Looking for opinions on engine build

67Straightsix

Well-known member
I've been putting together a turbo engine for my wife's 67 mustang. This car is mostly a street vehicle, but may see some open track time :LOL: I'm going to line out what I've got going and see if anyone can see any major mistakes or things I've overlooked. I'm starting to wonder if my cam selection is correct. Any advice would be greatly appreciated.

200 block - bored 30 over
forged pistons
stock rods and crank
ARP bolts
cam - 264 int / 264 ex / 110 ls
milled the intake off the head - similar to modlog
gonna run GT286R turbo
fuel injected - leaning towards megasquirt for engine management
36lb injectors
63.5mm throttle body
T-5 transmission
3.00 rear end gears
I'm keeping the boost at 10psi (90% of the time - max 15)

Thanks,
Ryan
 
If you are going to run 15 lbs of boost with the stock exhaust manifold the valve overlap needs to be minimized by using a wide lobe separation angle 112* - 114*

It looks like the plans are to run the engine up to 5000 rpm max and make just over 300 hp.
I'm assuming minor port clean up at the most with stock valves?
The 264 cam you listed has a .050" duration of 214* which is way more than you need.
If you want fast spool up then the .050" duration needs to be limited to just over 200*

A cam with 202* - 204* .050" duration on a 114* LSA with around .450" valve lift would work well.
The small amount of valve overlap will give you a very smooth idle and great fuel mileage when your foot is not in it.

Comp cams would be able to make a custom cam as well as several other cam companies.
Sometimes Comp has a tendency to spec a little more duration than needed for street turbo application.

You did not list an intercooler?
At 15 lbs of boost the outlet air temps will be near 240 degrees F.

The GT286R needs to have a 47 mm compressor inducer wheel diameter in order to supply 35lbs/min with a safety margin.
For fast spool it should come with the .64 A/R turbine housing.
 
Thanks for the reply. I'm sorry I should have given a little more information on the head. I'm running 1.46 intake valve and 175 exhaust - lots of porting work. Also building a header for the turbo. I'm definitely running an intercooler.

This is my first turbo build - still learning all the ins and outs. You're input is very helpful. I'm trying to find any mistakes before I build the motor.
At the moment I'm working on my intake - trying to figure out runner length and plenum size.
 
What is the max rpm you want to make power at?

Did you have a HP goal in mind?
 
I want the horse power at 300+ and because it's mainly driven on the street, I'm trying to keep the peak rpms to 5000. I know I've probably gone overboard on the head work for the rpm range - I'm walking a thin line between reliable everyday driver and my desire for horse power ;) I'd like the car to pull hard off the line and out of corners. I'm specifically building this car to do well on mountain roads and at the road racing track (not so much drag racing). The cam info was very helpful and we're on the same page as far as the turbo
 
The head work will help make more power with less boost.

Was most of the attention in the bowl area around the valve guides and you didn't take much material off the port walls to maintain good velocity?

What compression ratio are you planning for?
 
I'm having the porting work done by a machinist friend I trust. When he's done I will post the flow numbers. The head is a 72 casting.

Just got my pistons yesterday (felt like Christmas) - I'm thinking about 8 to 1 compression because this motor will be run on pump gas and I'm worried about detonation. Opinion?
I haven't done any machining for deck height yet.

Started building a plenum type manifold with straight runners, but am now second guessing myself - any thoughts?

I did contact Comp Cams - got their reply this morning. They suggested 112 degrees LS instead of 114 - otherwise you were right on target - thanks.
 
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