Discussion in 'Tomahawk Block Buildups' started by slimfromnz, Feb 26, 2013.
I better get to work so I can buy parts for mine.
Royden, congrat's on those numbers! Nice job.
I'm still TOTALLY not convinced that the oil pickup screen (if you can call it a screen) will be OK. I think you are going to have cavitation and oil issues at some point. You should have unrestricted oil flow to the pump at all times. Let the pump do it's job and restrict it after the pump.... never on the inlet side. I've worked a lot with Peterson Fluid Systems in the past and they taught me a lot about oil flow and pumping oil.
Again good job but please reconsider modifying that pickup.
Just my .02
Ya, after looking at the videos, I agree that while what's going on there I am sure is much better than before, does look like you still have an issue.
Typically they are supply side things.. volume related sizing.. Pickup tube, block passages ect.
It can be the pump's ability to move oil, or restriction in the passages after the pump..
I would say with 3 gallons of oil in the sump, even if we still have less than perfect drainback, that volume of oil will keep the pickup submerged in a dyno run, so we can rule that out..
Yours is the best I have seen so far, as far as maintaining pressure, I would like to see the actual number up about 20psi from where it is, but it seems that these motors have lived with this type of pressure.
Also a little concerned with the nose-dive in the last couple hundred rpm.. just a slow decline, or is if falling off the cliff?
Your working on the same equipment I am up here (Superflow 902) with the same software.
Go back and see your guys, they should be able to give you the digital files of the pulls... and a read-only copy of the superflow monitor program, that will allow you to work with the data.
This will really help you analyze your data now.
You can look at the sheet numbers, but also graph and overlay runs, with all the different channels available.
Thanks for your support guys.
Steve, I am going to wait and see what Jim does as far as a bigger pickup tube goes.
Jim it does drop to 58lbs @6500, but thats where we stopped the run. I will ask Bill if he can give me a copy of the Superflow program read-only and all of my runs.
It was great to see it run nice on the dyno and give me the figures Mike told me it would. Bill said the motor could do with some more intake plenum......... I told him I am more than happy with 832hp for the street. He also said this motor has very impressive low end power figures
Go easy on the Java guys :laugh:
In this video http://www.youtube.com/watch?v=wu_niEsxEsg It is so hard to see the screen but I watched it over and over again and to me it looks like the O/P only drops at the end of the pull with the RPM drop. It would be nice to see a bigger tube and P/U but when I watched your video's from your last time at the dyno and the oil pressure is all over the map which it is not doing now so I would say you fixed that problem. I must have missed it but what oil are you using? IMO As far as OP goes with priority Main oiling 60 psi at 6000 to 6500 is not a problem. It will be good to see the pulls on paper, that would take the guess work out of it. I think we get all nervous from working on our old non priority systems. I have seen less OP in other brands make more power @ higher RPM's with out any concerns. That all said I am exhausted today and might be missing something.
Did it fall on its face after 6100 power wise?
Also, I might be heading to Australia this up coming year so consider your self warned!
I am sure you will be fine. Good job, and it's the next step in evolution of these. Documentation is great to have.
That would be awesome to meet you. Consider accommodation taken care of!
I spoke to Mike T this morning to share my news, and he was happy with the op that low because it's a true op at the mains and not like the iron block.
Mike said he thinks it's number 7 to get running and he thinks I am going to "crap my pants" when I get to drive it
As far as the power curve, it did drop away but that was the end of the run I think. We only ran it up to 6500.
Here is the only dyno sheet I could get coz Bill's printer ran out of ink
Not very clear but it's a nice progressive curve
Got it done though. Fark, I pity someone who wants to steal the motor and box
It was a bloody mission, but it's done.
Looks Good Royden:
Funny to look out the garage door there and see the flowers blooming in Mid November.. like you live on the underside of the planet..
Oh wait.. you do.. you got this done just in time for summer!
Have fun with it!
Good dyno sheet.. what are you cam specs again? @.050 duration?.. and your head flow numbers, if you have them. Working on making one of these make power to 7000, could use the reference point from yours.
Are you going to put the vacume pump back on?
I will have fun Jim, neighbours probably wont. We have been in this place for just on 4 weeks, and the neighbours all seem very friendly and most of the guys want to come for a ride when I get it running. Whats the bet they will just want to watch once they hear it LOL!
@.050 254.5' I and 265' E
Here is the flow sheet
If I had more plenum/carb and bigger primaries, only running 2", we think it would kept making power to 7000. But I like it where it is. I dont have to push it hard to get the power
I am probably not going to run the vacuum pump at this stage, not until I drive the car to get a feel for the brake pedal, and then make a descision. I did however buy a TA's smaller crank pulley just in case.
I agree, your power range is just fine for a street driven deal.
Good to see that pwr from a 555 with a relatively mild cam, and good heads.
Probably don't do the justice these heads need. But there is room for improvement if required
Had to utilize the heater and bypass ports on the water pump. I basically cut the barb fittings off, drilled them out and taped them for 1/2" NPT. I jammed a vacuum cleaner up the water pump inlet to catch all the swarf
The boss below the barb fitting you cut off is there for exactly what you used it for. That's why I made that portion larger. Glad to see a thought put to use. Nice job Royden
Its a nice casting to drill and tap. No "picking up" of the swarf as I was taping the hole. When you machine or work alloy, you know when you have a crap casting
Did you get a chance to go over the dyno data I sent you?
That is one beautiful engine, I was wondering if anyone has attempted to make a belt drive Timing set yet? I do know it is possible but hard to do.
I think there are a few custom made ones out there.
Since it's not a Buick car I thought I would post these pics in my engine thread
Just had the glass cut and installed. All I need is my driveshaft then I can drive it for the first time :3gears:
I've got 4 weeks till our powercruise event where I can have a go at this
I think I have the power right, just don't know how the car will react