Stock bottom ends can handle plenty with these engines, as long as you're not detonating

 

Ok, I want to see a top swap maxing out a blower and also on the stock tranny. Sounds like a great idea to me.

L67 swap is the same price as a top swap and a hell of a lot easier. I havent done one though so I guess I don't know what I'm talking about.

Also especially if he is doing an engine swap anyway. Why the hell would you swap in an l36 and stock tranny only to tear it apart and top swap it??

 

I didn't say **** bout the tranny being stock, you need an upgraded tranny when you get to mid 13's

Bottom end, guys have ran 11's on stock bottom ends AFAIK

And really, a stock 4t65e-hd is just as weak as a stock 4t65e, the only difference is the differential/gearing, which really don't make a **** anyway as far as reliability goes

 

Okay, here’s the deal with your thoughts MONTE99SS. Pros and cons for either a top swap or an engine swap.
Top swap
Pros:
Good bang for the buck
More hp due to higher compression (9.4:1 vs 8.5:1). Plus you could go with even higher compression with a set of Cometic head gaskets
Best route to go for a big hp M90 setup. Almost no M90 powered 3800 is making over 350whp
Cons:
L67 swap is easier (pull engine out, put new engine in)
Easier to mess up (just ask Enzo)
In MONTE99SS’ case, he would have to pull out the L36 from the Grand Prix, build it first, then install it. Or install the top swap after the engine swap has happened. LOTS of work
L67 swap
Pros:
THOUSANDS of GM cars came with this engine and even more people/resources will be available for you
More reliable then a top swap due to the fact that you’re not taking major components off of the engine (like the heads with a top swap)
Best route to go if you only want a mild increase in hp (anything less than 300whp or so)
Cons:
Doesn’t make as much hp, and by quite a bit actually
In MONTE99SS’ situation you still need to swap the tranny (which would also be a con for an L36 swap with a top swap)
Is it really worth doing if you’re only going to keep the engine close to stock? I mean, spend just a little bit more and you can get a stock L67 powered car. The L67 cars are plentiful and fairly cheap nowadays (many are under $5k)


The next thing that I would like to cover is what you’re planning on getting from the Grand Prix MONTE99SS. You can use the engine and tranny from the Grand Prix, but the cradle and wiring harness will be useless to you. The cradle from the Grand Prix only works in 2<SUP>nd</SUP> gen w-bodies whereas your Monte Carlo is a 1.5 gen w-body. In order to do a 3800 swap on a 3100 powered 1996-1999 Monte Carlo you will need to have a wiring harness from a 1998 or 1999 Monte Carlo Z34 or Lumina LTZ. I’m not sure if the PCM would work from the Grand Prix either, but if you’re planning on doing a top swap or engine swap, then I would just save up for a retuned PCM from ZZP.
IMO, if you’re looking to have a 3800 powered 5<SUP>th</SUP> gen Monte, then I would just buy a 1998 or 1999 Monte Z34. They’re going for about $4k or less (with many in the $2k price range). It might be hard to find, but in the end you will save a lot of work, and have a pretty good platform to start from.

 

Sticky ^^ lol

 

Just a couple of corrections...

Actually the Series-II L67 has an 8.5:1 Ratio... the different between the L36 & L67 compression is really quite small

Stock-to-stock, the L36 top swapped only makes 7 more HP ( 240 vs 247, 3% increase ) than the L67 due to compression. It may make some more power due to the fact that you have to 'tune' the L36 though

BBEngineer

 

bbengineer, thank you for the compression correction. I don't know why I did that, but I have edited the post in order to be accurate.

Your second correction though needs more explaining if you could. You made a very specific claim that "stock-to-stock" a top swapped L36 makes 247hp. First thing that I want to point out about that is that not every engine will make the same hp, even if they're two Series II L67's. One might make 237hp and the other might make 243hp. Some engines might not run "perfectly" from the factory and other engines might be factory freaks. It's the same thing with every engine. Maybe the top swapped L36 was a factory freak before the top swap, maybe not.

The next thing that I would like to do is ask, do you have any documentation of a stock L36 being top swapped with nothing but stock L67 parts on an engine dyno before and after? If anything I would expect that top swapped engine to have a bit of KR because it isn't properly setup in the first place and I wouldn't be surprised if it made less hp then a stock L67.

Lastly, my point about an L67 swap making a bit less hp then a top swapped L36 is because there are very few L67's running stock compression making more then 350whp. To be fair however, I will concede that you could make similar power, if not the same power, as a top swapped L36 if you raise the compression in the L67. How would you do that? You could mill the heads and block and install thinner head gaskets too. But 3800's need compression or else they make poor hp.

 

Let me try to clarify my comments...

What I was trying to point out is that the increase in horsepower purely from the compression increase between the L67 and the L36 is small... that's not from engine dyno numbers, but purely from the formulas used in engine building... it's not exact but will give a very good approximation of the HP change from a change in compression ratio

Here is one such calculator: Wallace Racing - Calculate New HP From Change In Compression Ratios Calculator

Now, as you point out, no two engines will yield the same results... but on average, the L67 puts out about 240 Crank HP and the L36 puts out about 200 Crank HP. Using the calculator above (or the actual formulas), 240HP at 8.5:1 compression yields about 247HP at 9.4:1 compression

You will obviously do better than that on the L36 since you have to tune it for the M90 and no one will tune it conservative like GM does from the factory, so you will see a larger gain in HP than the theoretical 7 HP (and likely more KR). If you tuned a stock L67 for maximum performance and did the same on a top swapped L36, you would expect the same 3% increase in HP from the L67 to the L36 due to the higher compression ratio

BBEngineer

 

That sounds good to me Thank you for the clarification!