This is the crate engine I am getting

CHEV 350 - New 375HP 4Bolt Vortec Motor.100% new
New motor comes with Vortec L31 64cc heads, 4BLL alloy performance inlet manifold, flat top pistons, bowtie style rods, double row timing set, HV oil pump, nodular iron crank, 375HP @ 5700 RPM, 407FT LBS torque @ 4300 RPM

Will be getting the SDPC base plate to use TPI on this engine. The cam in the above engine is

Std bore, hyperutectic pistons, heads i 1.94 & ex 1.5 valves, cam specs .470/.480; 224/230.

What do you think about the cam in the engine now?

Would I gain anything putting a LT4 hot cam or is that a NO NO with TPI? I would probably need to get the heads machine for the extra lift?


It might be worth getting comp cams to grind me a specific CAM profile but I have no idea what I would ask for to suit TPI. Also a streetable stall convertor is also an option to go along with the cam. Any suggestions??

T

 

You would most likely have to have the heads machined for the extra lift of the hot cam but I think you would see 400 hp with this cam as long as you have an aftermarket TPI manifold such as the holley stealth ram or mini ram. The only problem is that I dont think you can get any other TPI manifold than the SDPC unit for the vortec heads. I think if the motor actually makes 375hp with their intake I would stick with the cam you have. It sounds like it will make nice numbers and be very streetable. Good Luck.

 

Cam thats in it should be plenty enough to get in trouble with. I wouldent touch the engine unless there was somthing that needed to be done down the road.

 

Don't plan on this cam working well with a stock TPi computer. A GM Hot Cam is a Hydraulic Roller. will need machining and specific retro-fit valvetrain parts if yours is a flat tappet motor now.
Can't tell from your information exactly but I'd guess its a comp cams XE268H-10 hyd flat tappet cam. (could be different). Is it a Hyd flat tappet or a Roller in there now?
need more info.

Hyd and hyd rollers that are TPI friendly, generally are low overlap, High vacuum grinds ground on 112 to 114 LSA. the longer duration ones generally need computer chip re-tuning. If you want a cam that will bolt in and work well without major re-programing a chip, contact Comp Cams or Crane Cams for a specific grind recomendation.
It will be on the mild side but 375+ hp is well within reach. You'd do best to consider on of the short(er) runner manifolds like a RamJet or Mini Ram III for best performance from your Vortec headed motor, as the stock TPI long, small cross section runners and restrictive manifold will limit power.
Where are you getting this Crate Motor from? Sounds different than the stuff GM is offereing. ( Cam)

 

I would keep the GM roller cam that comes with the motor and install 1.6 roller rockers instead. You would then get about 3 degrees more duration along with .500/.512 lift, and, a few more HP from reduced valvetrain friction. Get the Scorpion narrowbody rockers for about $225.00.

 

Wow thanks for the help fellas.

I should add that if need be I can tune the chip so that should not be a problem.

The only reason why I was asking about the CAM is the the crate engine as is now has a inlet manifold to suit CARB. So I was not sure if the CAM in there now would be optimal for TPI. It probabaly would not be 100% optimal.

So you guys suggest I get it like it is and add some 1.6 roller rockers and it should be cool?

Having said that would I need to get the heads machined if I get the roller rockers with the CAM that comes in the engine?






F-BIRD'88 - You are correct in asking that it sounds different to what GM is offering. This engine is in Australia so maybe we get different stuff here

Also is it worth the extra money ($500AUD) = ($350USD) to get the steel crank instead of the IRON one in there now?

I am pretty sure the CAM in there now is a Roller I am going to ring up and ask about that.

The main question I had was the CAM seeing as the engine is set-up for a CARBIE would it be a okay CAM for TPI.

Mike

PS. I think I am also going to have to convert to a 1 piece rear main seal as I have an 1986 IROC with T700R4. Not sure how much hassle that is? New flexplate?

 

I just called them up now.

The CAM is not a roller cam but they can do a roller cam same specs etc for an extra $300. Worth it?

Said he would give me a flexplate for $100 if I buy the engine.

Dilema time should I spend the extra $300 on the Roller CAM or stay with the flat tappet.

Should I spend the extra $500 on the Steel crank?

Thanks,
MIke

 

I'd keep it a carbed engine. You'll get more power easier and enjoy the simplicity of design and low maintenance of carbs compared to tpi setups. (Not to mention major cash savings.) A QJet would work really well on that engine and give you probably better mileage than tpi. Indeed, the intake is clearly designed for a Rochester

 

The cam will likely not be all that TPI friendly.
What is the LSA (lobe separation angle)?

I would substitute a different milder cam for a basicly stock TPI.

 

Noy sure of the LSA I could just tell him to put a CAM in of my choice or I could buy it without a CAM and install my own.

The TPI would be ported to help a little.

I am not going to go with CARB even though tit is easy but I like the TPI and have all the gear to tune it so it should not be a problem.

What CAM would be a good perfomer for a vortec engine with TPI. I would like something around 400hp if over the better.

 

If you want 400+ horsepower:
Scrap the TPI manifold idea. The long, small cross section of the runners really restrict the power potential of this motor. Your not going to make 400+ hp with any cam on this motor even with porting . It may look pretty but TPI is the wrong configuration for high horsepower output.
Easier to work within the laws of physics than against them. Get a short(er) runner manifold.

You need to do some more research.
If you want a 400+ hp motor why are you buying a 375hp motor?
If you want a EFI motor why are you buying a carbed crate motor?
If you want 400+ hp why are you trying to do it with a intake manifold that is designed for modest horsepower?
if you want a roller cam ( LT-4 hot cam) why not get a "roller block" motor to start with?

 

Well the reason I want to get the 375hp engine is that it is close to 400hp and I thought with maybe some changes it could get to 400hp or just over.

We don't have that many options here unless you spend big $$$. I know that in the USA you can get 450hp engines for like 3K unfortunatley not the same here.

All that is needed is to put on the SDPC base plate and it will be an EFI engine as long as I find a good CAM to work with the TPI, if this CARB cam is not optimal.

I don't want to spend too much $$$ and try and work with what I have TPI etc.. I mean if it falls below 400hp or I get 375 no big deal.

 

Use the LPE 219 cam, it is proven in tpi setups, you will be happy with the results.

 

The problem, as Russ points out, is the tpi induction system. It just won't support the RPMs necessary for that engine to develop the 375 hp it comes with. The engine doubtless produces 375 hp at somewhere around 5500 rpm but you will be lucky to hit 4500 rpm with a tpi system--and that's going downhill.

Thus my recommendation of keeping it a carbed engine, which can easily support those rpms. Antiques that they may be, there is a reason that most high hp engines use the good old carburetor.

I don't know if anyone has ever gotten a factory L98 induction system to turn that fast or produce that much hp.

Sorry

 

Agreed.
Maybe the price is about right, but you'll really be sorry with the results when you turn the key.
You can only adjust a chip so far on a factory system and only the mildest of "carb intended" cams will work. Then you open another can of worms when you find that the injectors are maxed out.
For an example of what everyone is talking about, go to Compcams web site and look at the cams for injected versus carbed motors.
Two examples in my drive alone.

Carbed motor. 10.7 c/r
2.08/1.74 valves
238 degree @ .050 cam with .505 lift and 108 sep angle

Injected motor. 9.7 c/r
1.91/1.60 valves
Comp XE 262/268 custom .495 lift
115 degree sep angle.

 

Hi mate i am also in Australia and purchased this engine or sounds very similiar....ibrought my engine from Suburban imports......although i must sat say i was a little disapointed to find it doed not have a roller cam as told by the seller. How is the engine mate do you have it in the car.....would really like to talk to you more ....do you have a phone number or email address.....or call me on 0408 246151.....cheers Tyrone

 

Since it is a Carb engine now... It seems to me that the thing to do is to pay the $300 to have them install a Roller cam that is more suited to TPI.

cam specs .470/.480; 224/230 with 112 to 115 LSA would be fine for TPI. A bit more lift and a bit less duration perhaps...

 

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