SBC rebuild

[MerCrewser]

Anyone have a ball park idea on how much it would be to rebuild a 327 small block? Also, is there anything else other than brass cast/freeze plugs needed for marine service?

My 1969 Chris Craft has a cracked block and I have located a $300.00 1969 327 long block on Craigs List. Think 300 is to much to pay?

 

[Chris]

Most of the clearances in a marine engine are different. Since you'll likely run raw water cooling you'll need a larger piston to wall clearance. Since the engine will run continuously at two to three times the speed it would in an auto, the main bearing clearances should be a little bigger. The valve stem clearances need to be larger as well. Those sustained elevated RPM operating conditions makes the exhaust valves run hotter which means more expansion and the cold water in the heads means the guides will run tight. That means stuck valves hitting the pistons, the heads snapping off and blasting a hole thru the domes and probably breaking a cylinder wall.

For $300, you might get a rebuildable long block. Or maybe a pile of useless junk. I wouldn't expect to get an engine that would be in good running condition- for a car. Marinizing it is a whole different story.

 

[MerCrewser]

maybe I should just go Jasper?

 

[Chris]

If this is a low-perf engine, I'd look at a local automotive machine shop to repair what you have. Your crank is probably good (although it could be a small-journal crank which makes the block a tough find)

While you have them apart, you absolutely need to check your exhaust manifolds. A big percentage of marine engines are destroyed by leaking manifolds. Have them pressure tested and then split the risers off and reseal them.

Don't get carried away. Most likely the transmission in the boat is not rated for much over the 175 horse that 327 put out. If you have the urge to put a warmed-up 350 in there, be prepared to upgrade the trans.

 

[MerCrewser]

Yeah, I'll be doing new manifolds. I had cleaned and pressure checked them, they are original!! I'm sure there are still some blockages though. Elbows are new.

Trans was rebuilt and is rated for 260. I just want to keep it stock and simple. Block is cracked and I'm broke and boat has been sitting in the shop for the past 2 years. I just want to use it again on the cheap, but I'd like to do things right.

 

[HaxbySpeed]

A lot of Chris crafts actually have a decent, heavy duty closed cooling system. They also did lots of interesting things like run the engines backwards with the transmission coupling to the front of the engine rather then flywheel, with a common oil pan linking the tranny and engine.. And even in a single engine application they are usually a reverse rotation. Instead of going through Jasper or someone else, you could just buy a brand new base GM Marine replacement long block for under 2k. Just make sure it's spinning in the right direction.. :sifone:

 

[MerCrewser]

Its a left hand motor, flywheel forward like you mentioned. A "Q' engine. Where is the best place to by a New GM marine? And what years would be the same as my 1969 327? I'm just afraid that the block may be to different to make the "Q" modification and then I'll be stuck. I dont have a whole lot of experience doing this. Bottom line is this: I'm scared I'm going to get started and order expensive stuff, and then the whole thing will go to hell, I'll run out of money and be SOL.

 

[HaxbySpeed]

Ya, they don't make it easy with lots of oddball proprietary parts that aren't made anymore, but the basic engine block is the same as a 350. I've done a few of them and have some good sources for parts. Shoot me an email or give me a call when I'm in the shop tomorrow morning and I can probably help you out. Alex

alex@cannavmarine.com
604 315 0570