truck on the dyno yesterday. There were/are several things that still need work(fuel pump,o/2 gauge,

changing to E85, etc) but it put out some decent #'s after he played around with it.

               Air temp 85 degree's, inlet temp at turbo(no intercooler) 259 degree's and 60% humidity

it made 468 ft lbs (rear wheel) @ 4500rpm and 402hp @ 4500rpm. I was "Happy" to say the least

and Reed says with a litle more fine tuning and maybe with E85 it should do better...I drive this

thing a lot, so I'm not going with any radical changes....

                                                              Bill

We couldn't rpm more than 4500/4700 because lack of fuel pressure...

When we ran our engine at the dyno, we had 0.7 bar (10 PSI) pressure and the intake air temperature never exceeded 35 degrees celsius (95F). More heat means more risk of detonation.

Good numbers, though .

We are currently running the truck non-intercooled...hence the reason for the charge temps being so high.  Keep in mind this turbo system was never designed to run this good...it was originally done to fit the stock 292 and make ~350 HP

The current setup uses a blow through carb (holley 650) with boost referenced power valves (BRPV).  I had a fit getting them to run on the original engine, and now the new stroker puts a much different demand on the fuel system it is in a much worse state of tune. 

I was also fighting a bad fuel pressure regulator, the diaphram had ruptured allowing fuel to be pulled from the intake vaccum reference port.  I replaced the regulator only to find out the pump is going bad and cannot deliver the required fuel.

This week I will be changing the fuel pump and also the BRPV's and jets in hopes of gaining control over the fuel curve.  The best pull I made on the dyno started with a 10.2:1 AFR, and slowly leaned itself to 11.2:1.  We like to target ~11.8-12.0:1 AFR with a carb to make peak power, so the HP curve will get quite a bit better once the changes are made.   But if the carb will not agree with me 100%,  it will be changed in favor of EFI.

I am pretty impressed with how easily the little engine made power, and since the original turbo system was never intended to be run this hard I might have some updates coming in the near future.

The current setup is (to the best of my knowledge!)

315" via off-set ground crank from Ted, H-beam rods, forged pistons (~9:1), Un ported factory "posted" heads, stainless valves, custom Isky cam specified by me, factory un ported cast iron 4V intake, 60-1 TO4-B 60mm turbo (all late 1970's technology, for the nostalgic look :cool

Dad drives this thing everywhere...but now that I have my hands on it along with a DynoDynamics full load bearing dyno (thanks to Tommy at Performance Engineering for loaning it to us while his shop is being built!!) it will be getting some much needed updates to the fuel system and turbocharger setup.

I will keep you guys well updated...and hopefully make some useful contributions to the forum!

Thanks for looking,

Reed

So here it is...

  I will find the cam card later this afternoon and post up the numbers.  I am working on a few different ideas for the Y-Block camshaft, so having your camshaft info will be very helpful in the long run.

 Normally with a low flowing cylinder head similar to the Y-Block, you can start to open the intake valve around 22-24 BTDC and make really good top end power.  Of course the more boost you are running and the higher the head flow, you want to start opening the valve later in the cycle, say closer to 20-18 BTDC. 

 The exhaust valve opening is an event that I love to work with, only because it has so much to do with the engines ability to make a turbocharger respond.  In all engines that I have tested, you want the exhaust valve to open somewhere around 72-78 BBDC.  The problem with opening it earlier with an exhaust port that does not flow well is heat contained in the exhaust valve.  You really have to work with this event based on exhaust port flow, header design and turbine wheel/housing setup on the turbocharger.  We do have one engine (SBF) opening the exhaust valve right around 81-82 BBDC, but it has a very aggressive exhaust port flow (360 cfm).

 All turbocharger camshafts that utilize late intake openings and early exhaust openings seem to like making peak power later in the RPM curve, especially if the heads flow very well.  My theory for this big of a camshaft in the Y-Block is based solely on the heads weaker flow numbers, and hopefully the ability to add duration will prove beneficial to making a nice power number with a turbocharger at very low engine speeds.

I apologize for all the info at once, I am very excited to see what we can learn from all of it!

-Reed

Bill & Reed.  Great numbers and thanks for posting.  If taking a 15% driveline loss into account, that figures out to 473HP at the flywheel.