First Bench - Continued from old forum

Discussion on general flowbench design
TiredGXP
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Joined: Thu Mar 04, 2010 9:13 pm

First Bench - Continued from old forum

Post by TiredGXP »

Continued from:
http://www.tractorsport.com/cgi-bin/for ... ;f=1;t=503

Still haven't committed to a bench design, other than to rule out an "orifice in a tube" design. In the mean time, I played around with the flowcalc spreadsheet that stef-1 posted on the old forum and changed the math around to work with a pitot bench, so no need to worry too much about the math converting manometer/weather station readings to airflow in either an orifice or pitot bench.

Right now I've been looking for some Domel 4963447 motors. Prices on the web don't seem too bad, but shipping is ridiculous, so we'll see what some of the local central vac suppliers want for motors.

project:
Now thinking about dusting the heads I have and going with aluminum heads from a 3100/3400 gen 3 60*V6. I figure I'd be starting with a set of heads that flow more stock than I'd ever get out of the stock iron heads.

No real rush to make a decision though. I'll get the bench built first and work over both sets of iron heads to see what I can learn about porting and flowbech operations before working on a some gen 3 heads.

Cheers

Al
Forced_Firebird
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Re: First Bench - Continued from old forum

Post by Forced_Firebird »

Hey Al,

Nice thing about the two sets of heads is that the same adapter will work for both ;) You will soon see that you will have to spend several hours to achieve the aluminum heads stock flow, and you have those ugly chambers and really poor manifolds to deal with. If you are keeping the car naturally aspirated and have some fabrication skills, the iron heads can use the lower manifold for individual TB/carbs, but even the local Midget cars are using the aluminum heads as a base.

If you are willing, I would like to compare numbers as I believe my bench is not agreeing with others'. My numbers are consistently lower when I flow stock heads and wonder if that's also the reason my ported heads don't flow as well as theirs.

-John
"Light travels faster than sound; that's why someone might look bright until they speak." Quote from Pocket-Rocket

-Johnny
TiredGXP
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Re: First Bench - Continued from old forum

Post by TiredGXP »

John:

Yeah, no problem sharing data on flow numbers. Whether I end up with an orifice or pitot bench, I'll get some plates from Bruce to calibrate the bench with. It would be interesting to see what kind of numbers someone else gets for a set of stock iron 2.8/3.4 heads.

Speaking of which, I have one set that are untouched, and another set where I've gasket matched the intake, opened up the valve throat to ~.88 the area of the valves (still need some work to be consistent from port to port) and generally just cleaned up the bowls on. I can't believe how small the valve throat was on these heads.

The engine will be boosted - I have a nice little T3/T04E snail waiting to go on. I'm not interested in using the stock upper and middle Fiero intake manifolds, so I've been doing a fair bit of research on intake runner design over the winter. Based on what I've found, the 3.2 I'm building needs intake runners of about 18" length (including head) and a minimum 1.47 sq in CSA. I was able to open up the lower intake manifold to this minimum CSA, and have a lot of metal left If I need to go larger. The upper intake will be built out of stainless plate and tubing - need about 10.5" more length for the intake runners, and looking at a plenum volume of 5 liters. Just need to find some inexpensive 1.75" trumpets for the runners.

As I mentioned in a previous post, I'm now a bit torn between staying with these heads and running higher boost, or going with more modern heads, high compression and less boost. FWIW, Desktop Dyno tells me that I can get get to my initial power goal with custom intake, iron heads, 12 lbs boost and 8.5:1 compression, or with the gen 3 intake + heads, 8 lbs of boost and 10:1 compression.

Cheers

Al
Brucepts
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Re: First Bench - Continued from old forum

Post by Brucepts »

Interesting all the V6-60 guys here!

I'm just getting started with mine but need to make up my bore adapter/head stand first and I'm dragging my feet. My problem is I need to use my flowbench for testing flowbench parts so I have to tear it down all the time. I'm currently getting a second flowbench built so I can have one for "playing" and one for work.

I did flow a Fiero throttle body and wonder why everyone is so keen on bolting on something larger? This TB flows way more than the intake can handle. I'm going to stick with the stock intake as I want mine to look stock I've decided and the aftermarket intakes look . . . well they just are (cant find the right word) . . . for what they charge.

I have a set of unmolested stock Fiero heads and I'm searching for a 3.4L block to go with them once I'm happy with my flow numbers. Doubt that will ever happen, my goal is to just "play" and not really build an all out high rpm screamer like most of the other Fiero guys are doing in their quest for 200hp.
Bruce

Who . . . me? I stayed at a Holiday in Express . . .
TiredGXP
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Re: First Bench - Continued from old forum

Post by TiredGXP »

Brucepts wrote: I did flow a Fiero throttle body and wonder why everyone is so keen on bolting on something larger? This TB flows way more than the intake can handle. I'm going to stick with the stock intake as I want mine to look stock I've decided and the aftermarket intakes look . . . well they just are (cant find the right word) . . . for what they charge.
Fugly? :mrgreen: .

Just for my own benefit, I'll probably flow the stock Fiero intake, just to have a comparison to the abonimation I'll be building. Be interesting to see what happens to flow through the head as you add each piece of the stock intake manifold system.

Cheers

Al
Forced_Firebird
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Re: First Bench - Continued from old forum

Post by Forced_Firebird »

Well, that "other" intake actually lost quarter times with a guy I know. They are horrible.

Had I known there was so much interest in the 660, I might have been inclined to speak up here long ago haha (was a member at the old forum since '08).

Bruce, the manifolds are the restriction in the iron heads, yes, but the gen3 stuff, it is the TB since that same one is used on the early aluminum heads. Latter 3400's got the 56mm and the 3500 got 65mm.

The adapters I build for my friend were for the 60*, one matches the 3500 bore, the other matches the 3900 bore. The 3900 had the center-line of the piston bores across the banks moved below the center of the crank and changed the location of the bore in relation of the head mounting bolts. This was quite a task to measure and machine, the 3500 wasn't bad since they shared both the same bolt pattern as well as bore center as the gen1's, the bore was just larger than the 3400 or iron heads.

He found some clear acrylic tubing on Mcmaster that is actually 1/2 way between the 3400/3.4 and 3500 bore and made the adapters I posted on SpeedTalk and the old site here...

http://s158.photobucket.com/albums/t87/ ... 0Benchtop/

Al,
As far as your car build is concerned, I have turbo'd a 3400/3500 in a FWD Corsica. Ben at WOT ported the heads and he had the 65mm billet TB, head studs and Felpro gaskets (approx 9.1:1) - he ran a best of 12.9, 113mph, 1.98 60' (not all at the same time haha). He seen a few spikes over 20psi during some minor problems with the reference lines blowing off, and even forgetting to connect one once and the thing is still running. Third or fourth transmission (3t40), the original one blew up the day after the install.

Funny, I have a 70k mile Fiero motor in my shop, and has been sitting for a few years. My friend put a 350hp crate 327 in his 88GT and asked if I might be able to sell or do something with the engine, went to turn it over the other day and it's seized. So, including the heads on that, I have 3 sets of iron heads, all unmolested, one set I am using for a core for the jobber coming up.



Definitely let's exchange info, and I am just waiting to have the extra cash to purchase the calibration plates to see where I am at with the FlowQuik, but it's working great for comparative testing and is nice since if I shut off any of the 3 vacs, the depression will go down, but the flow rate remains unchanged. I bought it when I opened my small shop in October and wish I would have held off, but hindsight is always 20/20. It was quick and easy to setup, but I guess until I take advantage of the swirl meter etc, not sure if it was the best decision - trying to purchase a flow bench, an auto lift, and put deposit etc on a warehouse with a few $k wasn't easy.

-John
"Light travels faster than sound; that's why someone might look bright until they speak." Quote from Pocket-Rocket

-Johnny
TiredGXP
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Re: First Bench - Continued from old forum

Post by TiredGXP »

Ah, yes - cash.

The sale of our acreage will be complete in a couple of weeks, so that should free up some cash for toys and tools again. I've been missing the 38x30 garage space - most of my woodworking equipment is in storage because of space limitations in the new garage - I'll need a very compact bench!

Unfortunately, the set of Gen 2 heads and intakes I had went out in a dumpster as we were getting rid of all the renovation waste. Now I wish I'd kept that stuff to play around with.

Cheers

Al
TiredGXP
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Re: First Bench - Continued from old forum

Post by TiredGXP »

Picked up some tubing and misc bits to start building manometers...

And I ordered the PTS flowbench plans from Bruce yesterday.... So Bruce, how do I get access to the PTS flowbench part of the forum?

Cheers

Al
TiredGXP
Posts: 12
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Re: First Bench - Continued from old forum

Post by TiredGXP »

Bruce's plans came in the mail yesterday. Gotta love government efficiency - the post office had the package for 2 weeks...

Maybe by late June I'll have time to work on this.

Cheers
Brucepts
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Re: First Bench - Continued from old forum

Post by Brucepts »

I really wish I could just email them out, problem is once a few sets are out there they would spread like "wildfire" and my income would drop like a rock. Since the forum is free the plan's sales helps to keep it ad and fee free.
Bruce

Who . . . me? I stayed at a Holiday in Express . . .
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