B2 Motorsports - Mat Twiehaus 427SBF Build

[blykins]

Byron, just give me a call, even if it's just to catch up.

AC, thanks for the kind words.

[PLDRIVE]

Brent why would U need a Pop off valve in the drivers side valve cover if u are pulling a vacum ( I'm assuming Daileys pump is a multi stage rotor)? How could an overpressure event occur unless oil pump fails?

Mark

[blykins]

It's not really necessary, but since you can control the amount of vacuum that the pump pulls, it's nice to have. If you don't let it pull any, it's essentially like a breather setup.

It was recommended by Peterson.

[scottj]

Originally Posted by PLDRIVE

Brent why would U need a Pop off valve in the drivers side valve cover if u are pulling a vacum ( I'm assuming Daileys pump is a multi stage rotor)? How could an overpressure event occur unless oil pump fails?

Mark

The pop off valve is for a sudden pressurization of the crankcase... such as when you burn a piston. Helps prevent blowing the pan off and making a mess on the track.

[ERA Chas]

OK-I'm gonna show my ass and say, 1.35 HP per CI.
570-575 HP @ 6200
540 LBFT @ 4900. Over 400 from 3200 to 6000.
Promise to post the full sheet of best run including VE, BSFC, AFR and weather conditions??
Anybody else want to play the Dyno Jockey Game??
Any experts know how much that dry sump system eats? I'm guessing maybe 15HP??

[951mat]

I don't want to guess a hp number bc I want to temper my expectations. As far as the hp loss from the pump, I'm no expert, but the man that sold it to said about 4 hp. I have no idea what they usually eat. I would've guessed they added more hp than they eat when running on a decent vacuum.

Mat
(yes I'm scared about tomorrow)

[ERA Chas]

Originally Posted by ERA Chas

OK-I'm gonna show my ass and say, 1.35 HP per CI.
570-575 HP @ 6200
540 LBFT @ 4900.

Hey Brent, why did you reprint my quote as results??
---NO WAIT-I was right on! OK, you out-torqued me a tiny bit...
Well kudos to you-you built the danged thing. And nobody wore shrapnel home from the dyno.
Always a good day.

[ERA Chas]

Ready to feed formula (Brad Penn) and change diaper (Wix, K&N, Moroso)??
You should be good at that by now...

[blykins]

I have definitely seen my share of baby poop here lately.

Yep, ready to light her off tomorrow...

[Jerry Clayton]

just remember that crankcase vacume on a dry sump is like another oil pressure pump---with enough vacume pull, the engine doesn't need a pressure pump!!!!!!!!

[ERA Chas]

I'd run a hard line the length of the chassis so no need for anti-collapse spring. Put unions at each end, short braided stainless connectors to tank and block.

[blykins]

Nobody is as scared as I am. ROFL

Chas, I think you're in the ballpark on the horsepower/peaks.

As for the dry sump stuff, I would venture to say that the power it takes to drive a pump shaft and regular oil pump is probably about the same as the power it takes to drive an external pump.

However, as Mat said, the vacuum part of the pump will help things. I'm not going to pull a great deal of vacuum on it, there's really no reason to. I'd rather pull 8-12 on it instead of risk pulling the oil off the wrist pins.....

[vector1]

-16 will be fine, i ran a late model with the tank in the back and that is what was used. you can use this hard line for the scavenge and supply lines and do away with the traditional cooler in front of the radiator.

https://lefthanderchassis.com/v2a/vi...dgroup=2511674

if you use soft line that will work also, will not collapse. aeroquip starlite is some pretty nice stuff and it looks like speedway has it on sale right now. still kind of expensive but i couldn't find the guy i used to buy it from, must be out of business.

Aeroquip Starlite Hose, -16 AN - Speedway Motors, America's Oldest Speed Shop

on second thought i am pretty sure it was -16 line that was used front to back, could have been -20, has been while and it was pretty big stuff. but we did run the hard line on the return and supply.

[PLDRIVE]

Thanks Brent & Scottj
Scottj thats a good point (protecting the track). I did not think in that respect.

Mat what Did Peterson tell u I ran -16 from Tank to Union, then -12 to pump (short run). -16 from pump to union, then -16 to Tank . as Recommended by Patterson and Aviaid.


Mark

[951mat]

The Peterson sales guy just said they didn't like the inner support springs because of the restriction they cause. I like the hard line idea (but not the costs of all the extra fittings....


Mat

[Clois Harlan]

I have gone back and looked at all the parts and effort put into this build and I am comfortable guessing maybe 750 fwhp. Given that much power Mario Andretti should be worried should he happen to show up at a Run N Gun event!

[ERA Chas]

Mat-you'll read this after the dyno but here's a thought.
Mount the tank in the passenger footwell, maybe with some chassis tubes around it and sheet metal protection around it. Eliminates the long line runs...

[AL427SBF]

Dyno day, very interested to see what the numbers come in at. Too lazy to look, but has Brent posted the the compression ratio? Guessing for pump gas no more than 10.5:1?

[Jerry Clayton]

Brent---you don't have much control over the amount of vacume you will pull with this set up---it will pump so much according to the pump sizes and speed(rpm/belt drive ratio)that you choose and be countered by amount of leakdown /blowby and volume the pressure pump puts back into the crankcase----your relief valve ??????????will hopefully prevent the loss of intake gaskets with the push/pull/push pulses in the ports

[blykins]

Originally Posted by Jerry Clayton

Brent---you don't have much control over the amount of vacume you will pull with this set up---it will pump so much according to the pump sizes and speed(rpm/belt drive ratio)that you choose and be countered by amount of leakdown /blowby and volume the pressure pump puts back into the crankcase----your relief valve ??????????will hopefully prevent the loss of intake gaskets with the push/pull/push pulses in the ports

Jerry, you nailed it buddy. We were pulling about 3-4 inches of vacuum today without any change when we were playing with the regulator. I used a teflon rear main seal and tried to seal the engine up as best as I could on the other gaskets. I honestly just don't think the dry sump pump was big enough to pull the big amounts of vacuum.

It's kinda hard for a street engine that will be raced part of the time. Of course the vac part of the pump probably could have been more worthwhile with some pretty low tension rings, but I really didn't wanna go there if Mat's going to be driving it on the street a lot of the time. This engine is a balance of street car/race car. Sometimes it's hard to draw lines.

Well, for the results...

573hp @ 6400, 562 lb-ft @ 4800.

It ran very well. No issues, no leaks, just a good strong engine. I think the horsepower peak is a testament to the cylinder heads as the cam is just 240° @ .050".

AL427SBF, the compression ratio was around 10.3:1. I can routinely get away with about 11:1 SCR around here with 93 octane, but when I send engines out, I want to be sure that they will run on the gas that's available where the customer is. A lot of cities only have 91 octane, etc.

This thing needed about 10 more degrees duration on a solid roller cam and it would have been real fun.

I'll post the dyno sheet later on. I got back, trying to beat the rain, then cleaned the engine for Mat and taped everything up. I'm pooped. I also had a customer who was rear wheel dyno'ing a 408 LS2 engine this morning. Needless to say, my nerves are shot....hahaha That one made 501hp at the tires @ 6000 rpm. Not too shabby.