Real tech discussion on design, fabrication, testing, development of custom or adapted parts for Pontiac Fieros. Not questions about the power a CAI will give.
No expert on the 3800 but I would be shocked if GM didn't have tweaks to the 3800SC version of the engine to better handle boost.
Chris-Nelson wrote:
Although, to buy a used stock NA3800 is much cheaper usually than a stock used SC3800. So, maybe it would be easier and cost effective to use a NA3800 with the SC MAF and computer.
I'm no expert either, but I believe the only thing different about the sc motors is the rods and pistons. This is penny pinching GM were talking about here. The 3800 block is the same casting I believe, not sure about the cranks.
crzyone wrote:
You can buy some very strong small journal sbc rods, and custom forged pistons only cost in the area of $500-600. So, $1000 worth of internal work to a 3.4dohc and you will have one kick ass motor.
However, up to 500hp, the 3.4 will win IMHO. Build the bottom end like Cryzone mentioned (About the same price as a 3800), and then turbo it with a good system, and 500 isn't at all unreachable.
It is funny, turbo 3.4s are becoming very popular all of the sudden. There are about 5 running, 2 impressive dyno numbers out (263 and 212whp), and there are probably 10 in the workings, including mine, both of mine... :scratch:
500? You really think the stock cast crank, secured by four 2 bolt caps is good for 500 HP? I'm not buying it.
To attempt 500 HP, I'd want the DIS 2.8 crank (shorter stroke on same size journals = stronger crank) with 4 bolt center caps and probably a home-made main bolt/stud girdle. ARP fasteners.
What's the 3500 crank got that's special? What stroke is it? What stroke will the 3900 have?
Since when is a mid-200's dyno sheet impressive?
While rods/pistons may come to $1000, it'll cost at least double that to put together an engine that has a chance at making 500 HP. There's a lot more to power than stout components.
crzyone wrote:I'm no expert either, but I believe the only thing different about the sc motors is the rods and pistons. This is penny pinching GM were talking about here. The 3800 block is the same casting I believe, not sure about the cranks.
I'm pretty sure this is correct. The stock rods, when shot peened and polished, have been proven to be good for 600+ HP in a drag race application.
If you want the extra margin of safety, L32 (3800SC S3) conrods are MUCH beefier still.
So... L32 rods, forged pistons, decent rings, etc and you have a 600+ HP short block for much less than an equivalent 60 degree engine. The 3800 already has the bottom end fortification (6 bolt caps) that will have to be added to the 60 degree.
crzyone wrote:
You can buy some very strong small journal sbc rods, and custom forged pistons only cost in the area of $500-600. So, $1000 worth of internal work to a 3.4dohc and you will have one kick ass motor.
However, up to 500hp, the 3.4 will win IMHO. Build the bottom end like Cryzone mentioned (About the same price as a 3800), and then turbo it with a good system, and 500 isn't at all unreachable.
It is funny, turbo 3.4s are becoming very popular all of the sudden. There are about 5 running, 2 impressive dyno numbers out (263 and 212whp), and there are probably 10 in the workings, including mine, both of mine... :scratch:
500? You really think the stock cast crank, secured by four 2 bolt caps is good for 500 HP? I'm not buying it.
To attempt 500 HP, I'd want the DIS Boat Anchor crank (shorter stroke on same size journals = stronger crank) with 4 bolt center caps and probably a home-made main bolt/stud girdle. ARP fasteners.
What's the 3500 crank got that's special? What stroke is it? What stroke will the 3900 have?
Since when is a mid-200's dyno sheet impressive?
While rods/pistons may come to $1000, it'll cost at least double that to put together an engine that has a chance at making 500 HP. There's a lot more to power than stout components.
I said 500 with a built block, which includes the 3500 crank, which is forged from the factory, and apparently pretty strong. It hasn't been used yet. The 3500 is the same stroke, I believe the 3900 is larger IIRC.
Mid 200s aren't impressive, but for the 3.4, they are. Not becuz they are high, but becuz they are the highest yet. There was a time when 200hp SBC's were king, and impressive. We are in that age, except with the 3.4 annd 40 years later...lol...From here on out, they are only going up. Excluding short runner, Michael set the bar at 218whp, which was blown by Tim's 263, than matched by Kevwood's 257. Its taking time, but the DOHC is really picking up lately, especially with the Fiero crowd. I can't wait to see some of these new 3.4 turboes dynoed! 500hp is possible, it is just going to take time, and money of course. Upper ceiling? For now, yah, I;d say 500 is realistic, but with time maybe that will get broken.
A two bolt SBC bottom end is commonly considered good for 450-500 N/A HP, and it has 5 caps with bigger bolts. Turbo HP is gentler in terms of RPM loading but more harsh in terms of torque loading, which really puts the tension on the cap bolts.
As I said, I'd want to use the 4 bolt caps from the bowtie block on the center two locations and whip up a bolt/stud girdle to tie the outer two to the center two.
While a 750 HP turbo 60 degree was built by Ryan Falconer, that was a $30,000 engine and I'm pretty sure it used a bow tie block.
The production block just may not be up to the task. You may end up blowing head gaskets because the block deck just doesn't have enough rigidity to hold them... or some other problem that can not be overcome on a production block.
crzyone wrote:Like Will said. A crank can be bulletproof, but the next weak link is the caps. How can you have a built bottom end on 4 2 bolt caps? Crank walk?
Since nobody is close to 300hp let alone 500, there are alot of variables to look at.
2 people have already broken 300hp, with a third very close...
But yah, we are miles away from 400, maybe I'll be the first...
Actually oversteer was refering to the 3.4 pushrod becasue the 3.4 dohc can and has been built to 200 hp. correct me if im wrong on this oversteer. I believe the point he was making was that the 3.4 is easier to swap and lighter.[/quote]
Yes I was refering to the Pushrod 3.4 not the 3400 or the TDC. If you could get the 3.4 to 200 with a few mods, I think it is a better all around motor, fits better, easier to swap, and will look alot more stock than the 3800, just needs comparible hp.
