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'65 #sMatching--Small Block Engine Swap to What? LONG!

Joined
Jan 12, 2004
Messages
50
Location
Clinton Twp, MI
Corvette
1965 Corvette Convertible
Well, I'm bummin'! I've tore the top half of my motor down this past week. She's a #'s matching 327/300 that over the past 3 years I've converted to, visually, look like a 350 horse...correct '461 intake, 2818-1 Holley, had the script valve covers on her when I bought her. I decided to make her into a solid lifter, correct for that 365 horse look. Well, I noticed this past year she started to drink antifreeze so I decided to pull the heads in the cam swap process and discovered the repair in the right head (original '461's) had let go (was done 6 years ago) and antifreeze was seeping out of the #1 exhaust valve (she was all caked over in a white substance).

Dilemna: I may have a cracked block...#5 cylinder and #4 cylinder has sludge evidence on the cylinder walls in the valley side. This will be closely examined by magnufluxing the block. I had already made up my mind to mothball the good head and the repaired head and had just ordered a set of Dart Iron Eagle 180's w/64 cc's. My 2818-1 carb has been in the hands of Jerry Macnish for a rebuild/replate).

A trusted engine builder and family friend was over last night to give his take of some vertical lines on 2 of the cylinder walls. His view was it would make sense to pull the block and disassmble it. That's when he noticed the sludge buildup. He would degrease it and lightly hone it out recognizing the block had been bored out .030 over and new pistons were put in 5 years ago. Well, if it turns out that after magnufluxing the block she's indeed cracked, I've made up my mind that I'm going to mothball this block and turn towards a replacement... WHAT?

Seriously, I'm really liking to keep that "stock look" and considering I've got a good start on components for the "365 horse" look (8" balancer, carb, intake, 5 quart pan, windage tray, LT1 cam and edge orifice lifters, sticking with the factory rams horns and side exhausts...I know the heads aren't right but that is what I'm giving up...going modern.

I'm really concerned about going after another 327 block...no history and you pays your money and takes your chances. The idea of just throwing good money after bad comes to my mind. So what would you do given my original goal to keep that somewhat nostalgic look with a lot more "balls"? Buy a long block, if so what would be compatible with all my components? Shelve this whole idea, money be damned, and spring for a crate motor, which one? I've done some reading tonight on issues of the crankcase vent tube, flywheel changes, rams horn manifolds bolting on. What other issues are there?

Maybe I'm just hung up on the fact that, if she is cracked, I've lost a big chunk of originality. I suppose I shouldn't complain, I've had blast with her so far.

Your opinions/experiences appreciated...let her rip!

Thanks!
 
If your mechanic can magnaflux your existing block, he could magnaflux a different 327 to make sure you get a good block. 327 blocks aren't just lying all over, but you can find them. Personally, I had my 327 rebuilt although it really didn't need it, instead of going with a crate motor. But a crate motor does have it's advantages. As far as heads, I have one word-aluminum.:D Classic
 
Jim, if you want to stay with a 327, there are plenty of #2870 327 blocks around (Tracy, Paragon, Engines Limited, etc.); if that's not a big deal, 350 blocks are a dime a dozen, and they're everywhere. There are workarounds for the PCV with a late no-hole block.
:beer
 
Classicvette63: You're right. Testing out a 327 block should not be a big deal. I'm just a little gun shy of these 35+ year old blocks that have been through a lot. I'm with you though. I lean for the nostalgia look (must be showin' my age)! Thanks!

Hey JohnZ: Yup, know those sources well...on a first name basis with Dennis. If I ended up with a 350 block, are there better years than others? This next question would probably be answered by the engine builder who came over to my house and that is: Is there any chance the internal components would fit into the 350 block from my 327?

Thanks again guys. Keep the ideas goin' as I'm already leaning toward that nostalgic look with the carb being redone (realize the heads are my giveaway...at a glance they'll be orange!)

Jim
 
if you can find a large journal 327 crank you can use a 350 block, but there is no substitute for cubic inches and since you are not interested in being correct just looking correct the 350s are all over the place. :cool
 
A stroker 350 (383) might be nice - you see them in the magazines for around $4000 with all the goodies . . . over 400 in hp and torque
 
bossvette & rowingone,

Thanks for the suggestions but I'm trying to keep the costs down and since my original block was rebuilt 6 years ago, and currently has roughly 15K since the reuild, I'm trying to resuse the pistons/rods etc. in this "hunt". Yeh, a stroker would be a hummer in this 3,000 # '5.

I remember a thread about a year ago where the forum member just had to step out of a brand new built stroker 327. If memory serves me right, he was asking $4,000 and I believe it was pan to carb. Quite a deal at the time (and for now)!

I took a 2nd look at my specs on the original block and she has the date code of B165 with specs as assembled of FO302HF (which is one above the base 327's offered in '65 (300 horse) mated to an M-20 4 speed.

I'm thinking the block date code should be in the September, '64 through February, '65 range. Obviously, Nervanna would be an HF code block, but since I'm going to convert to a 365 horse version, an HK or HL or HM code would work within that date range.

Thanks again.

Regards,

Jim
 
Have you given any thought to repairing the crack? There are several methods to do this including welding, drilling/tapping/plugging. You can then save all your engine internals and re-use them.
 
Mike: I'm hoping my original block checks out with no issues. But, worse case scenario, I'm looking for a replacement block. You're right, depending on where that crack is, my understanding, it could be repaired and I'm off and running again...back to my simple cam swap. We'll see as I'm just about ready to pull the motor.

I spent on and off this weekend (more off then on) removing all the hardware supporting the engine and trans. Right now the motor''s still in the car supported by the jackbridge/floorjack with a block of wood while the tranny is just resting on a tranny jack, totally unbolted from the bellhousing. Just ran out of gas. Plan on pulling both tomorrow night.

I hope to know the status of my block this week.

Thanks for your input. We'll keep you posted on my project.

Jim
 
Had to chime in hear and share my good news. My original block is OK...NO CRACKS. :m Found out today at 11 a.m. What was looked at carefully on the valley side of the cylinder wall of #4 & #5 was a decided shineyness to the casting. Could suggest a porosity issue at the time it was cast. In any event that can be lived with.

The enginer builder stopped off last night and we dismantled the oil pump, all the pistons and the crank.

Boy, something had let go in the approx. 15K miles since my rebuild. Most of the rod bearings had that copper look. The pistons were in good shape. The cylinder walls has some light vertical lines on a couple of cylinders. That can be mostly honed out.

That's the good news. Seems my first rebuild had issues I wasn't aware of which necessitated the rod bearings be .020 and the crank bearings be .030. It's my builder's feelings that "sure they make .040 bearing, but I wouldn't want to use them in this application." I kinda agree. So, I'm replacing the crank. The original crank # is a 2680 and I'm in luck 'cause the shop has a #4577 which is also a forged casting, small journal crank used back in the '60...not necessarily in a Corvette 327, probably a pass car. But, if that crank checks out (he believes it's turned for .010), my only downside to this is I'll have to have the components rebalanced. We're getting into the racing season so they may be backed up a couple of weeks on this.

One thing I'm changing when I break in this motor is I am sticking with dino oil. On my first rebuild I started with dino oil but switched to Mobil 1. I think I switched a little too early as my rings really never seated. On average I was getting 500-700 miles to a quart. And, I was still changing the oil every 2500 to 3000 miles. Dumb!

When it comes time for breakin, I'm going to revisit the archives on proper breakin and let that be my guide...using dino oil for good.

I'm going to be a busy boy when all these components come together in a few weeks. This Cruisin in Auburn, Indiana could be a stretch goal for me. We'll see.

Hey, thanks for "holding my hand" on this one. I'm really glad that factory block is OK.

Jim :D
 
Good to hear your block is Ok, are you far from the Ohio border? If not and you need a hand let me know I may be able to swing it as I am ony about 12 miles from Mich.
Craig sr.
 
bossvette, thanks for the comments AND the offer of help. This car is like a magnet...my neighbors just come over anytime I'm wrenchin' so I'm never lacking for help. I do appreciate your offer. By the way, I'm just 20 miles north of Detroit. This putting back in the car is more prepping the components as welll as cleaning up the engine compartment...that's taking the time. I'm fortunate to have a 4-post lift. Made the tranny removal a snap.

I'll keep you posted on this project. My goal is to have her debugged B/4 the trip to Auburn...we'll see.

Thanks again.
 
Jim, if the replacement crank doesn't already have the snout drilled and tapped for a balancer bolt, have your shop do it; most 60's cranks weren't drilled. Assuming you're using new rings, make sure they're moly-faced, not chrome-faced - the moly-faced rings seat a LOT faster, with the correct hone finish on the bores.

:beer
 
JohnZ, Thanks for the pointer on the rings. The builder mention sealed power but not the type. I'll be sure to ask him about this.

Thanks again.

Jim (6T5RUSH)
 
JohnZ,
The post about the crank snout forces my question:
My 68 327/300 is drilled and tapped but I was told it does not require a balancer bolt. Whats the real deal??

6T5, glad your block is OK......
 
Harmonic balancers are primairly fixed by an interference fit -- in other words, the press fit is usually enough to old them on. The 6" balancers did not have a bolt because they are small and the engine applications are typically not high performance.

The 8" balancers are also pressed on but since they were used on higher performance cars that might see 7000RPM, the bolt is added security. I recently replaced my 6" for an 8" and had the crank snout drilled and tapped - was surprised at the weight difference between the 6" and 8" balancer. Not only is the diameter bigger, the 8" balancer is much thicker.

The crank bolt and extra fat washer are still available from GM. In fact, when I ordered from gmparts direct, I ended up getting 5 bolts and 5 washers - if you need a set let me know. If I was in your shoes, I'd add the bolt and washer - can't hurt and if nothing else, it gives you the ability to turn your engine over with a breaker bar.

Brian
 
Happy Ending but a Warning

I think this is a good example of what we can avoid if we want to drive our babies. If I had a numbers matching car and I don't (everything but the block) I would rebuild the engine and store it. Especially on C2s, numbers matching is becoming such and issue I wouldn't want to risk it.

Get your motor back in running shape as it was originally (300hp) and then go out and get a ZZ3 and beat the he** out of it.

More fun, less worry.............
 
When I bought my car it had an over the counter replacement 327/300 shortblock in it. The Original 327/300 shortblock came with the car. It is rebuildable, but I'll leave it be for the time being. Since the car is apart at the moment, I'm going the 365 route also. Intake and valve covers are here, air clearer is on it's way, but I'm having a hard time finding an affordable 2818 Holley. I've got plenty of time to shop around till I need it. Sure is nice having the NOM to play with.
 
68Roadster said:
JohnZ,
The post about the crank snout forces my question:
My 68 327/300 is drilled and tapped but I was told it does not require a balancer bolt. Whats the real deal??

6T5, glad your block is OK......
If the crank is drilled and tapped, I'd put the bolt and washers on it, just for insurance.
:beer
 
I'm assuming it is tapped for the bolt, the balancer remover screws into the crank....had it off a couple of times.

Thanks John....
 

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