Side Oilers

mrvinylman · #1 (**permalink**) 10-31-2004, 02:07 PM

How do you tell the difference between a side oiler and a center oiler by looking at it?

blykins · #2 (**permalink**) 10-31-2004, 02:14 PM

A S/O will have "humps" (they're actually oil passages) visible on the outside of the block around the freeze plug/engine mount area.

If you're good with cast numbers, you can do it that way too.

Also, I'm not for sure about C/O engines, but all S/O's had cross bolted mains.

Excaliber · #3 (**permalink**) 10-31-2004, 02:44 PM

But not all SO's had cast numbers!

Screw in feeze plugs on the side oiler. BUTT, just because it DOES have screw in freez plugs doesn't 100% mean it's a side oiler. Some SO blocks were cast that way, but never DRILLED that way and were destined to become industrial blocks.

Then you have the service blocks, cast to replace broken or worn standard issue "auto" blocks. These generally have no casting numbers.

One thing for sure, it DON'T got screw in freeze plugs and three bolts per side for cross bolted mains, it dang sure aint no side oiler.

...could be a 390 for that matter!

Michael C Henry · #4 (**permalink**) 10-31-2004, 03:21 PM

There is a buldge on the left side from the oilfilter mount rearward.That is the oil passage, hence the name" sideoiler"Oil goes to the mains first then up to lifters and heads. Some original blocks were not drilled to the lifters.

Turk · #5 (**permalink**) 10-31-2004, 03:36 PM

Don't some 427s that are NOT Side Oilers have bulges also? Just not drilled.

TURK

marcocsx3121 · #6 (**permalink**) 10-31-2004, 03:38 PM

Cross bolted mains were common to center oiler 427s as well as 406s.

Excaliber · #7 (**permalink**) 10-31-2004, 03:38 PM

10-4 Turk

A guy here in the islands has gotten his hands on a couple of such blocks and "claims" to have them drilled them successfully, he says that now makes them "side oilers". I won' t be offering to buy one any time soon!

cobrashoch · #8 (**permalink**) 10-31-2004, 09:27 PM

Slick/ Ernie - And just how do you think the factory did it anyhow? They drilled them too.
Actually, looking at it now though the rose colored glasses of hind-sight, a TO block has some advantages over a SO for roller cams. The reason for a SO in the first place was to help with the spinning rod and main bearings problem. We've came a long way since those days baby. SO blocks also had different cam/lifter towers than top oilers too. Looking over the new Genisis block they worked on that area big time too, as well as the bottom end.
cobrashock

Excaliber · #9 (**permalink**) 10-31-2004, 10:10 PM

I'm just saying I'm not interested in a block NOT drilled by the factory.

Well OK, maybe if Gessford drilled it, but thats about it!

How long a drill bit is that anyway?

bdriver · #10 (**permalink**) 11-01-2004, 04:11 AM

How 'bout this:

Quote:

As for side oiler verses center oiler, I’ll just tell you this – when I was looking for a block to use in my own rig, I did not even consider side oilers. They have thinner cylinder walls, worse core shift and worse permeability than the earlier center oiler blocks. Simply put, the early blocks are stronger. Mine is a 64 center oiler, .017” over, 428 crank, Edelbrock heads, 595 HP and has never given me any trouble. No overheating, no temper mental attitudes… side oilers are notorious for overheating because of thin walls.

marcocsx3121 · #11 (**permalink**) 11-01-2004, 05:09 AM

The center oiler that was original equipment in CSX3121 made for a strong and reliable engine. After "upgrading" (MR heads, 11.5:1 C.R., Crane .620" lift cam, blueprinting & balancing). I regularly revved it to 7000 rpm without a whimper. I never had it dynoed, but I'd guess arounnd 475 at the flywheel.

For street and occasional track use, the center oilers are fine.

Turk · #12 (**permalink**) 11-01-2004, 07:03 AM

Center Oiler, Top Oiler may have their advantages over Side Oilers. That is not the question. Poster wanted to know how to identify a Side Oiler from the rest.

Not likely that anyone selling a Side Oiler under the pretense it is a Top Oiler. One fetches more of a premium over the other. Want to guess which one?

There are blocks out there dressed to look like a Side Oiler. I have seen them. I have BOUGHT them.

Cross bolts not enough to identify a Side Oiler. Neither is the bulge.

TURK

mrvinylman · #13 (**permalink**) 11-01-2004, 05:07 PM

soooo I do have 3 cross bolts ( but i'm told all 427 have that) I do have threaded freeze out plugs ( as long as it's not from the islands) And it does have a small bulge in the block (but some 427s that are not s.o. have them) ???????????? Sounds like the presidential debate.

mr0077 · #14 (**permalink**) 11-01-2004, 06:05 PM

look for the machine plug on the front of the block, left side down by the oil filter adapter...it is the front plug for the side oiler passage.

Excaliber · #15 (**permalink**) 11-01-2004, 06:20 PM

Your getting the idea all right, not easy to identify a 427 side oiler. In some cases cannot be done FOR SURE without taking the motor apart!

I wasn't 100% for sure until I took the motor down to reduce compression and install a milder cam. Thats when I found out there are no numbers on mine, it is a late model service block. It is drilled for hydraulic lifters, something the very late model blocks had, and a good thing it is!

Behind the flywheel is cast in the block 66-427. Heck I was all excited, for SURE I have a 427 I thought. Then I found out a LOT of the blocks have 66-427 there, and it doesn't have anything to do with the year or the size!

It can be SO frustrating verifying. But NOW, I know what to look for, more than one "sign", some misleading, it takes an "expert" to be sure on SOME blocks. Those WITH numbers are "easy"!

Michael C Henry · #16 (**permalink**) 11-01-2004, 08:07 PM

There are also OEM blocks and later service and marine blocks.I have one of the later service blocks. it has webs or ridges running down the sides.

jdog · #17 (**permalink**) 11-01-2004, 08:37 PM

There is another 'sure way' to tell. Have a race, and the one that wins, will be the side oiler!

jdog
P.S. Sorry just couldn't resist!

Turk · #18 (**permalink**) 11-02-2004, 12:33 AM

I understand there is some sort of a stamping inside the threaded freeze plugs.

TURK

marcocsx3121 · #19 (**permalink**) 11-02-2004, 04:10 AM

"There is another 'sure way' to tell. Have a race, and the one that wins, will be the side oiler"

I know that the above was in jest, but I'm sure that y'all realize that the side oiler block was developed to provide longevity under prolonged high revs (NASCAR) rather than more power.

FFR428 · #20 (**permalink**) 11-04-2004, 05:03 PM

And as mentioned that all 427's and 406's were crossbolted... only a few at best of 406's were factory crossbolted. These were 63 406's that ran in NASCAR and prototype for the 427 to come. Some 406's have the crossbolt bosses but have 2 bolt maincaps others have no bosses at all. With only a year in production (62 1/2- 63 1/2) the 406 was the tweener from the 390HP to the 427 with some unique things from both. Kind of a practice block it seems. I know this is about sideoilers but I'm an advid 406 guy here. For the sideoiler you also look for the "8" shaped oil galley and oil pressure releif valve at the rear of the block lower left side. G.