Inline six rebuild

[KVB]

Hi all,

I have a 1965 GMC shortwide with a 230.

I am in the unique spot of having some extra cash. wahooooooo

I want to rebuild the six cylinder by myself. I am mechanically inclined, and have different books and manuals on hand.

I have no previous knowledge about the condition of this motor.

I want a daily driver with a little different motor under the hood. I have a set of long tube headers, I have an offenhauser manifold, also an HEI distributor.

I am thinking about a mild cam, how do you select a cam?

What size of carb?

To make sure the block is good, i am having the block cleaned & magnaflux.

What else should be done on the block while it is at the shop.

Eventually, the transmission will either be a 5 speed manual, or a 4 speed auto.

Will it be sufficient to lap the valves, or should the shop do some work with the head?

I am just looking a direction to start with. Any help is appreciated.

Ken

[TJ's Chevy]

For a daily I'd keep things mild. Have the block and head checked for cracks and magnafluxed like you had mentioned, good honing, I would personally install new valves. Mild cam won't hurt a thing. I'd suggest something like this:

http://www.compcams.com/Company/CC/c...x?csid=59&sb=2

This cam has more lift, but will help keep the power more in the mid range. Not to radical. You will need to upgrade the valve springs as the stock ones will only support up to .450 lift as this cam is at .474.

A good carb would be a Holley and I would Highly recommend doing this mod to it. https://www.youtube.com/watch?v=iXdFLCIz-BA

A 600 with the mod and jetted down would work nicely for that application. Lotta guys are gonna say 390, but it's a rip off unless you can find a good rebuildable one. And in the video Tom will describe why taking one primary away Really helps. Hope some of this info helps! If you have any questions be sure to ask.

['68OrangeSunshine]

KVB: If you're not aware of it, you should get a copy of Leo Santucci's book, "Chevrolet Inline Six Cylinder Power Manual." He outlines several key points and issues when rebuilding a "Late" Chevy L6 [230, 250, 292].
TJ: What don't you like about the 390 Holley? The price? At $476.95 for the 4160 version, 0-8007; and $609.95 for the 4150 0-80507 -- I'd have to go along with you.
I ran the R-8007 on my 292 from 1979 to 2002, but I paid $82.07 for it new, then. After a rebuild on a different 292, that carb ran OK thru the 500 mile break-in, then went erratic. We figured the throttle plane might've warped over 25 years, so I just got a new Edelbrock 500 CFM 1404. I prefer the AFB design, personally, as I find it a lot easier to work on than Holleys. Economics was a major considertion. The Edelbrocks cost much less.
[I found myself placing my old 8007 on my Offy intake to check control attachments, in case my 1404 was sidelined for missing parts. When rebuilding the Performer this week, in rustic conditions, I managed to lose a high idle cam/choke linkage in the dirt and didn't want to run an incomplete assembly. But my local High Performance vendor, Don's Hot Rods, comped me a replacement linkage. So I'll be OK.]
I remember putting a 50cc accelarator pump kit on that Holley, and it would stomp!
Great T. Lowe video, that guy's amazing. He's a big contributor to the forum at Inliners International's website:
www.inliners.org
Anyone thinking of building a Chevy L6 would be well advised to check that site out.

[TJ's Chevy]

Hate the price for sure, And the fact you don't have a manual choke option...unless somehow I missed it.
Thanks for bringing up Leo's book. lol I own it and can second the need for it...Lot's a Great info there.
I have a 600 holley that I rebuilt, but it has been giving me tons of trouble. lol I was hoping to buy Tom's kit and try this on my 305 V6, but I'll have to figure out what's wrong with this carb first.

[KVB]

Guys, thanks for the replies.

I just picked up a holley 600 yesterday. Needs a rebuild kit, but for 50.00$ I thought it was a good deal.

When the head and block are at the shop should I have the valve seats recut? or is lapping the valves sufficient

Do I have the block specs checked. I am mechanically, but do not have the speciality tools for checking the roundness of the cylinders.

When they clean the block, I imagine it is a bath of some kind, what will happen to the surfaces where the camshaft test?

Is it necessary to have the "bushings" replaced?

I have leo's book, and will check out the inliners.org

[TJ's Chevy]

Originally Posted by KVB

Guys, thanks for the replies.

I just picked up a holley 600 yesterday. Needs a rebuild kit, but for 50.00$ I thought it was a good deal.

When the head and block are at the shop should I have the valve seats recut? or is lapping the valves sufficient

Do I have the block specs checked. I am mechanically, but do not have the speciality tools for checking the roundness of the cylinders.

When they clean the block, I imagine it is a bath of some kind, what will happen to the surfaces where the camshaft test?

Is it necessary to have the "bushings" replaced?

I have leo's book, and will check out the inliners.org

Unless the motor had 350,000 on it a honing should be fine. Most of the time to lap valves you will have to cut the seat or they won't seal right. I've done several small engines and that's been the case so I don't see how a bigger one would be different. But if they aren't worn to bad they may be ok...pending on mileage it's a toss up. lol But you want a dependable driver...I'd do Everything while the motor is apart. Your going to want a new camshaft. And yes, you'll want new rod, main, and cam bearings. I'd recommend Clevite.

['68OrangeSunshine]

Originally Posted by TJ's Chevy

Hate the price for sure, And the fact you don't have a manual choke option...unless somehow I missed it.
Thanks for bringing up Leo's book. lol I own it and can second the need for it...Lot's a Great info there.
I have a 600 holley that I rebuilt, but it has been giving me tons of trouble. lol I was hoping to buy Tom's kit and try this on my 305 V6, but I'll have to figure out what's wrong with this carb first.

I put a manual choke kit on my Holley. I think it was a Holley kit, too, but they also used to sell generic conversions in the ''Help'' section. I put a generic unit on a 9635 Carter AFB 625 CFM I ran on a V8 454 in a '67 Suburban.
I like manual chokes -- they work when you want them, and they don't go on when you don't need them. Sometimes radical changes in altitude, and steep declines in temperature would trigger the auto choke just when you didn't need any unexpected changes in performance. Like driving around the valley floor at 100*F and then taking a road up into the mountains [where it might read 32 - 50 *F].

The one gripe I had with the Holley system was the power valves. One good back fire and you were out $5. Now it's $10 or $15. I usually idled at 17" Hg, so I used the 8.5"Hg power valve. The value of the power valve should be 1/2 of your operating idle vacuum draw.
The Carter AFB and its clone, the Edelbrock 'Performer', use degreed springs and metering needles instead of a power valve, so a hearty backfire doesn't mean you need to R&R the carb, disassemble it, change out power valves, reassemble it, remount it and retune it.

[TJ's Chevy]

Originally Posted by '68OrangeSunshine

I put a manual choke kit on my Holley. I think it was a Holley kit, too, but they also used to sell generic conversions in the ''Help'' section. I put a generic unit on a 9635 Carter AFB 625 CFM I ran on a V8 454 in a '67 Suburban.
I like manual chokes -- they work when you want them, and they don't go on when you don't need them. Sometimes radical changes in altitude, and steep declines in temperature would trigger the auto choke just when you didn't need any unexpected changes in performance. Like driving around the valley floor at 100*F and then taking a road up into the mountains [where it might read 32 - 50 *F].

Exactly! Manual chokes are much better imop.