306 H/C/I with spray, am I gonna kill my block?

[KingofBattle119]

Long story short, I've got a 5.0 coming out of a totalled fox, has TFS Streetburner H/C/I, made 309whp and 337wtq. It's going into my new 93 LX vert. While the engine is out, my shop has to clean it up anyways and take the thing apart, so I was thinking of getting it bored over to 306 and putting Trick Flow flat top pistons in. Maybe up compression a little. After that, the only power mod I've been considering is a Zex wet kit, small, prolly 75 or 50 shot.

The car is gonna be mostly a weekend cruiser, driven 2 or 3 days a week. It'll probably see a handful of passes at the 1/4 or 1/8 mile once or twice a month in the summer and fall. Am I wasting my time on a stock block that is just going to explode, or should it be fine for the power/use I'm looking for?

 

[FastDriver]

Tune it right, and it will be fine. The guy that bought my old combination made 307 rwhp/330rwtq with it n/a (a little less than I did). Then he added a zex 125 shot and made 450rwhp and 500 ft-lbs and drove it for about a year before he sold it. I don't know what happened to it afterwards.

Chris

 

[281pony]

that will make sub-400 rwhp, your fine with a stock block. just get a good tune, that is your best friend.

 

[90lxcoupe]

youll be fine if it runs right, a friend of mine has been beating the bag outta his 302 with a 175 kit for about 2 summers now and its holding up just fine

 

[KingofBattle119]

Okay great, thanks a lot guys. I was already feeling pretty good about this, was just looking for some second opinions.

 

[281pony]

Okay great, thanks a lot guys. I was already feeling pretty good about this, was just looking for some second opinions.

just make sure you get a good tune. people run alot more power then your aiming for, with no issues, but it's all in the tune.

 

[90lxcoupe]

just make sure you get a good tune. people run alot more power then your aiming for, with no issues, but it's all in the tune.

Dont really need a "tune" Just back the timing off a few degrees. From what i remember he didnt change anything with a 75 shot and retarded the timing 4 or 6 degrees with the 175 kit.

 

[FastDriver]

Definitely not the right way to do things, 90. retarding the timing doesn't correct a deficient AFR. Adding nitrous certainly has the potential to lean things out in a big way.

 

[90lxcoupe]

Definitely not the right way to do things, 90. retarding the timing doesn't correct a deficient AFR. Adding nitrous certainly has the potential to lean things out in a big way.

Should have specified, he is not using a dry kit, it uses a fitting on the stock line to a fuel solenoid that is part of the nitrous kit. Car has never seen a dyno, made a good ammount of passes and had a lot of nitrous run thru it on the street. Runs good, idles better than my car did with a tune in it. haha

 

[FastDriver]

Can the fuel solenoid be adjusted to lean or richen the mixture?

 

[90lxcoupe]

Can the fuel solenoid be adjusted to lean or richen the mixture?

sure can! Thats why theres a fuel jet for each nitrous jet.

To the OP, i think your wasting your money on doing a 306 on a stock block, just hammer the stock bottom end till somthing breaks. Removing .030'' of material from each hole on the block is only going to further weaken the block IMO, and you wont make that much more power with 4 cubic inches difference.

The stock 302 pistons have alot of meat on them and thats why i think that a tune isnt needed for the juice. My buddies car gets its ass handed to it every time its sprayed and just asks for more. Just stay consistent on the bottle pressure and read the plugs. A plug reading is going to tell you alot more than a number on a wideband that is reading an accumulation of exhaust favoring one side of the motor. Also, dont turn the nitrous on too early, put a window switch on it activating it at whatever the motor peaks at naturally aspirated and use a WOT switch to activated the window switch.

 

[FastDriver]

90, does the fuel solenoid automatically accomodate lower bottle pressure, or will it cause an overly rich condition?