anyone run 302 or 327 chevys?

[Phantom]

Lengeo - a new hybridz member I believe has one in his.

[Zerrari GTO]

A 302 is a 327 with a 283 crank. A friend has a 67 camaro with a 302 built out of a 327 block and 283 crank stock eliminator and is almost in the 10s in the quarter. From what he is telling me there is a large and small jornel cranks.

Can you guys confirm this...Grumpy are you out there? I would really prefer a 302 to anything but I realize they are rare and $$$$. If it is possible to put a 283 crank in a 327 for the same result I'll go that route.

Thanks for the help!

[Pop N Wood]

Scat sells complete 302 rotating assemblies. If you want to wind it out best to have a good forged bottem end.

 

A 302 was my dream engine for a Z. I knew a couple of guys who claimed the lack of low end was more compatible with a light weight Z with limited traction. But guys on this site convinced me that I could easily, and much more cheaply, build a 350 and trade low RPM torque for high RPM horsepower. Throw out the car craft and hot rod magazine builds designed for 3600# chevelles and put in a single plane intake, big cam and oversided heads. The end result is an engine that has the same power band as the old 302's, but with 50 to 75 more HP. Building an engine that "revs" is more a function of a stong bottem end and valve float than stroke.

[Mike kZ]

Can you guys confirm this...Grumpy are you out there? I would really prefer a 302 to anything but I realize they are rare and $$$$. If it is possible to put a 283 crank in a 327 for the same result I'll go that route.

Thanks for the help!

 

Check out this list. Compare the small journal 327 to the 302, and 283. 302 = same bore, and journal as 327 (62-67) 283 = same stroke, and journal as 302

 

Bore and stroke combos for small block chevy Engine Year Engine Size Engine Bore Engine Stroke Main Journal Rod Journal Main Caps

1975/76 262 3.671 3.10 2.45 2.10 2 Bolt

1955/56 265 3.750 3.00 2.30 2.00 2 Bolt

1979/81 267 3.50 3.48 2.45 210 2 Bolt

1957/67 283 3.875 3.00 2.30 2.00 2 Bolt

1967 302 4.001 3.00 2.30 2.00 2 Bolt

1968/69 302 4.001 3.00 2.45 2.10 4 Bolt

1976/90 305 3.736 3.48 2.45 2.10 2 Bolt

1968/73 307 3.875 3.25 2.45 2.10 2 Bolt

1962/67 327 4.001 3.25 2.30 2.00 2 Bolt

1967/69 327 4.001 3.25 2.45 2.10 2 or 4 Bolt

1967/90 350 4.001 3.48 2.45 2.10 2 or 4 Bolt

1970/72 400 4.125 3.75 2.65 2.10 4 Bolt

1973/80 400 4.125 3.75 2.65 2.10 2 Bolt

[Zerrari GTO]

Thanks Mike-looks like I'm hunt'n for 327/283 stuff!

[jt1]

Zerrari, I've got a 60 over 283, I think that's a 292, if you're interested. I'm in western NC, so we're not that far apart.

 

John

[dr_hunt]

If you use a 283 crank, cast or steel, you can put it in a 327 block, no problem. Clevite makes a special set of main bearings to put a small journal crank into a 350 block, or at least they used to, I've been trying to find them.

 

The 307 is basically a 327 crank, just the bore was smaller to make 307 cubes.

 

I went with a 350 instead of a 406, now I kind of wish I'd gone with the 302. Maybe I'll buy gears and work on getting this thing of my boys to hook up.

[Zerrari GTO]

Thanks again for the info. guys. I've already got a lead on a 327 jt1 but thanks for the offer!

[HarrisonTX]

Holy cow guys, thats alota good info. As for the price, i already have the most expensive part, the crank. Nothing else is hard to come buy, aside from pistons.

I bought the crank on ebay, for $275, not too much for a forged crank. It was still in the freaking box, never once installed. When i looked on "mortec.com" to decode the crank casting numbers, this is what i got

"3474.......283.......forged..small journal....3.00" stroke, military tank use"

I know it says 283, but a 283, and 302 is the same thing. The neat part is "military tank use" i'm just guessing it would be one hell of a crank, because if it was ment for the army, then it would have higher tolerences and stuff. It did come in a military box, and has never been installed.

The only other really expensive part is the pistons, The cheapest i have found is about $500, and yes thats forged. since all the 302's had forged pistons, i think they dont make a cast set. You guys ahve got me all excited to build this motor and stick it in.

 

If anyone reads chevy Hi-performance, theres an article in this monthes issue, they built a 355, for right at $3,000 that made 412hp. They bought holley aluminum heads, intake, and camshaft, for $1,400. i think thats a hell of a deal. The good thing about this article is it tells how much everypart cost, and the part number, so i could easly copy them, and spend the same $$.

[Guest Bic240zSS]

my dad has a 327 in his 260z and makes great power and shoots a 210 shot of nos to it all the time and works great...http://www.v8swaps.com

[pparaska]

Have a 327 - fun, winds up high. Going to a 406 - 74 more cubes means 74 more hp (actually more) for the same weight engine. If you drive on the street, the 327 can seem lazy at times down low. Just my data point.

[Zerrari GTO]

Just to follow-up. I talked to a tech at Scat about 302 rotating assemblies for a 327 or 350...it's not a cheap date. He said the crank would be semi-custom and the pistons (need dished due to 58cc heads) and rods would be $$$ in addition. When asked about putting a 283 crank in a small journal 327 he said that would work fine but the rods and pistons would probably be expensive. He strongly advised building a 327 because forged cranks, rods and pistons are still readily available off the shelf and you can "rev the snot out of them". In addition he said by adding a light weight flywheel and balancer you would still have the quick rev characteristics of a 302 when you tapped the gas.

The people at Scat were very helpful and seemed sincerely interested in providing the best solution w/the least amount of headache and expense. Thanks for the lead Pop N Wood.

[dr_hunt]

I'm not sure who you talked to but a 283 is a small journal crank just like most 327's, there is only 2 rod journal sizes, small journal and large journal in the sbc. The small journal rods are readily available off the shelf just like a 327. Pistons are available for the 302 in forged high compression only as an off the shelf item since that is what the factory version was as well. The 327 is available with a flat top since that is what truck engines had in them and some of the low HP rated 327's. Forged pistons are $$$ anyway, the difference being if you go with TRW or JE's or similar.

 

Again, it depends on how radical the engine is going to be. It's been debated and tossed around here on this forum alot. If the engine is mild, cubes and stroke will get you more HP and TQ. If the engine is radical, cubes and stroke may generate more than you can plant to the ground. So, I think that you are trying to achieve a high output small cube engine so as not to overpower the tires on the low end and pull more on the top and in higher gears. Either the 302 and 327 should accomplish that. There is something magical about the 3.25 inch stroke of the 327, I guess that is why nascar is still using it but with 4.125 bores, better breathing and 9500 rpm. I'd love to hear 9500rpm in a z.

[Psykovertible]

However, the small journal 327 rods bolt are scary as hell to me. They are only a 5/16 instead of a 3/8. Not a big difference but enough. Besides, to use the small journal crank you need the small journal block... which is more rare and antiquated by comparison to later blocks. You also run into minor stuff. old 327- filler is in intake... breather is in intake.... rods bolt are small and weaker.... block is weaker. buy the large journal 327. The additional RPM range of a 302 doesnt help much unless you are road track only.

 

just my two cents

[Heavy Z]

...old 327- filler is in intake... breather is in intake....

 

At what point did they switch? I have a 327 from a '67 vette and it is just like a regular 350 with regard to the filler and breather.

 

Another option you could explore is putting a large journal 327 cam into a 400 block using 6.2" rods. AFR did a build like this a while ago for around $3k and created an engine with 11:1 compression that ran perfectly fine on 87 octane gas. You could have your high-revving engine this way with an extra 50 cubes.

 

Here's the article, the setup isn't exactly like what you're after but it may be helpful:

 

http://www.airflowresearch.com/articles/article03/A3-P1.htm

[pparaska]

1968 is what I've always heard for the switch to the large journal on the 327. But there may have been some 67 cars/trucks with that size as well.

 

BTW, the rod bolts on the 327 (small journal) are 11/32" not 5/16". I highly recommend going to SPS, ARP, etc.

[Bilster]

At what point did they switch? I have a 327 from a '67 vette and it is just like a regular 350 with regard to the filler and breather.

 

Another option you could explore is putting a large journal 327 cam into a 400 block using 6.2" rods. AFR did a build like this a while ago for around $3k and created an engine with 11:1 compression that ran perfectly fine on 87 octane gas. You could have your high-revving engine this way with an extra 50 cubes.

 

Here's the article' date=' the setup isn't exactly like what you're after but it may be helpful:

 

http://www.airflowresearch.com/articles/article03/A3-P1.htm

 

I have built this exact motor. It is a true screamer. A couple of deviations were I went with 6.25" rods so I could use off the shelf SRP flat tops originally designed for a 400 with 6" rods. I also have the AFR's with the 2.06"/1.64" inch valve combo with AFR's CNC porting. As the article states, the sensitivity to detonation is much lower. I run 86 octane for tooling around. I do run premium when trolling for Mustangs. Mine is backed by a Tremec 5 speed, factory lightweight flywheel. It really is frightening and ripped the heck out of the stock factory Datsun rear. I'm trying to adapt a C4 Corvette third member at the moment.

[wheelman]

Bilster,

Do you have numbers on how much it cost you to build?

Part #s would be nice also.

 

In the future I'd like to build one of these and use MegaSquirt with a Holley Projection throttle body I've got. I think that would make a good combination.

 

Wheelman

[Heavy Z]

Bilster,

 

Thanks for posting and welcome, a few of us on this board have been interested in this buildup so it's nice to hear from someone that actually did it. I know you said "exact," but did you use the same cam as the article? Same 56cc heads? Same 11:1 comp?

[Bilster]

Oops...not smart to say exact and then list changes but... yes I did use the same Comp Cams camshaft, the same head part number but upgraded to the bigger valves and they received the AFR CNC port work. The heads were an eBay steal because as you probably know, they are not available from AFR anymore. I paid $750 from eBay and they needed very little to get going. If you are an eBay player put the part number 190SHST in your preferences alert. I trolled for a couple of years with that part number and was alerted to three sets in that time frame. I jumped on the first ones. 190SHST is the AFR part number. The larger valves really fill up the 58cc chambers. I would highly recommend this upgrade because the 400's 4.125" bore gives plenty of breathing room and you want to take advantage of that fact.

 

Forget the $2500 price tag Hot Rod put on this build. Even with horse trading, eBaying and discounts, I still hit the $4000 mark. The crank is a steel 327 large journal. Many people think that they are extremely rare. They are in passenger cars but not in buses. The steel forged 327 crank was used in countless school bus applications of the era. I saw on eBay that a manufacturer is selling off two 4340 steel forged lightened versions. They went unsold probably because the popularity of big cubes right now. The pistons are SRP forgies for a 400 with 6" rods. If you want to save $100, you can go with Keith Blacks or equivalent hyperuetectic. I'm going to NOS mine so I went forged. I upgraded to Max Seal rings by Total Seal. 400's are crack prone in some areas so I went with ARP main studs and head studs. Used deck plugs with holes punched out to about 1/2" for cooling. This strengthened the deck. ALWAYS...ALWAYS...ALWAYS have 400 blocks magged. The 6.25" length rods were from Dyno-flo. It's their house brand and they may be Chinese but they are good for 600 hp and they weigh an amazing 605 grams for just under $400!! I knew that even sprayed, I was going to be under 600 (150Hp NOS kit) so I feel safe. I would be glad to post pictures. Can I do that? Can't figure it out.

I am a big believer in the long rod motor. Many other members on other sites are balking at the concept. I am in the process now of building a nice standard 350 short block. The same cam, intake, heads, etc. will be bolted on and I will compare the two against each other. I can tell, by experience, there is no way in hell that a standard 350 will run on anything less than premium at 11:1. The long rod will and quite nice, thank you. No overheating or knocking. And...unless the AFR's are monster heads and they bring alot of hp's to the table. I doubt the standard 350 will match the long rods power. I mean it rips and still manages 20+ mpgs with a 4:10 gear and a T5 transmission.