327 small journal crank

[66fleetsidewarrior]

I've got a 327 out of my '66 c10. Rebuilding the motor into something mean. Measured the journal and the rod size was 2 inches and the main was 2.3 inches which comes out to the small journal crank dimensions. I am wondering what the rpm range is with this setup is. Looking at some rebuild kits for a .030 over and was wondering if the kits were partial to a small or large journal crank. Right now I am just looking on summit but if it is not specific enough I will look elsewhere if needed. Any input is appreciated.

Also, If anyone has used a summit racing brand cam I was curious how they held up and if they are worth buying. thanks.

[Captainfab]

If you are looking for a complete rebuild kit, it will have to be specifically for a small journal ('62-'67) 327. Of course you can also just purchase the necessary parts individually. The only things that are specific to the sj will of course be the bearings, front and rear seal, and rod bolts. There are a few other odds and ends, but mostly if you are looking to do a original restoration.

The rpm range for any engine whether small journal, medium journal or large journal, is going to be dependant on how the engine is built.

As for the durability of the Summit brand cams, they should not be any less durable than any other flat tappet cam. The main concern with any flat tappet cam is that strict attention is paid to the breakin of the cam, as well as running an oil that has sufficient ZDDP for a flat tappet cam to survive. Keep in mind that the Summit brand of cams are all old school designs, and that there are better cams out there.

[chevyrestoguy]

There's absolutely nothing wrong with having a small journal vs. a large journal 327. Actually, the large journal 327s were only around for the last 2 years of the 327 production run, and only because Chevy went to the large journal on all of the small blocks in '68.

As far as the rpm range of a 327, the sky is the limit. A properly built 327 will buzz to 7000 rpm or higher quite easily. As far as an engine with both torque and horsepower capability, the 327 is a great engine. Probably my favorite SBC ever.

Summit cams are cheap, but like John says, there are much better cams on the market. Cam technology has come a long way in the last 10 years now that they're using computers to design cam profiles. Save your money and go with a newer technology cam from a reputable company. To me, spending $75 more on a cam that makes more horsepower and torque is worth every penny.

Like it was mentioned, you have to be very diligent when breaking in a flat tappet cam with today's oils. The lack of zinc in today's oils will kill a cam quickly during the initial break-in. You must use a proper break-in additive, along with an oil that provides you with the most amount of zinc possible.

[tincan1966]

The RPM limit of an engine is determined by the parts in it.

trying to achieve 7000+ rpm with stock rods and pistons is probably not a good idea. Also, the stock valvetrain will not sustain that type of use.

Sounds like you're trying to build on the cheap side, but yet have a high rpm, high horsepower engine. Those don't happen together.
What are you wanting to do with the engine? And how high rpm are you wanting? For a street-driven truck, how much rpm do you really need?

[66Submarine]

I'll toss in that the "old school" cam designs are probably a good choice for a DD IMHO. The "new" cams use much more aggressive profiles and heavy valve springs to make more power, but that also means more stress/wear on the cam and valvetrain. Some are worse than others in this regard; you might do a google search for whatever cam you are planning on running to see if other people are having issues with them.

[66fleetsidewarrior]

Originally Posted by chevyrestoguy

There's absolutely nothing wrong with having a small journal vs. a large journal 327. Actually, the large journal 327s were only around for the last 2 years of the 327 production run, and only because Chevy went to the large journal on all of the small blocks in '68.

As far as the rpm range of a 327, the sky is the limit. A properly built 327 will buzz to 7000 rpm or higher quite easily. As far as an engine with both torque and horsepower capability, the 327 is a great engine. Probably my favorite SBC ever.

Summit cams are cheap, but like John says, there are much better cams on the market. Cam technology has come a long way in the last 10 years now that they're using computers to design cam profiles. Save your money and go with a newer technology cam from a reputable company. To me, spending $75 more on a cam that makes more horsepower and torque is worth every penny.

Like it was mentioned, you have to be very diligent when breaking in a flat tappet cam with today's oils. The lack of zinc in today's oils will kill a cam quickly during the initial break-in. You must use a proper break-in additive, along with an oil that provides you with the most amount of zinc possible.

This is the kit I am looking at for a rebuild. I have not been able to find any information about the rod size/small journal, large journal. Any thoughts on the kit?

[66fleetsidewarrior]

Originally Posted by tincan1966

The RPM limit of an engine is determined by the parts in it.

trying to achieve 7000+ rpm with stock rods and pistons is probably not a good idea. Also, the stock valvetrain will not sustain that type of use.

Sounds like you're trying to build on the cheap side, but yet have a high rpm, high horsepower engine. Those don't happen together.
What are you wanting to do with the engine? And how high rpm are you wanting? For a street-driven truck, how much rpm do you really need?

I'm not looking for anything crazy. The cam I am putting in is a comp cam with about 505 lift and 247 duration at 050. Little bit bigger heads than what was stock to support the cam.

[66Submarine]

I guess you are talking about something like their XE284? That's a pretty lumpy cam for a 327 lol. I guess this is not a "driver" truck?

[66Submarine]

FYI, here's a 284 comp in a 350:

72 nova 350 build - YouTube

It'll be even more ragged in a 327.

[awbrown]

I would have to know what you have for compression , rear gear ratio, and if you have headers , trans type,but I will tell you it is easy to over cam a small cubic inch engine , 247@.050 is way to big , unless you run 4:11 rear gear , nomally 222@.050 .447 lift is a great daily driver cam ,easy on parts and cheap .. failure to match a cam to the vehicle or go too big is just the kiss of death for bottom end torque..... Not to mention the low vacuum and idle quality ..

[Captainfab]

I don't see anything about what kit you are referring to. I definitely agree with the others, that is way to much cam for a street driven 327 for the average guy.

Originally Posted by 66fleetsidewarrior

This is the kit I am looking at for a rebuild. I have not been able to find any information about the rod size/small journal, large journal. Any thoughts on the kit?

Originally Posted by 66fleetsidewarrior

I'm not looking for anything crazy. The cam I am putting in is a comp cam with about 505 lift and 247 duration at 050. Little bit bigger heads than what was stock to support the cam.

[Rich 5150 69]

If he were to step into a retrofit hyd roller from comp cams would be a better choice all around although more money up front he would get just a little more HP from a roller vs a standard cam, something like a 270 HR. he`ll need to build in a 9.5 compression with a set of fuelies on the deck would work well for him, mild gearing...we just need a little more info....