Was this posted here before.
Found it posted in the Racing forum.

Was told it's Mike Simard's monster build.
Mike Simard's 427 928 motor




Cool seeing the atomized fuel being su-uuuuucked into the intake valves.

Really glad guy didn't drop his flashlight or anything into the open throttle bodies.

 

That's pure grade A 928 **** right there.

 

Yeah. That one gets a five out of five stars 928 ****.

 

WOW that video ROCKS....pure 928 ****.....

 

Here is the original thread on the motor in that video:

https://rennlist.com/forums/928-foru...ject-pics.html

 

IT LIVES!!!!!

 

OMG! thats insane.

Ill read the story again, but is that the louie ott ITBs??

427?? if 6.5 liter is 390ci, 427 is 7 liter. WOW. But, how. sleeved 113mm bores? 103mm stroke?

I hear it is racing this weekend at road atlanta. anyone going? PICs!!!! race or opentrack, or time trial?

 

Not just ****, I see great potential with better lighting to learn about fuel flow.

Anyway, I want more than 46 seconds.

 

Hi!
I didn't realise that video would have been interesting to anyone. I put it on you tube and didn't tell anyone and Abby immediatley found it!

The engine has been running for a while including already blowing up and being rebuilt once.
I had a valve break at the keeper groove which was unusual. It was a TRW 968 replacement which is common from all sources incuding from Porsche in Germany. I'm sure that the TRW plant is in China for my valve by the markings and finish. The 3 groove design isn't optimal for heavy use because it doesn't clamp on the stem but is loose to allow rotation. With 80s vintage German Porsche parts that's no problem but my TRW valve was made with looser tolerances and the 3 grooves were just slightly looser than originals. That allowed the retainer to rock quite noticably which will break a valve at the keeper groove. That leaves the only reliable valves as custom Ferreas or Supertechs.
It especially sucked because everything had otherwise come out well with no issues but no blown up engine is without a silver lining because you get to make improvements! It was also nice to see how all the new untested stuff did by taking it apart.
Everything aside from the valve has worked well. The sleeved design now gives me a warm feeling of confidence, it's the last thing I worry about. The cams, ITBs, dry sump, COPs, flyweel/HTOB all seem to just fine.
It was a treat to hear from you guys, thanks!

 

Hi Mark.
The car races w2w in NASA. I 'raced' it last year with the original 4.5. That engine dynoed @ 229hp which put it in GTS3 with some serious competition.

I've installed inlet restrictors on the new engine which keep it at 442hp. That puts it into GTS5 which is the most much power/weight possible without being in SU. There is a GTSU class but it winds up being various GTS classes that didn't submit their dyno sheet in time/yet, not really close competition there. All GTS cars are to be tested on a Dynojet and the dyno operator signs a declaration sheet to make the classing official.
The NASA GTS series is really growing with the west coast just now starting. The simple weight power rule is like early CANAM in that pretty soon some interesting stuff is going to show up I just saw a late model Grand Am BMW that had GTS5 markings! Those cars can simply adjust their drive by wire throttles to put out the optimal amount of power for a class, it was bound to happen...

BTW, my engine is 109mm bore x 94mm stroke. I designed the ITBs for the engine.
I should add that this engine has no business in this racer but I couldn't 'not' install it since it's been sitting around needing to go in something.

 

By Mike Simard
Hey Mike sorry to hear of the blow up but you make a really good point about the TRW valves, I sold some genuine 968 valves to fellow in England and I made that point to him. I never thought that the TRW valve would be as good as the OEM german valve. The fellow who made my valves made a similar point to you in respect to the triple groove valve. Not many valve stems are made from a material that this can work. In fact he told me they have to specially harden it also. If the material is slightly off it will wear more too. Also three cuts in the stem instead of one and the triple groove doesn't clamp like the single groove.

I have Ferrea valves for the exhaust in my stroker but I have been told to be careful with them. Zanzi make some steel valves, I have not heard any thing about Supertech good or bad. Maybe anything that is machined right made from 214N EV8 or or better still EV16. Happy to put you in touch with my valve maker, all jobs are custom but quite reasonable.


At least you have piece of mind now.

Cheers Greg

 

Fu..Fu..Fu..WOW!

 

I just went from 6 o'clock to midnight. :-)

 

are you sure about GTS5 with inlet restrictors of 442hp? remember, they average out the greater numerical torque value with the hp number too!
What did the restrictors do to torque?

edit: I figure if you have 550rwt an 442hp, then your average is 495rwhp, so at 3000lbs with driver, you would squeak by the class spec. (of 6.0:1 on dots)

what about the race this weekend. are you going? dont forget pics and video!

mk

 

It's a pleasure to enter a torque discussion with you Mark!

Here are the rules with the power/weight table:
http://www.nasaproracing.com/rules/GTS-Challenge.pdf

The restrictors put me at 442 hp and 402 tq. That's 422 for the formula.
My race weight is 2780 (me, the car and some fuel)
That's a 6.59 ratio which is GTS5. It's also just enough to allow slicks which is nice because I can get free used slicks!