Hey guys I haven't posted any engine builds in a while. I bought a 93 40 anniversary Z07 6 speed car. I had to do some work on it. But it was a pretty rare car being a Z07. They made 824 in 93. So I was going to put some AFR heads on it. But when I got it apart, I could see it was using some oil. So I changed plans and pulled the engine and decided to bore and stroke to a 396. I got CP forged pistons Scat 4340 crank and rods. And it came with a 4 bolt main block. I went with a Bullet cam 222/230 .584 lift on a 112 lsa. I also decided to use AFR 195 comp port heads. I want a mild 396, around 500hp with great street manners. I dont need another race car. I still have my 91 vette which runs 9s at 7500ft da. So the AFR 195 comp will work perfect. They basically have the same flow numbers as the 210 race ready head, doing it with a 195cc port. This will have alot of port velocity, great throttle response and torque, but flow 308 cfm so it will make some decent hp. It will have 11.55 compression which is doable with our thin air, aluminum heads, and LT1 reverse cooling also help. I reused the LT1 intake which was heavily ported. Here's some pics




Scat 4340 crank

CP forged piston and 4340 Scat rod


I degreed the cam and it was 4 degrees advanced, and it had 3 degrees ground into the cam. So I had to retard the cam timing 4 degrees. I'm using the stock timing chain set up, so I can keep the original style optispark. So I had to have a machine shop open up the cam pin hole and slot the bolt holes. So I could use an 4 degree offset bushing. That way I could change the cam timing. I need the stock upper timing chain gear, because I need the spline hole for the optispark. Most of the LT engine builds I do, I use the 94 on up later style timing cover and later opti. Then you can use a regular double roller timing chain set up, as long as you convert to an electric water pump. I also converted this to an electric water pump.


I degreed the cam after I put an offset bushing in it, and it was right on the money. I staked the bushing so it can't move or fall out.

I used small journal rods, but there is still alot of clearancing to make the 3.875 stroke clear the block. I had the cam ground on a 1.050 base circle so the rods would clear it. And the basecircle is still big enough, i can use the stock type lifter hold down set up. It's also internal balanced, and you can see 2 sticks of mallory metal in the counterweight of the crank



I used a Canton oil pan. But had to clearance the crank scraper to clear the rods


AFR 195 competition port heads


These are some of the most efficient cylinder heads AFR has ever done. It used to be to get over 300cfm, it took a port volume of 225 or 230cc's. They have a 195cc port volume and flow 308cfm @ .600 lift

I measured pushrod length and ended up a 7.200


I had to carefully trim the bottom of the gasket, then the gasket would work with the LT1 intake, and 195 comp port heads


I had my brother cut and weld the valve cover so the alternator would clear the AFR valve covers

I had to clean up the engine compartment was a dirty greasy mess. But it cleaned up pretty good

Electric water pump

I ended up putting an Accel opti on it. The old one that was originally on it died

I put a spec clutch in it

 

Welcome to the 1993 396 Z07 6 Speed Club / awesome build looking forward to your results.

 

 

Very nice. I'm right behind you, waiting on my 383 short block. If you don't mind can you share:

1. what injectors are you using?
2. any modifications needed for that clutch?
3. What/who are you using for PCM tune?

 

Im using Bosch 30 lb injectors. PCM for less did the chip, and it feels really close. When it breaks in I'll put my wideband on it. But it has to be really close. Super responsive, and runs really nice. Pulls to 6000 rpm.
I have about 50 miles on it right now

 

The clutch is a pull style clutch. So it just goes right in with no modifications

 

 

Its pretty mild, not alot of cam surge. Really good street manners. It feels like up here it would be a mid 12 car. I think at sealevel it would probably be a mid 11 car

 

Beautiful car. What headers are you using?

 

This is a tremendous build, couldn't be more envious ! Right inline cam wise with what I'm thinking for a 407 build (mild with high gears in my case, and lower compression). Any running video clips ?

 

That's awesome! Really nice work! That 396 on the bumper really makes the whole package!

When I put my LT4 back in my car it wouldn't fit with the bell housing on. I had my water pump and pulleys installed maybe that's why?

 

They are OBX headers with high flow cats

 

I have a couple video clips, but need to put them on you tube before I can put them on this thread

 

Exactly. You need to have just the crank hub on the front and leave the water pump and damper part off like mine in the picture

 

Jim, fantastic work as usual. You pluck and reinstall those engines and make it look so easy.

 

Wish a 396 or 409 could pass smog in Cali id get an LTx car in a hot second

 

Glad to see your still doing your thing,Jim! I dont think Ive ever see an accel opti before.

 

This sounds a lot like the 396 in my 96 (now owned by someone else). Mine had LT4 heads ported to very, very similar numbers to the AFR Comps, a ported LT4 intake, and a Comp Cams stick with 218/224 and .570/.565 on a 110 LSA. It had a wide power band with a midrange focus, and on a roll it would actually pull a stock C6 Z06. It would also run 55-60mph in 6th gear on the stock 3.45 gearing without chugging or bucking and get 26mpg. It's a great street engine and it was perfect for autocross use, too. It did quite well on a road course also. Enjoy your handiwork!

 

Here's a short idle video clip

 

Awesome!