360ci RAISED RUNNER STEELHEAD ENGINE

General engine tech -- Drag Racing to Circle Track

Moderator: Team

racear2865
Guru
Guru
Posts: 1358
Joined: Mon Sep 21, 2009 11:58 pm
Location: tenn

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by racear2865 » Thu Sep 28, 2017 2:51 pm

Perfconn
Is this the RHS head 12801 raised runner 220 cc intake or the Pro top Line 22360022 before sold to RHS. Just interested.
reed

Abbottracingheads
Expert
Expert
Posts: 772
Joined: Fri May 18, 2007 6:46 pm
Location: Crane, Texas
Contact:

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by Abbottracingheads » Thu Sep 28, 2017 3:23 pm

What is the static compression ratio and lobe lift of your cams? Preliminary looks like too tight lsa and short exhaust timing. What are the header sizes and lengths?
Abbott Racing Heads and Engines

perfconn
Member
Member
Posts: 140
Joined: Wed Nov 04, 2009 9:07 am

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by perfconn » Thu Sep 28, 2017 4:26 pm

Racear 2865,
These are the RHS 12801 castings that ended up w/250cc intake runners & 51cc chambers.
Abbottracingheads,
Compression is 14:29 intake lift is .743 minus lash.I posted the flow sheet on heads earlier.The exhaust ports on these heads are in the 70% of intake and don't like as much duration.Anything over 107* LS and they won't pull off the corner.Believe the Dyno headers are 1 3/4 but that's not the problem because it's the same headers we always use.Don't know the length.
I appreciate all you guys help & maybe we can figure it out but I am going to change cams & do another Dyno session.

Tuner
Guru
Guru
Posts: 1890
Joined: Sun Apr 01, 2007 5:26 am

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by Tuner » Thu Sep 28, 2017 5:26 pm

perfconn wrote:Because 34* makes good power with no detonation and 33* didn't change anything.
This only means the fuel is high enough octane to avoid knock, it doesn't answer the question of how little advance the engine needs before it looses power and, "will less timing make more power?"

In the ignition department, what distributor is it and how is it set up, locked or with a curve? Recently, someone I know was told a distributor was locked and was setting timing at 34 deg. @ 3000 RPM, however the distributor still had original MSD out of the box curve wit the big springs and was slowing adding timing up to 5000 or so, totaling at 40. What RPM are you setting the timing and have you checked the timing while the engine is making a pull?
Tuner wrote:
mag2555 wrote:Why the Hell are your air to fuel ratios swinging around by some 20gph at some rpm ?!!!

Man between 7200 and 7400 your going from .23 to over .40, that's huge!
It looks like you have the time between RPM steps mixed up with BSFC. Where am I missing fuel GPH info? I don't see that.

However you're right, the BSFC is erratic. It is anomalous between 6200 and 7200 and particularly it is crazy between 6600 and 6900 where the power backs up 15 HP and recovers. Carbs with too much air bleed do this if they have too large MAB or too large or too many E-Bleeds.
The BSFC wandering around up and down is an indication there could be something about the carb calibration the engine doesn't like. I suppose it could be a header tuning mismatch, but not likely.

I think you should try a different carb and less spark advance before you go to the trouble of changing the cam.
Last edited by Tuner on Thu Sep 28, 2017 5:36 pm, edited 1 time in total.

Abbottracingheads
Expert
Expert
Posts: 772
Joined: Fri May 18, 2007 6:46 pm
Location: Crane, Texas
Contact:

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by Abbottracingheads » Thu Sep 28, 2017 5:35 pm

To pull off of the corner use gear to fix it. With that short stroke it needs rpm to make more power. Make power then gear to the motor.
Abbott Racing Heads and Engines

perfconn
Member
Member
Posts: 140
Joined: Wed Nov 04, 2009 9:07 am

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by perfconn » Thu Sep 28, 2017 5:37 pm

Turner,
It is Crank trigger,so no advance involved.You may be a lot smarter than me but in 40 years of building engines the objective has been to run as much timing as possible without damaging engine.Never ever saw less timing make more power than maximum timing,except w/nitrous.

perfconn
Member
Member
Posts: 140
Joined: Wed Nov 04, 2009 9:07 am

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by perfconn » Thu Sep 28, 2017 5:49 pm

Abbottracingheads,
These are not $100,000 NASCAR engines that you have 2 or 3 spare engines in the trailer.These engines have to log 1000-1200 laps between freshen.There are engine builders that think because it is only 3.27 stroke that it has to turn 9200.I get them in all the time from other builders whose racers are told that.These engines can & do win on a consistent basis turning them 7900-8100.RPM is not a cure all ,making power within a safe rpm is.I am not looking to build a whole new concept of racing,I am just trying to figure why this one engine is down.

sanfordandson
Guru
Guru
Posts: 3052
Joined: Sat May 20, 2006 6:28 pm

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by sanfordandson » Thu Sep 28, 2017 6:06 pm

perfconn wrote:You may be a lot smarter than me but in 40 years of building engines the objective has been to run as much timing as possible without damaging engine.Never ever saw less timing make more power than maximum timing,except w/nitrous.
WTF..... #-o

Tuner
Guru
Guru
Posts: 1890
Joined: Sun Apr 01, 2007 5:26 am

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by Tuner » Thu Sep 28, 2017 6:14 pm

sanfordandson wrote:
perfconn wrote:You may be a lot smarter than me but in 40 years of building engines the objective has been to run as much timing as possible without damaging engine.Never ever saw less timing make more power than maximum timing,except w/nitrous.
WTF..... #-o
=D> LOL Exactly #-o
perfconn wrote:Turner,
It is Crank trigger,so no advance involved.You may be a lot smarter than me but in 40 years of building engines the objective has been to run as much timing as possible without damaging engine.Never ever saw less timing make more power than maximum timing,except w/nitrous.
I can't say who's smart and who ain't, but the way to do it is find the least timing possible that makes the best power. More timing only puts more heat and pressure on the compression stroke. Less timing shifts the heat and pressure from the compression stroke to the power stroke and (more important) reduces the total time of peak heat. So, if more timing makes the same power as less timing, why make the engine suffer more heat and pressure if less timing will make the same power?

You need to find the least spark advance that makes best power. (and try a different carb)

User avatar
MadBill
Guru
Guru
Posts: 12624
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by MadBill » Thu Sep 28, 2017 8:20 pm

Wikipedia and some other internet references notwithstanding, O.E.M.s spend a lot of time mapping out MBT during engine development and define it as Minimum spark for Best Torque...
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.

racear2865
Guru
Guru
Posts: 1358
Joined: Mon Sep 21, 2009 11:58 pm
Location: tenn

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by racear2865 » Thu Sep 28, 2017 8:30 pm

perfconn wrote:Racear 2865,
These are the RHS 12801 castings that ended up w/250cc intake runners & 51cc chambers.
Abbottracingheads,
Compression is 14:29 intake lift is .743 minus lash.I posted the flow sheet on heads earlier.The exhaust ports on these heads are in the 70% of intake and don't like as much duration.Anything over 107* LS and they won't pull off the corner.Believe the Dyno headers are 1 3/4 but that's not the problem because it's the same headers we always use.Don't know the length.
I appreciate all you guys help & maybe we can figure it out but I am going to change cams & do another Dyno session.

Perfconn
I have a couple sets of these left. Do they still cast these and what intake are you using as they are hard to come by also.
reed

perfconn
Member
Member
Posts: 140
Joined: Wed Nov 04, 2009 9:07 am

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by perfconn » Thu Sep 28, 2017 9:49 pm

Reed,
No RHS doesn't cast them anymore.They sold all their stock.I have used many different intakes over the years.The easiest one to come by is the Edelbrock 2926.The hardest to come by is the Holley 300-41.Holley only made 50 of them and they are a little bigger.I used an Edelbrock 2968 on one engine and have used the GM 1103.I haven't saw much difference in any of them but they were all ported by reputable people.This problem engine that is down about 19hp & torque has an Edelbrock 2926 ported by Wilson.
That's what this whole thread was supposed to be about,this one problem engine,not about whether they have too much timing,too little rpm and various other theories about how to build engines.All my engines have been and still are winning and this one could probably win like it is but I'm not selling an engine that I know is down 20hp.

Tuner
Guru
Guru
Posts: 1890
Joined: Sun Apr 01, 2007 5:26 am

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by Tuner » Fri Sep 29, 2017 11:32 am

perfconn wrote:
Thu Sep 28, 2017 5:37 pm
Turner,
It is Crank trigger,so no advance involved.You may be a lot smarter than me but in 40 years of building engines the objective has been to run as much timing as possible without damaging engine.Never ever saw less timing make more power than maximum timing,except w/nitrous.
The odds are slim but with blind luck and another 40 years you might figure it out.

Good luck. :wink:

Ron E
Guru
Guru
Posts: 1941
Joined: Wed Aug 03, 2005 9:35 pm
Location: nc

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by Ron E » Fri Sep 29, 2017 11:38 am

MadBill wrote:
Thu Sep 28, 2017 8:20 pm
Wikipedia and some other internet references notwithstanding, O.E.M.s spend a lot of time mapping out MBT during engine development and define it as Minimum spark for Best Torque...
Maybe its the wording, or the intended use but, I remember Warren Johnson saying the most power was up against or even slightly into detonation. So, there could be different positions on timing.

Tuner
Guru
Guru
Posts: 1890
Joined: Sun Apr 01, 2007 5:26 am

Re: 360ci RAISED RUNNER STEELHEAD ENGINE

Post by Tuner » Fri Sep 29, 2017 11:57 am

Ron E wrote:
Fri Sep 29, 2017 11:38 am
MadBill wrote:
Thu Sep 28, 2017 8:20 pm
Wikipedia and some other internet references notwithstanding, O.E.M.s spend a lot of time mapping out MBT during engine development and define it as Minimum spark for Best Torque...
Maybe its the wording, or the intended use but, I remember Warren Johnson saying the most power was up against or even slightly into detonation. So, there could be different positions on timing.
This is only the case when the fuel is not high enough octane to allow MBT. In his case he was limited to a spec fuel and designed the engine to squeeze the fuel to its limit. If the fuel were higher octane the timing could be advanced beyond the point where power output is reduced and have no detonation.

Post Reply