How to make my 5.7 GLi into a Gi?

[Bigdave196]

Ok, I just pulled the heads off of my 1997 Volvo 5.7L GLi powered BlueWater Monte Carlo. I lunched the head gasket between the number 3 and 5 cyl. The heads are getting freshened at a very reputable machine shop in Orem, Utah. Now from what I am told the engine has the roller cam in it. It is a TBI Chevy 350 and the heads are the 217 Cast 64cc Iron heads. The machine shop is cleaning, MagnaFluxing, and inspecting the heads before we go any further.

Is there a way to get the 280-300hp mark on this motor that it is capable of reaching without tearing into the short block? If so, what are your recommendations? It has a cast iron version of a "Edelbrock Performer style intake. After realizing what this motor is, I want to keep the TBI.

Thank you in advance.
Dave.

 

[Scott Danforth]

Cam change, exhaust manifold and riser change, and reprogramming to make use of the changes will get you a bit more power. However a stroker will net you a significant amount of power

 

[Bigdave196]

Who makes a decent manifold that isn't the cost of a rebuilt engine? Is it honestly worth spending $2100 on exhaust manifolds when I can rebuild the motor for about $2000 locally? Who do you recommend for a ECM Flash/Tune?

 

[Tail_Gunner]

Start this way Do you have heart shaped (Chamber's) vortec head's. If so big power can be made..a few more detail's please...I don't believe 217's are vortec heads stop everything your throwing good money at old underwear...

Post your serial number its on the engine....post the model number on your ecu..post your drive type with drive ratio

 

[funk6294]

The motors I am currently building had the 217 castings and they are not vortec. They use the 12 bolt intake were the center bolts are canted at different angle. I swapped the heads to vortecs on both motors since one of the heads was toast.

 

[Bigdave196]

Heads are the 217 Iron heads. 64cc chambers. They were the last head before the Vortec motors. If I change heads, then I will also have to change the intake manifold. I will find out tomorrow if the heads are still good or if I need to replace one. If I have to replace one then I am going to upgrade the heads. The engine is the Roller Cam GLi TBI injection Stock motor. Where do I find the drive ratio?

 

[Scott Danforth]

I would also recommend changing to vortec heads and intake. there are also some AFR heads that work much better than the vortec's and you can stick with your existing manifold.

 

[Walt T]

Scott is right, but personally I would go Vortec. How big is your boat? If its a < 20' Bowrider you'll MAYBE notice the difference. If it's a bigger boat save your cash for a stroker build as mentioned. No harm in making a few ponies with your current heads but don't bother with cam changes. The entire idea of more HP is to turn a higher pitch prop and do it through out the entire rpm range. This requires a substantial increase in torque at the low end and HP at the wot range. You're limited to 5000 rpms so don't fall for the automotive type upgrades. Don't buy expensive manifolds. You'll be disappointed. Go big or not at all. No harm in fixing up the heads they're off anyway. If it were as simple as a pair of 2K exhaust manifolds they wouldn't be able to keep them on the shelves. So plan a Vortec stroker with mirrors n stuff and you'll be smiling all the way to 5000 rpm.

Okay I checked Blue Water Monte Carlo, nice boat! You might feel a little more punch but seriously, don't put a lot of money in add ons. Its an expensive mistake. Changing to Vortec heads and intake wont do much as add ons without appropriate cam and pistons. The heads most likely will be 68cc which will change everything inside the combustion chamber, not necessarily for the better. There are 64cc, and 65cc Vortecs also. If you can get ahold of 351C or 371C Vortecs you can build a serious breathing motor.
So stay with the heads you have now and have them completely redone. Perhaps you have a leaky valve or seat and there will be an improvement. It's a really nice hull you have there and it's built for speed, so why do a half way build?

 

[Scott Danforth]

Walt, plenty of RV/Marine cams that will liven up a 350

 

[Bigdave196]

So stay with the heads you have now and have them completely redone. Perhaps you have a leaky valve or seat and there will be an improvement. It's a really nice hull you have there and it's built for speed, so why do a half way build?

Because the Short block is in pristine condition and I want to get back on the water by the weekend. This winter I will be doing a repower. Until I find someone who can reprogram an ECM for the power upgrades I don't want to have a boat that wont perform or hardly run because of these upgrade and not the porper programming.

Tailgunner-
Post your serial number its on the engine....post the model number on your ecu..post your drive type with drive ratio.

5.7GLI PLKDCE
4110145128
3868732


ECU reads as follow on sticker 57TBI/97L001
Then something on the side of the TBI reads BCTU 16184069

Drive unit SX-C1 1.51
4112031506
3868393

 

[Tail_Gunner]

Engine	5.7GIPLKDCE
Production period	1996-1997
Operation	4-stroke
Cylinder configuration	V-8
Bore (in.)	4
Stroke (in.)	3.48
Compression ratio	9.11:1
Displacement (cu. in.)	350
Power (hp)	250
Max engine speed (rpm)	4200-4600

It is a non vortec motor (heads) If you change to vortec getting a effective 350/400 hp if quite easy but comes with a cost around 2400. Yes you are right a new motor would be less from a on line sight cheapo motor's. there quality is dubious at best to many short cut's and no detail. Below is a link for tuning there as good as it can get.

https://www.obd2allinone.com/mefitune.asp

 

[Bigdave196]

Tailgunner. I was talking about having a marine 350hp motor built here. So going with Vortec heads makes that much of a diifference? I guess a cam change will come with this.

 

[Tail_Gunner]

yes so am i...talking about a marine motor that is. Yes vortec's make that much difference and yes a cam..spring's retianer's...a few insert's and you will have a very competent marine engine..solid valve train..and fuel efficient engine and by the way no maching. Google the xm270hr it has been used extensivley in marine for years...Hell i have one in a 4.3 its a solid as they come.