no noise with great oil pressure. HOW? I have no idea...three flat lobes at least 2 different brand lifters, Huge slop in the T/C and an almost completely restricted passenger side ram horn. Still boiled the tires and was a blast to drive, hence her name "Screamin'" I'm gonna let 'er go out in a blaze of glory...either today or down the road when she finally gives up the ghost... Time to go fire her off and break in the cam...wish me luck.

[nickp51chevy]

I'll bet that thing will keep on runnin' like a champ, and you'll never break it Good luck.