New domain: www.Speed-Talk.com

The forum is currently running on the new domain and server. The old domain will remain active for a while to forward any (less frequent) visitors.
Update your bookmarks to https://www.speed-talk.com or
https://www.speed-talk.com/forum/

Need some ideas on what happened

General engine tech -- Drag Racing to Circle Track

Moderator: Team

jet1
Pro
Pro
Posts: 441
Joined: Tue May 22, 2012 1:11 pm
Location: Alberta

Re: Need some ideas on what happened

Post by jet1 » Thu Jun 06, 2019 10:27 am

ptuomov wrote:
Thu Jun 06, 2019 10:18 am
Wouldn't that say that the exhaust cam is more likely to be too long duration than too short duration?
In my view it is maybe 4 deg long as well as the intake but its pretty close. We cam doctored the cam just to make sure nothing was weird from what the cam card said. Such a small engine that it doesn't take a bunch of cam.

User avatar
ptuomov
HotPass
HotPass
Posts: 2360
Joined: Fri Aug 07, 2009 3:52 am

Re: Need some ideas on what happened

Post by ptuomov » Thu Jun 06, 2019 10:33 am

jet1 wrote:
Thu Jun 06, 2019 10:27 am
ptuomov wrote:
Thu Jun 06, 2019 10:18 am
Wouldn't that say that the exhaust cam is more likely to be too long duration than too short duration?
In my view it is maybe 4 deg long as well as the intake but its pretty close. We cam doctored the cam just to make sure nothing was weird from what the cam card said. Such a small engine that it doesn't take a bunch of cam.
I may be talking out of my a$$, but it was my understanding that if the exhaust cam is either too long or too short it'll have a problem evacuating the combustion chamber. If it's too short, there's not enough time area to get exhaust out. If it's too long, the wave that's supposed to clear the combustion chamber during the overlap isn't strong enough. Someone more knowledgeable could confirm this (or not).

The other thing is that those headers are short enough that cylinder filling is going to vary per rpm and per cylinder. I am thinking that you're going to need more fuel in some cylinders than others. Less fuel to 180-degree exhaust blowdown victims at low rpms and less fuel to 90-degree exhaust blowdown victims at higher rpms.

In-Tech
Vendor
Posts: 2060
Joined: Wed Apr 21, 2010 4:35 am

Re: Need some ideas on what happened

Post by In-Tech » Thu Jun 06, 2019 12:25 pm

jet1 wrote:
Thu Jun 06, 2019 10:08 am
In-Tech wrote:
Thu Jun 06, 2019 3:58 am
jet1 wrote:
Wed Jun 05, 2019 10:29 am
Ok now that is confusing, with the cam we have now it hasn't even hit peak tq by 7300 rpm. I can see the 260 dur cam taking the heat out because it won't be making any power around 7000 is all.
I am pretty much out of room with putting egt's in each pipe. oil lines run on that side and a water manifold for the header not shown in the picture is on that side.
Did you mean peak TQ or peak HP at 7300? If boost is constant I have a hard time with it not making peak torque by 7300rpm.

Unlike a wide band, the EGT probe's can be on the underside of the header.
In this one we only went to 7200 and tq was still increasing at 11 psi consistent. The bottom of the header is where the water enters the header from the manifold. Sorry don't have a picture for that one.IMG_3738.JPG
If you are saying it makes 11psi boost @ 3000 consistent all the way to whatever rpm, I have a hard time with the torque number climbing above 7000 on a 2 valve engine, however, if it's say 10 psi and creeps higher with RPM then all is well. The 3hp per cu in is all in line at that boost and good.

If you don't want to modify your header you can always build a plate for the header flange for use on the dyno and shouldn't upset the packaging too much.
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl

User avatar
ptuomov
HotPass
HotPass
Posts: 2360
Joined: Fri Aug 07, 2009 3:52 am

Re: Need some ideas on what happened

Post by ptuomov » Thu Jun 06, 2019 12:50 pm

In-Tech wrote:
Thu Jun 06, 2019 12:25 pm
jet1 wrote:
Thu Jun 06, 2019 10:08 am
In-Tech wrote:
Thu Jun 06, 2019 3:58 am


Did you mean peak TQ or peak HP at 7300? If boost is constant I have a hard time with it not making peak torque by 7300rpm.

Unlike a wide band, the EGT probe's can be on the underside of the header.
In this one we only went to 7200 and tq was still increasing at 11 psi consistent. The bottom of the header is where the water enters the header from the manifold. Sorry don't have a picture for that one.IMG_3738.JPG
If you are saying it makes 11psi boost @ 3000 consistent all the way to whatever rpm, I have a hard time with the torque number climbing above 7000 on a 2 valve engine, however, if it's say 10 psi and creeps higher with RPM then all is well. The 3hp per cu in is all in line at that boost and good.

If you don't want to modify your header you can always build a plate for the header flange for use on the dyno and shouldn't upset the packaging too much.
I think he reduced the displacement a lot to make it within the class rules. As a result, the head, valves, and ports are massive compared to displacement. It makes sense to me that it wants to rev much, much higher than one would expect with seemingly small cams that are actually very big considering the head. Just my thoughts.

jet1
Pro
Pro
Posts: 441
Joined: Tue May 22, 2012 1:11 pm
Location: Alberta

Re: Need some ideas on what happened

Post by jet1 » Thu Jun 06, 2019 1:02 pm

In-Tech wrote:
Thu Jun 06, 2019 12:25 pm
jet1 wrote:
Thu Jun 06, 2019 10:08 am
In-Tech wrote:
Thu Jun 06, 2019 3:58 am


Did you mean peak TQ or peak HP at 7300? If boost is constant I have a hard time with it not making peak torque by 7300rpm.

Unlike a wide band, the EGT probe's can be on the underside of the header.
In this one we only went to 7200 and tq was still increasing at 11 psi consistent. The bottom of the header is where the water enters the header from the manifold. Sorry don't have a picture for that one.IMG_3738.JPG
If you are saying it makes 11psi boost @ 3000 consistent all the way to whatever rpm, I have a hard time with the torque number climbing above 7000 on a 2 valve engine, however, if it's say 10 psi and creeps higher with RPM then all is well. The 3hp per cu in is all in line at that boost and good.

If you don't want to modify your header you can always build a plate for the header flange for use on the dyno and shouldn't upset the packaging too much.
yup 11 psi boost consistent. I don't think it would pull psi boost at 300 rpm but once it gets boost it was 11 psi.
Great idea on teh extra flange though!

jet1
Pro
Pro
Posts: 441
Joined: Tue May 22, 2012 1:11 pm
Location: Alberta

Re: Need some ideas on what happened

Post by jet1 » Wed Jun 19, 2019 1:06 pm

Well a little update on this project. Installed 8 egt sensors in the headers and ran it at 15 psi boost 30 deg timing and 1000hp@7300 for a 4 min dyno run and egt's stayed below 1400f. All are very close so this thing seems to be finished. made one pull at max boos but kept the rpm low. 1382hp@6400 32 psi. would have been nice to see the power for bragging rights if we let it rev but didn't want to take any chances.

User avatar
ptuomov
HotPass
HotPass
Posts: 2360
Joined: Fri Aug 07, 2009 3:52 am

Re: Need some ideas on what happened

Post by ptuomov » Wed Jun 19, 2019 1:11 pm

jet1 wrote:
Wed Jun 19, 2019 1:06 pm
Well a little update on this project. Installed 8 egt sensors in the headers and ran it at 15 psi boost 30 deg timing and 1000hp@7300 for a 4 min dyno run and egt's stayed below 1400f. All are very close so this thing seems to be finished. made one pull at max boos but kept the rpm low. 1382hp@6400 32 psi. would have been nice to see the power for bragging rights if we let it rev but didn't want to take any chances.
Nice results. Seems like the fueling is working well. Also, the koenigsegg style exhaust seems to be working great.

Kevin Johnson
HotPass
HotPass
Posts: 7946
Joined: Tue Nov 22, 2005 5:41 am

Re: Need some ideas on what happened

Post by Kevin Johnson » Wed Jun 19, 2019 1:24 pm

jet1 wrote:
Wed Jun 19, 2019 1:06 pm
Well a little update on this project. Installed 8 egt sensors in the headers and ran it at 15 psi boost 30 deg timing and 1000hp@7300 for a 4 min dyno run and egt's stayed below 1400f. All are very close so this thing seems to be finished. made one pull at max boos but kept the rpm low. 1382hp@6400 32 psi. would have been nice to see the power for bragging rights if we let it rev but didn't want to take any chances.
Did you snap a pic of the egt sensor installations on the manifold?

jet1
Pro
Pro
Posts: 441
Joined: Tue May 22, 2012 1:11 pm
Location: Alberta

Re: Need some ideas on what happened

Post by jet1 » Wed Jun 19, 2019 1:30 pm

Kevin Johnson wrote:
Wed Jun 19, 2019 1:24 pm
jet1 wrote:
Wed Jun 19, 2019 1:06 pm
Well a little update on this project. Installed 8 egt sensors in the headers and ran it at 15 psi boost 30 deg timing and 1000hp@7300 for a 4 min dyno run and egt's stayed below 1400f. All are very close so this thing seems to be finished. made one pull at max boos but kept the rpm low. 1382hp@6400 32 psi. would have been nice to see the power for bragging rights if we let it rev but didn't want to take any chances.
Did you snap a pic of the egt sensor installations on the manifold?
No I didn't but i will when it gets here.

In-Tech
Vendor
Posts: 2060
Joined: Wed Apr 21, 2010 4:35 am

Re: Need some ideas on what happened

Post by In-Tech » Wed Jun 19, 2019 2:22 pm

Great job. =D> I'd like to have a peek at the dyno sheets of both the 15psi and 32psi if you don't mind.

Did you ever figure out what killed those exhaust valves in the beginning?
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl

jet1
Pro
Pro
Posts: 441
Joined: Tue May 22, 2012 1:11 pm
Location: Alberta

Re: Need some ideas on what happened

Post by jet1 » Wed Jun 19, 2019 2:42 pm

In-Tech wrote:
Wed Jun 19, 2019 2:22 pm
Great job. =D> I'd like to have a peek at the dyno sheets of both the 15psi and 32psi if you don't mind.

Did you ever figure out what killed those exhaust valves in the beginning?
Dont think a guy will ever see the 32 psi one. It was kind of a whoops apparently.
Wasn't enough water flow through the head. it was short circuiting through the turbo bearing housings.
pulled main caps and rod bearing caps and bearings look like new so one more check on the valve springs and it's off racing for the real punishment

Post Reply