The_Dane

Hey,

My English is bad... I know, and my tech knowledge on the names of all the stuff lacks as well, so please bear with me...

I have a 402 BB, cast in dec. 71, but build to 72 specs. I put it in my Firebird, to replace my 403 SB Olds, a few years back. Knew that the 402 had some issues, but money and time haven't been in my favor, but now it is so I'm starting my overhaul/rebuild to make the engine all good again.
Doing so, I have some questions I hope you guys can be of assistance answering. But first the rundown on the engine so you guys have as much info as possible

The engine was badly put together last time someone wanted to make it all good again. However they did put in some great parts along the way, but "forgot" to do it all the way through the engine. The block of the engine is good, it has Eagle Special connecting rods and a set of Speed-Pro Forged pistons. The Crank has been milled 0.20 (says so on the bearing).
It has double chaindrive and an unknown cam. The heads are as fare as i know all stock. But someone forgot to put in new oilscrapers and they used way to course sandpaper when they polished the valve-stems. So it uses some oil and this is what I want to mend.

My thought was to put a Edelbrock Preformer-Plus cam, Edelbrock Preformer intake (idle-5500) and a 650 4-barrel carb.

But here is my questions (at last

I want to put in new and bigger stainless valves in. But what size should I put in? I'm a little concerned with picking to large valves so they will hit the block where there is a little space bored into it to accommodate the valve, and hitting the pistons. I need bigger valves cause the valve-seats are scarred and now good. I'm ordering from summit-racing so if you can give a link, id be more then grateful. The shop where I'm getting the heads done, they will put in new K-Liners as well as straightening the heads if need be.

In the tops I noticed that in the exhaust-valves there is a bearing for the springs, but on the intake there is only a shim. Is this ok? Or did the idiot who messed with the engine last time, make a doo-hicky?

I might come up with more questions as the build comes alonge

Best Regards,

old dog

i would only go to the next size past what you have now ,probably 2.160 intake and 1.720 exhaust .those bearings are rotators get rid of them . use the correct vale spring and shim combination for the cam shaft,make shure the valve's will clear the piston's and you dont have to have them fly cut to clear .

The_Dane

Hey m8, and thank for the reply

The rotating bearings are stock aren't they?
I'm gonna go look for a spring-set for that cam, if one is made Else ill ask around here for the "right" combo.

The_Dane

Ok so I found out that the guy that build ny 402 was an ****. The pistons are for a 400 pontiac and to small for the cylinder. So for now the build is at a stand still.

Found a dude that has a 383 stroker, 2. Gen motor, but will my TH350 trans for the BB bolt to the 383 SB?

The_Dane

Ok, so things are progressing along nicely... or expensively... however you wanna look at it.

At this point I'm looking for some new pistons since the bore is so... yeah... I'm looking at some speed pro pistons at this point. But what size.... I'm looking at two different at this point. One is an 402P40 that fits a bore of 4,165. (my block is 4,156 atm) that will take up 5.5cc over standard. But I also found a set of L2328NF60 that fits a bore of 4,185 which are domed and will take up 36,6cc over standard pistons.

But can I go 4,185 bore? Will the block be able to take it? I very much want a higher compression to get the most out of the 99 octan pump gas we have here. (95 is the lowest) But will the extra compression hurt the driv'ablility?