Twin Turbo 318 or Twin Turbo 225?
I'm definitely going to push as much boost as possible. I'm going to do a ton of little "tricks of the trade" to get a solid base horsepower with approx 8:1 compression allowing me to force a lot of air through it. I just gotta make sure the bottom end can handle the boost.
I found Howard's offers custom ground cams for the /6 through summit. Hopefully I can get what I want out of the cam.
The following is just what I have learned through reading on here and off the slant six forum (
www.slantsix.org) and shouldn't be taken as anything else than
JUST my opinions, as I have yet to get my own car to the strip.
I have included some photos of my stuff so you can see what I am trying to do. This '64 Valiant will see very little, if any, street time, with the bulk of its life being spent on the drag strip.
I built a clone of the engines in two very successful cars that paved the way for the rest of us (who decided to follow their paths.) None of this was MY idea; I am not that smart, frankly.
Here is a fairly complete set of specs for what I did (remembering that I was simply copying what I had witnessed to actually work, in spades!) Tom Wolfe and Ryan Peterson have these two engines, and they each make a little over 500 horsepower at around 25 pounds of boost. That pushes Ryan's '66 Valiant at 2,800 pounds, into the tens at 127mph with a power-absorbing 727 transmission aboard.
See in action at [ame="https://www.youtube.com/watch?v=7QzUfV8iTpQ"]Turbo Slant Six 10.74 @ 127 mph 7-19-10 - YouTube[/ame]
Tom's car is a bit heavier at about 3,300 pounds, and ran an 11.02 at 120 mph into a fifteen mph headwind.
See that run at: [ame="https://www.youtube.com/watch?v=EAxRmoDgsdY"]Turbo charged Slant 6 11.02 @ 120.56 - YouTube[/ame]
You can see why I wanted an engine like that:
No EFI (just a blow-thru Holley 650 cfm 4bbl,) No exotic ignition, only a 5,500 rom redline, a 2.76:1 rear axle ratio (hiway gears and a 904 tranny in Tom's car.
Here's the parts list. I tried to build as close a copy as I could, varying mainly in the intake manifold, probably a mistake on my part.
1964 Valiant V200 4-door sedan, 225 slant six/904/8.75" rear (3.55:1, Sure Grip)
Block was bored .065" and fitted with Wiseco forged pistons, .167" down in the hole, which gives 9:1 CR with a stock, un-milled head and an un-modified combustion chamber. Steel head gasket, .022"-thick... ARP 220,000psi (special-order, head studs, K-1 198 rods that use ARP rod bolts, forged crank turned .010"/.010" and balanced.
Head is ported and is fitted with oversize valves (1.75"/1.5") and utilizes a homemade header, and an AussieSpeed long-runner intake manifold with a Holley 750cfm double-pumper carb that has a boost-referenced power valve and other blow-thru modifications.
Cam is a Bulllet (brand) flat tappet, solid-lifter regrind with .484" gross lift with stock, 1.5:1 rocker arms; 210/210-degrees of duration @ .050"-lift and has 115-degree lobe separation. The valve springs are new, 340 springs to which a small (weak) inner spring has been added. They supply 132-pounds on the seat and 310 open. Rocker arms and pushrods are stock (1.5 arms.)
The oil pump is stock, but a Moroso "Accusump" will be used in service (ads 3 quarts to the system.)
Red line 5,500 rpm
Ignition is by means of a stock, electronic "Lean-Burn" Mopar distributor with no vacuum canister, and no centrifugal advance mechanism of any kind (the distributor provides NO advance of any kind.) Timing is set at 18 crankshaft degrees and stays there. No "curve." Don’t expect ANY reasonable gas mileage out of this setup; it’s strictly for racing.
An MSD 6-AL II module is used with an MSD Blaster II coil.
As I said: this is a race car; that "tune" on the distributor might not work well on the street.
Oil pan was deepened 2.5" (sump only) and baffles added to preclude starvation under hard deceleration. It has a modified pickup for accommodating the deeper pan.
A SnowPerformance Stage I Boost Cooler alcohol/water injector was added to battle the tendency to detonate under boost. The thing starts spraying at 8 pounds of boost; #2 nozzle. A front-mounted intercooler is used to help cool the charge.
The turbo is a 66mm Turbonetics (T-4, I THINK; not sure.)
An appropriate size external waste gate was fitted to the header.
The transmission is a “built” 1973 Slant 6 904 with a 2.74 first gear and a reverse-pattern, full-manual Turbo-Action valve body.
The converter is a 3,500rpm-stall, Hughes
Heavy-duty 7290 U-Joints are attached to large-size yokes on both ends of the 3"-diameter driveshaft, while the axles are Yukon high-strength units with Green bearings.
"CalTrac" traction bars, 50-50 shocks and weld-in sub-frame connectors are used with 90-10 front shocks and aftermarket disk brakes in front.
A six-point roll bar was welded in and a driveshaft loop added.
The fuel system consists of a Summit 8-gallon fuel cell, two inline filters (one before and one after the Walbro GSL392 electric pump,) and an Aeromotive boost-referenced fuel-pressure regulator, set at 6psi., with a half-inch return line to the fuel cell.
The car weighs 2,680 pounds without a driver. It has a fiberglass hood, battery in the trunk, no front bumper, no rear seat and light-weight front buckets. A Turbo-Action "Cheetah" floor shifter is used.
It has an electrically-driven fan and water pump.
Slicks are the biggest I could get to fit (9"-wide, 26"-tall on 8"-wide rims.) They are Hoosiers.
Coil-spring accessory "helper springs" raise the rear for (needed) added tire clearance.
If my engine can produce within 100 horsepower of what Ryan's and Tom's do, I'll be very happy. This is my first attempt at a slant six and a first-ever turbo motor, so I am just learning.
My car is just getting finished and ready for some shakedown runs. Wish me luck; I’m gonna need it!!! :prayer::prayer::prayer:
My feeling in that twin turbos in an application like this is an unneeded complication (as opposed to just one) and wouldn't serve any performance-related purpose. Granted, the bling factor would be awesome, but it might not be worth the considerable extra effort; this thing is GOING to raise a lot of eyebrows anywhere you show it off...:D
That's about it.
It's a lot of time, a LOT of patience, and not a small amount of money to do it right, but I think the dividends it pays are well worth the effort! You can outrun 90-percent of tythe V8 swaps with a well-built, well-tuned deal like this, and the few you can't outrun will have more money in their setups than you do, likely.
Have fun!!! That's the whole rationale behind all this hoopla...:cheers:
