I do have a regulator and my pressure is at 43psi key on engine off.  114 lobe separation from Isky cams.  I did get it tuned and ready for some pulls on monday.  I had to replace my plug wires and header gaskets.  Had some copper ones built and installed them but my headers are not machined perfectly straight so they did not seal at all.  Had to build new ones.  Did a lot of tuning on the dyno and then test drove to adjust some small things and now it should be ready.  Are you guys still using that port fuel injection I am interested in if that is working well.  I think I could get better response with that.

Yes, we are using that 8-point injection. Everything else will change for summer. Different block, new con rods, new pistons, new cam, new heads (but still iron heads), roller rockers, maybe even twin turbos, 90 lbs/hr injectors... So, lots of questions, but we are sure that the limits of Y-block are yet not discovered .

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

What kind of pistons are you thinking of using or what compression ration are you shooting for.  I think my compression is higher that I think.  I would actually like to lower my comp and crank up my boost to like 20-25 psi.  Once we get mine tuned in on 10psi and it holds up I garuntee we will TURN IT UP!!!  There is no such thing as carbon in our engines. 

Very light forged SRP pistons and compression ratio close to stock 8.2-8.5:1.

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

It looks pretty good until 3900 then something goes wacky. Have you tuned it well without the boost yet?


Lawrenceville, GA

I am going to buy some different heads to lower my compression ratio.  We can't get any timing into the engine.  If we advance the timing it will hardly run and if we retard it, it will backfire.  We calculated our compression @ about 11.5-12:1. I am running E85 but I under boost I don't think we can keep the combustion chamber under control. 

 We actually found a problem with my crank trigger setting in my software and seems to run better.  Still have some mid range tuning to do but I am really happy with the results.

Interesting... . Your torque curve really begins from 4500 rpm? Is there anything below that?

351 hp from rear wheel + about 15% more from the crankshaft. Not bad, but I think you have lots of more to come after you get everything working.

Our engine gave best torque at 2600 rpm 630 Nm at engine dyno with single turbo and 0.7 bar pressure. (465 ft pound/10.1 psi). 329 hp / 5000 rpm. Our single turbo just was too small and exhaust back pressure was about 1.07 bar / 15,5 psi . Not so good and that's partially why HP was so small.

 Seppo from Järvenpää, Finland
www.hollowheads.net (just click the hole in the head to proceed)

There is a more smaller acceleration pulse times with 8-point, but I dont think there is not so much differencies.



Fuel/air-mixture is really fast moving stuff on high RMP's, so injector place is not so important.


Hyvinkää, FI

I started that run at high rpms because we needed some more tuning at low rpm under high load.  We have tuned it in better since then and it made about 380 lb/ft at the wheels at about 5000 rpms.  We have a lot smoother power curve now I pulled out some fuel.  I found that my engine likes about 12.2:1 afr.  We initially tried to tune to 11-11.5:1 under full load and boost.  It is not happy there.  Pulled some fuel out and now it runs better.  Didn't do anymore pulls on the dyno because it's running great and we have a evening cruise this weekend and I didn't want to miss it because I wrecked something.  Will do some more tuning next week.