whats up guys, did a deal and got a 68 nova. and this bb. and want to know is this engine any good. ok the numbers on the back of the block are 3955272, and on the front the numbers are/seem to be to41ijo, all info would be great thanks

272 in a 69 396 block,it could have possibly made it into a late 68 build car but generally its considered a 69 396 block .

As far as the jo code goes(what car and hp rating it was from factory) i dont have that info in front of me here at work,somebody else can chime in on that one.

Scott

3955272....396.......69......2 or 4 bolt

from mortec.com

JO shows up as a 1969 396/265hp 2bbl engine used on Police cars with a TH400 tranny.

oh wow thats not so great, so what ya think i should do with this thing?

keep it or sell it

its still a 396

well depending on if it a 2/4 main, i should build it up a lil?, maybe change the pistons for more compression?, does any one know if the heads are any good or decent ones?, or this whole enigne is a dud?

what are the head casting #s?

a 396 is never a dud

IMO the only BBC 'dud' is the truck 366

head # dont know were is the easiest place to get this number,

head # dont know were is the easiest place to get this number,

pull a valve cover

you'll see the casting #s & date codes cast inbetween valvesprings

If it is a 2v engine, it should have the 3933148 head....the first open chamber oval port casting. Usable compression with the standard dome piston of the era.

Mike, My first car was a 68 Nova...out with the 307 and in with the 427 and a ton of go-fast parts. Too bad you are X-country so I can't talk you out of the car

Boat Anchor :D:D I have 2 502 if you want to do a big buildup

ok so open champer is that good or bad, so how much compression does this motor have?, and thats cool, yea im into it also, i like it and its not that bad just need the driver quarter and pass lower side quarter patches, and the just the front floor boards, its originally 307 also, but it has a "corvette 327" the guy said. i stated her up yesterday and it sounds camed up. ima get the numbers off of that later today, along with the head#s and ima see if i have enough time to pull the oil pan off the 396.

open vs closed is personal preference

I like open chamber 'cause they flow better

others like closed since its easier to build compression.

sell the block.
get some dough for it then buy into more displacement if power is a big issue. this block build is gonna cost ya anyways.
if power is not a big issue, along with its originality then keep and build. The block is certainly not a slouch compared to most.
just my 2cents.

ok so if there open, it flow better and thats what these motors need good flowin heads rite?, and for compression, you chose the pistons for the compression u want? rite, and for power it would be fine around 500 550 at motor, and yea i would like to keep originality.

ok so if there open, it flow better and thats what these motors need good flowin heads rite?, and for compression, you chose the pistons for the compression u want? rite, and for power it would be fine around 500 550 at motor, and yea i would like to keep originality.

correct, buuuuut 500-550hp from a 396 is doable but it takes some work

& hell 400hp is easy & still makes for a real good street engine

yea but i already got the 71 396/402 thats going in the 68 malibu and with the cam and shims i got for it ,i should theoritically be about the 400 mark. from what you guys tell me, i dont want the same thing, what u guys think

well it will have diff gears so it should perform a lil different

all I'm saying is, 500-550 can be done but now your talking higher comp. & big roller cam with head work.

so for higher comp swap out the pistons, and head work what kind of head work?

OK Mike, a ton of questions here!!!!!

Again, consult any book on the Big Block Chevy...
How about a new line for each question...easier to follow. Thanks in advance!

IF you do have the 148 heads on this NOVA 396, their 112cc chamber and the stock domed 325/350 10.25:1 pop-ups (figured with 100cc heads)...give you a 9:1 CR....for a nice street cruiser or occasional track engine. See, Chevy put the larger chamber 148 heads onto their regular shortblocks to make lower compression for regular fuel usage.

My bud Terry Reed had a set of seriously worked-over 148 heads on his 69 Nova drag car. They were ported, big valves added, etc....engine dyno'd over 600 horse when done, naturally a HUGE roller cam and 13:1 pistons.....427 Cubic inches.

If this "JO" engine does pan out....it is as good as any of the other 396s out there strength wise....except for the 396/375 Hi-Perf engines. Performance-wise, the oval port engines will make far better street engines.

ok im back the heads on the jo motor are 3904390, didnt get a chance to take the pan off yet, so what kind of heads im i workin with.

ok also ya may help finding what engine is this, this is the motor thats in the nova pad number vo20itbx/ v02oItbx.

and last but not least i never found out what heads were on my 71 396/402 and these are the numbers 3993820. thanks guys

3904390....67......oval..CLOSED..396, 427, 98cc chamber

3993820....71......oval...OPEN...402, 113cc chamber, 255/114 ports

again, from mortec.com

ok so now knowing that were does this jo stand, how can we get it to make a 400+ at wheels

also for the 71 with the 238/248 cam, are those heads(3820) good match.

OK Mike,

Someone put the early 390 heads on the JO engine to give it more compression.
So now you have a 10.25: CR engine. Basic repairs (if needed), cam and valvesprings.

Yes, that cam will work great on you 71/402 or your new "JO" engine

yea george thats the cam thats going in the 71 that you reconmended with the valve springs you also stated i should get, im still waiting for them to come in the mail

now having said that, it has 10.25 cr how much power should it have now

so how much cr does my 71 have, im i going to have twin motors

Mike,

The engines are pretty close...
The 71 with domed slugs (.300" forged if I remember correctly) and open chamber heads
the 1969 "JO" engine with smaller domes and closed chamber heads
The compression ratios will be nearly equa in the 10-10.25:1 range.

The 71 open chamber engine SHOULD make more power 10-30 hp over the "JO" closed chamber engine if everything was the same. With good assembly practices and a competition valve job.....right at 400 horses at 6500 rpm

so after all not that bad of a motor, thanks george once again saved the day, always keep my hopes up,
know what would consiest of good assembly practices, any lil tricks i should know

Don't thank me Mike....Dangerous Dan and others have been there for ya too!

Tricks you should know:
Lots of places to find tricks and knowledge:
1. Get the HOW TO HOTROD MY BBC book by Fisher and read it 10 or 15 times
2. Get BIG BLOCK CHEVY PERFORMANCE by Dave Emanuel
3. Get the 15 or so boxes of car mags (mostly Chevy High Performance and Super Chevy) out of my garage and read them all....there will be a test afterward
4. Apprentice yourself to one of the 'names' of drag racing when in your teens

OK, now to summarize all this info....hmmmmm
The difference between an engine that is OK and one that impresses your friends is the combination of parts that work well together. This includes the engine parts, transmision, and gearing, etc. This is what we've been working over the last few weeks. After that, careful preparation. Have the best shop in town do a competition valve job on your heads. Easy 25-35 horse gain over a production valve job. Have your heads pocket-ported if you have the funds. See some of the sources above about relieving the top of the cylinder for flow. Pay attention to your cylinder hone, ring composition, and ring end gaps.

other tips before you build
o ensuring all your clearances have been checked and re-checked prior to the actual build
o attention to detail in the cleanliness of components prior to and during assembly,
o ensure you use the right sealant or lubricant on your bolts as appropriate
(create a list and get all the items before the assembly date)
o use the correct torque values and correct torque sequence
o degree in your cam
o do NOT use the rubber intake manifold gaskets for the front and back of your engine's valley....use a bead of silicone
o follow the cam break-in tips and oils to use tips in the ENGINE forum.

do u think ill have any clearence issues on my 71 because of that cam?

i got the cork gasket for the front and rear valley

thanks for info and help guys

no clearance issues..

throw away those cork end gaskets & use a bead of silicone like George said.
use about a 1/8 in. bead across the the front & rear.

cool yea i used the cork and put some blue silicin, but i have to remove all of that anyways to put the cam back it, u think the intake gaskets i still could use?

no don't re-use intake gaskets.....its a bad place for a leak.
not worth saving $20 for.

Mike,
No issues with the Summit cam for piston to valve or retainer to seal clearance.
This is why I recommended this cam to you....too easy!
Much above .540" then you should check....

Lay the silicone sealant bead on the ends of the lifter valley ....let the beads sit a few minutes to start curing then drop the intake on. Caution here is that you have enough goo down to get a good seal but not so much goo that will come off the edge and into your engine!

thanks guys, im sure ill be back to ask more question, oh and my cam already arrived, know awaiting springs, oh and my disc brakes are here yay:hurray::D, no instructions dam.

ok i thought and thought, and yea i wanna build this 69 396,
power:between 500-600
use:street and strip
how much hp can this crank hold?
should i use the stock crank?
pistons and rods have to go,
what rods and pistons should i get?
what bore should it be?

started to take the motor apart, got the torker 2 2.0 intake off!,
and saw black rods, 7131/7141 comp. cams magnum,is that stock specs
pistons and rods no hard carbon build up everything looks fresh,
pistons if not the same dome bigger then the dome on my 71 396?
springs in the head not double springs but has something that looks a lil like a another spring?is that stock,
any thoughts guys

ok i thought and thought, and yea i wanna build this 69 396,
power:between 500-600
use:street and strip
how much hp can this crank hold?
should i use the stock crank?
pistons and rods have to go,
what rods and pistons should i get?
what bore should it be?

Stock 396 crank, cast or steel, will take whatever you throw at it. NO2 too!

Use a set of aftermarket rods or just find a set of thumb rods and have them upgraded with ARP's, they'll handle pretty much any thing you can throw at them too.

The L2242F forged 11-1 pistons are tough but heavy. I'd use them with a set of 781-049 lightly ported heads to keep the compression civil but also gives you the option to run close to 12-1 with a set of closed chamber 96-100CC heads. You can choose a lighter aftermarket piston but those TRW's are nearly bullet proof.

To get the HP numbers you want, you'll likely need the higher of the two compression options and need a hefty solid roller and spin it up to and maybe about 7000 RPM's, which it will take easily. One of UHarolds recommended solid flat tappets may get you to 500 HP range.

I may be off base as I've never flow tested or dyno's any closed chamber heads but I would, and do, like to leave the stock valve size in the closed chamber heads. This is because a nice port job creates a very efficient fuel/air charge and the velocity is better.

If a person puts in larger valves, they are not as unshrouded as the smaller valves, and may actually lose flow unless the larger valves are unshrouded. If you go larger valves and unshroud the chambers, you lose CC's and lowers your compression. Kind of a double edged sword.

Now a larger cubic inch motor may want the larger valve option but a 396 should do the job with a 2.06-1.72 valve combo.

On that note, this is my thinking here and I may be off base but I've made great power following this thinking. When building a similiar cubic inch small block 400, one can make 500 plus horsepower with 2.02-2.05/ 1.60 valve combo's. Why wouldn't a 396 make the power with a 2.06-1.72.

Mike,
You probably want to sell that Torker II or hang it on the wall as a piece of ART.
The only real use for that intake is to fit a BBC under the stock Vette hood.
I run an RPM on my Vette with a domed L-88 hood.
The RPM will make 25 more ponies than that Torker II if I have my facts straight.

what are the head casting #s?

a 396 is never a dud

IMO the only BBC 'dud' is the truck 366
Yeah and the crank in IT is special 6233 steel for a 396 427

Use a set of aftermarket rods or just find a set of thumb rods and have them upgraded with ARP's, they'll handle pretty much any thing you can throw at them too.

The L2242F forged 11-1 pistons are tough but heavy. I'd use them with a set of 781-049 lightly ported heads to keep the compression civil but also gives you the option to run close to 12-1 with a set of closed chamber 96-100CC heads. You can choose a lighter aftermarket piston but those TRW's are nearly bullet proof.

To get the HP numbers you want, you'll likely need the higher of the two compression options and need a hefty solid roller and spin it up to and maybe about 7000 RPM's, which it will take easily. One of UHarolds recommended solid flat tappets may get you to 500 HP range.

I may be off base as I've never flow tested or dyno's any closed chamber heads but I would, and do, like to leave the stock valve size in the closed chamber heads. This is because a nice port job creates a very efficient fuel/air charge and the velocity is better.

If a person puts in larger valves, they are not as unshrouded as the smaller valves, and may actually lose flow unless the larger valves are unshrouded. If you go larger valves and unshroud the chambers, you lose CC's and lowers your compression. Kind of a double edged sword.

Now a larger cubic inch motor may want the larger valve option but a 396 should do the job with a 2.06-1.72 valve combo.

On that note, this is my thinking here and I may be off base but I've made great power following this thinking. When building a similiar cubic inch small block 400, one can make 500 plus horsepower with 2.02-2.05/ 1.60 valve combo's. Why wouldn't a 396 make the power with a 2.06-1.72.

ok yea with the rods ill feel more confident with aftermarket rods like eagle rods, what are the lengh of rods i need 6.???

so thats what i shoud be looking for 11.1 pistons? if the price aint much diff i rather go with lighter, they say less rotating mass =more power, or will it cause balancing issues?
and for the heads the ones i got are 98.4cc closed,so most likey thats the way im going, quess im gonna have a good amount of compression,

for the cam wich i less maintness required?, and price friendly,what would work better for this type of combo.

ok so what your saying is that all i should do is the machine work, port/polish, 4angle valve ect ect. and not bigger valves, it wont give me any power gain, due to it less compression,

and at the end i will be able to use normal pump gas, premium

thanks guys i think im getting there

Mike,
You probably want to sell that Torker II or hang it on the wall as a piece of ART.
The only real use for that intake is to fit a BBC under the stock Vette hood.
I run an RPM on my Vette with a domed L-88 hood.
The RPM will make 25 more ponies than that Torker II if I have my facts straight.

not all that good then, thought i had got something good for once, hell of a junk pill at the end.

whats the power bands on the rpm manifold. i think i need a single plane, or do i need a dual?

ok yea with the rods ill feel more confident with aftermarket rods like eagle rods, what are the lengh of rods i need 6.???

GHK: Standard rod length is 6.135" which works wel with the short stroke 396/402 engines. There are longer rods but a luxury. These would require specialty pistons, $$$

so thats what i shoud be looking for 11.1 pistons? if the price aint much diff i rather go with lighter, they say less rotating mass =more power, or will it cause balancing issues?
and for the heads the ones i got are 98.4cc closed,so most likey thats the way im going, quess im gonna have a good amount of compression,

GHK: Darryl mentioned these as they are common and affordable. And as the 69 engine will be serious power, might as well run high compression. Less piston wt allows safer rpm at higher speeds. If your engine makes power at higher speeds then more rpm is good hence more power. Trust me, lt wt pistons do cost more $$$ so you have to figure out your own comfort level.

for the cam wich i less maintness required?, and price friendly,what would work better for this type of combo.

GHK: Race only, solid roller. A bit more maintenance with doing the valve lash a few times a year. Benefit is some more power.

ok so what your saying is that all i should do is the machine work, port/polish, 4angle valve ect ect. and not bigger valves, it wont give me any power gain, due to it less compression,

GHK: If you insist on putting bigger valves in the heads you must have the chambers clearanced so the valves are not shrouded, ie, right up against the chamber wall. So, opening up the ports reduces compression a little. Darryl is saying stock valve sizes are OK for a 396/402, no un-shrouding required. Money you save by not having larger valves installed, etc is money for pocket porting or better than stock valves. If you are going to buzz the engine up...which I think you are...you should definitely consider some performance valves.

and at the end i will be able to use normal pump gas, premium

GHK: This is a question that will depend on the cam you choose. Really high compression will require really big cam to run pump gas.

thanks guys i think im getting there

whats the power bands on the rpm manifold. i think i need a single plane, or do i need a dual?

GHK: Torker II power is 2500-6500
RPM and RPM Air Gap is 1500-6500
Your 60' times will be far better with the RPM or RPM A-G.