3400 top end swap questions

[niik000]

Ok so i read black34v6's sticky thread about the 3.4 and using the 3400 parts, but i still have a few questions.

on FWD motors, the intake faces the tranny, and the airbox is usually above the tranny, and the back faces the accessories. so if i bolted this onto my car, why wouldnt it be backwards?

and if i did this, i would be removing the upper and lower intake, and the heads, so i might as well upgrade the cam right?

And if i just did the top end swap i would have a crazy high compression ratio unless i put in other pistons. Would i have to pull the motor to do that?

[nightrider2]

Re: 3400 top end swap questions

you have PM

[Forced_Firebird]

Re: 3400 top end swap questions

Ok so i read black34v6's sticky thread about the 3.4 and using the 3400 parts, but i still have a few questions.

on FWD motors, the intake faces the tranny, and the airbox is usually above the tranny, and the back faces the accessories. so if i bolted this onto my car, why wouldnt it be backwards?

and if i did this, i would be removing the upper and lower intake, and the heads, so i might as well upgrade the cam right?

And if i just did the top end swap i would have a crazy high compression ratio unless i put in other pistons. Would i have to pull the motor to do that?

You can change the pistons in the car, but it's a pain. A 3500 top end will give you 11.5:1 SCR with the stock 3.4 pistons(not crazy with aluminum heads and backing off timing). The 3500 UIM doesn't fit in a 4th gen fbody without modification, but the 3400 UIM bolts to the 3500 LIM.

Both manifolds on the 60*'s can be moved 180* so the t-stat housing faces front, just like the heads can be used on either side.

Cam is a good idea. A 262 grind will jive with your ECM (kind-of) and work well - especially if you use the 3400 pistons.

[niik000]

Re: 3400 top end swap questions

So if I used a 3400 uim and a 3500 lim I wouldn't have to worry about the pistons? But what heads do I use?

[nightrider2]

Re: 3400 top end swap questions

10.5:1 is still even high for pump gas. 11.5:1 is 105+ octane. just swap the pistons 9.6:1 is better than stock and you won't have issues with detonation.

[niik000]

Re: 3400 top end swap questions

Cool thanks. And I'm going to need bigger fuel injectors and fuel rails right? What about the pump? And can't I just order some thick fuel lines from summet or whatever insted of the rails?

[niik000]

Re: 3400 top end swap questions

And do I do the rods too or just the pistons?

[nightrider2]

Re: 3400 top end swap questions

keep the rods if theres no sign of obvious damage. the pistons will fit them. It would be highly advised to have an experienced engine guy put the bottom end together, less chances of kaboom

[niik000]

Re: 3400 top end swap questions

thats what i was thinking, or at least have one guide me through it. i know a few.

[Forced_Firebird]

Re: 3400 top end swap questions

10.5:1 is still even high for pump gas. 11.5:1 is 105+ octane. just swap the pistons 9.6:1 is better than stock and you won't have issues with detonation.

You have to remember these aluminum heads resist detonation far superior to the iron counterparts. 12.6:1 has been done on 87 pump gas and a good tune - stock ECM timing for the iron heads is advanced way too far even for 9.6:1. Aluminum heads don't like the advance as much as the iron heads do, they actually will make more power if you back off the advance (but that's hard to do with the OBD1.5 ECM and DIS ignition).

My car is going to be almost 12:1.

[nightrider2]

Re: 3400 top end swap questions

It doesn't matter what material the heads are...the fact is unless he runs MS theres no way it would run. I also spoke with the lead guy from Fast chip and from what I'm to understand, the 94 3.4 doesn't have much advance at all. Now because I'm a freaking genius I figured out how to manually adjust the timing on the DIS 3.4, and its my secret!!!!!

[Forced_Firebird]

Re: 3400 top end swap questions

It doesn't matter what material the heads are...the fact is unless he runs MS theres no way it would run. I also spoke with the lead guy from Fast chip and from what I'm to understand, the 94 3.4 doesn't have much advance at all. Now because I'm a freaking genius I figured out how to manually adjust the timing on the DIS 3.4, and its my secret!!!!!

Keep it ;)

You can only adjust base timing. The real crank trigger is in the block, and you can't change that without moving the pickup in relation to the reluctor wheel that tells the ECM when #1 is at TDC.

[niik000]

Re: 3400 top end swap questions

im aittle lost i think, so is Froced firebird saying i can run 87 gass with the top end swap and my pistons if i retard the timeing, and nightrider2 says he is wrong? i would love to not have to mess with the bottom end. (whats MS?)

[Forced_Firebird]

Re: 3400 top end swap questions

im aittle lost i think, so is Froced firebird saying i can run 87 gass with the top end swap and my pistons if i retard the timeing, and nightrider2 says he is wrong? i would love to not have to mess with the bottom end. (whats MS?)

Like I said, you can do it with a tune. You have OBD1.5 that isn't popular in the tuning world. MS is MegaSquirt.

If you want to keep the stock ECM and tune, then changing pistons is your best option. (So both nightrider2 and I are correct).

[niik000]

Re: 3400 top end swap questions

cool. putting in a computer sounds eazer than swaping pistons, but probably alot more expencive right? but i would like to be able to retard the timeing bacause if i did the swap the next thing i would do to the motor would probably be spray. but that wouldnt be for a long time. for an ecm and tune im looking in the $500+ range right?