4 Bolt Main Conversion

**Fakepower** · 09-30-2010, 09:53 PM

Hey guys, I was talking to Matt from DR today and i realized I needed some more information.

I am putting a 4 bolt main built engine (pics will follow in a few weeks) into my 91 RT TT. What are the differences in parts/procedures that I need to be aware of? thanks

Edit: To answer my own question I did some digging and found these sites:
http://www.stealth316.com/2-2bolto4bolt.htm

http://www.wrenchmonkey.com/Webpages/4bolt.html

However if you have any more information you'd like to add feel free!

**akotten** · 10-01-2010, 12:17 AM

Something I should consider during this next rebuild...In for more info from people that have actually done this.

**Fakepower** · 10-01-2010, 08:58 PM

well to be honest the only reason to do this is if you get a block cheap. Throw a new forged crank in the 2 bolt. I think IPO has made around 800hp on a 2bolt main using the ARP 2 bolt main kit from 3sx.

**1stStealthN/A** · 10-03-2010, 08:45 PM

I did the John Monin 4 bolt swap but it's overkill for me. Two bolt with a forged crank would have been fine.

**GTOJOE** · 10-03-2010, 09:21 PM

what is required if I drop a 4 bolt engine in my 1st gen that currently has a 2 bolt. Alternatively what is required fi I drop the complete 2nd gen setup in my car? I kow what is needed for drive train etc so just engine wise is there anything required? As far as I know th only difference is the CAS????

**Ninja Performance** · 10-03-2010, 10:18 PM

All you need for a 2 bolt to 4 bolt is

4 bolt block
4 bolt oil pan
4 bolt oil pump
4 bolt Alt/AC to oil pump bracket
4 bolt Timing cog OR re mark a 2 bolt, the timing mark on a 4 bolt oil pump is moved versus the mark on a 2 bolt pump

Of course, you could make over 700AWTQ and 800AWHP on a 2 bolt, so unless you are trying to make HUGE power, don't worry about it.

-Chris

**Chris@Rvengeperformance** · 10-04-2010, 04:15 PM

Originally Posted by Import Power

All you need for a 2 bolt to 4 bolt is

4 bolt block
4 bolt oil pan
4 bolt oil pump
4 bolt Alt/AC to oil pump bracket
4 bolt Timing cog OR re mark a 2 bolt, the timing mark on a 4 bolt oil pump is moved versus the mark on a 2 bolt pump

Of course, you could make over 700AWTQ and 800AWHP on a 2 bolt, so unless you are trying to make HUGE power, don't worry about it.

-Chris

aren't the transmission stays and oil returns slightly different?

**green-lantern** · 10-04-2010, 07:34 PM

Originally Posted by Import Power

All you need for a 2 bolt to 4 bolt is

4 bolt block
4 bolt oil pan
4 bolt oil pump
4 bolt Alt/AC to oil pump bracket
4 bolt Timing cog OR re mark a 2 bolt, the timing mark on a 4 bolt oil pump is moved versus the mark on a 2 bolt pump

Of course, you could make over 700AWTQ and 800AWHP on a 2 bolt, so unless you are trying to make HUGE power, don't worry about it.

-Chris

Oh crap! I didn't do this. Is a 95 two blot NA cog different also? I was wondering why my marks didn't match up. I was thinking the heads might have been decked too many times or something. When all of the heads where lined up then the cog was off a little bit but not a full tooth.

Edit: I also used the bracket off my NA. I had posted a thread about it but didn't get any responses. I did make it work but I had to do some shimming or something like that to get it to work.