Inliners International Forums General Discussion Hi Performance Dyno day for a 250

I removed my post as well, as per Tom's request.

Now lets all move on back to the discussion at hand.

Just curious Hank, did you personally ever deal with Leelites?

Ok
First off I said I was done here as to posting. Now I am going to
OPEN my Mouth once again. So first off I never called Lee secondly I listen to what He was saying I never said Much of anything. THEN I see His Normal BS on Ebay Saying I said this ot that which to is BS The Guy always talks in circles Or changes the questions around when he is asked one. and still ONE never gets the answer they asked and That I still see. If I or others are doing things so wrong.Then what the H*ll is the problem giveing the right answer/s when asked. So to me Personal Oppion here it's still the sameOle bag Of crap.
He takes what anyone has to say and turns it around an then out comes the BS.

And Scott so as to him speaking to me (and has even spoken to Larry several times in the last few weeks,) That is a Load of BS
I maybe spoke with him once in the past MO.ANd I let him do all the talking i never said much of anything.
So take what ever you want to hear they way you think it is.I know not everyone is in or was in the Lime light of things like sone think they may have been.
Now you all have a Great day and Injoy your chats.

PS if anyone wishs or see this as a Bashing Then so be it. It's the way you maybe reading it.
It's MY 2cent an once agian I'm done.

No, I choose not to get a headache, but my friend has &,,,,,,,,, coo-coo.

So, Tom, I heard a while back that you were planning on doing some dyno tests on a 250. Is that still going on? Are you looking for donations? It's hard to find much about it here. Beater

Yep, the tests will be going on. This weather has slowed me down. Had to clear my shop to get the F450 4X4 flatbed in there. Talk about leaving the freezer door open. That truck has a winters worth of ice and snow stuck to it, and winter is only about 2 weeks old! It took over 24 hrs to thaw it out. Now to change the fuel pump.

Next the 250 will go in the shop and be dismembered for rebuild. Only the one divided head to work on also. The rest of the parts are still ready from the 292 dyno tests.

Contributions are coming in. Got one from SOB, Bill Mulholland from down in Texas, sounds like they are also getting a taste of winter (not liking it much either).

If anyone is interested in helping, here is the wish list.
Possibly 3 cams from Compcams
3 cam timing gears from cloyes
funds to help pay for dyno time

If anyone wants contribute funds, here are the 2 ways

Paypal to tom@12bolt.com
(send it as a gift and they don't seem to take out fees)

or by mail

Tom Lowe
3063 200th st
Dysart, Iowa 52224

Telephone 319 476 2172 evenings 6-10 pm

Anyone who contributes get the data collected from the tests. For the 292 dyno tests, over 50 contributors helped make it happen. Some from far away in other countries. Contributors are also kept confidential. I do have a 250 dyno list of contributors started. Thanks again to those who have allready.

Now out to change that fuel pump. Tom


Fuel pump is done now, fuel at 50 psi really helps make that diesel roar.

Tom -
Just wondering how your magazine article was progressing. Will it run before the 250 tests or will you wait until after they are done?

Bob

I'm going to call Al Gore and find out where all that Global Warming is going on and move there. It snowed here a week or so before Christmas and I got stuck on my way home from work New Years Eve. My first act of the new year was to walk back down with a set of chains and a shovel New Years morning and get the Yukon, 1/4 mile from home. The snow is mostly off the road today but we are getting more tomorrow. I've just got to get the dozer fixed and cut more wood in the summer. Sorry to whine I'm sure efi-diy is really cold. I'll send $$$. Beater

Bob,
The article is going good, most of that is in Scott's hands now. He is a much better writer than I.

Doubt it will be in a mag before Dynoing the 250. From reading articles in many mags, they seem to be about 3-4 months slow. Tom

Tom,
What size & brand side draft carbs are you going to use?

Do you have any 194 heads flow tested w/a 1.85 -1.90" range intake valves installed?

Would it be possible to test a cyl head w/these size valves for the dyno runs & have the head milled a bit more (than the previous 194 head) for more compression?

MBHD

Do not know the brand, they are just not a familiar carb to me. Believe they are 45 mm.

As far as the 194 head. Not going to build any with small valves. The 1.84 valve in that head will not flow as well as a 1.84 in a open chamber head. Will rerun the one run on the 292. May open the chambers some. To match a open chamber heads clearance, might as well started with a open chamber head.

I personally think there is more power to be had with different techniques than a "194" head. Which has also been proven to me with flow tests and dyno.

Still open to someone supplying a prepped "194"head. Tom

The 250 is definately started now. The boy and I tore down the donor 250 today and took it in to be hot tanked. Next the machine work will start. The motor was a 76' 250 with a 1bbl integrated head. The head is in the iron pile now. It had to be as heavy as the block!

Recieved the 3 weber side draft on Friday. Carbs are also coming.

A few more contributions have came in and thankyou's to you guy's.

Taking pictures as we go on the teardown and build. Tom

Tom are we looking at Feb. or March for the next tests?? If we wait too long will the dyno costs go up?

Jalopy,
Not sure on a date yet. Just yesterday( Fri) the block was hot tanked and magnafluxed. That all looks good. Preliminary checks indicate a .040 overbore. Block will be decked and bored next week, then order the pistons. Crank will need to be turned and balanced. The dyno has a Pontiac on it now. The operator was teasing me and said when running the Pontiac, the dyno popped up a message stating to test only 1 inline 6 at a time as the torq reading was too high. The Pont is a big cube sucker and was pegging the tq beyond the 500 ft pd mark closer to 600 ft pnds.

The lower end should go together relatively fast. The top end stuff is still ready from the 292 tests. Still aiming for later feb. Anyone interested in coming here to help? I know my local club will. Maybe some of you guy's could come too. Tom

Pistons ordered today, block did bore to .040. Deck height measured 9.135 so ordered pistons for a zero deck and pure flat tops. Crank was deburred and going into the grinder on Fri. Tom

Tom, Exactly where is the measurement taken for the deck height? Crank pin center at TDC to top of deck? Beater

Recieved the OER/Weber carbs and extra parts from 1/2 way around the world! He also sent a new side draft intake. Now that is stepping up to help out with the 250 dyno tests. Will be interesting to see how it runs with this setup compared to the normal parts.
Pistons should be here in a 1 1/2 weeks. Tom

You are going to ask yourself,why didn't I buy & run side drafts years ago,instead of this dumb 4 barrel carb & intake manifold.

It will impress you if there jetted correctly.

As always,how bout some pics?


MBHD

One reason not to run the weber type carbs. No choke. Would not work well in my climate. He sent the carbs with 40mm chokes? (venturis). Also 36mm and 32mm.


Got the crank back. It is turned .010/.010. I deburred it before taking it in, oil holes are all chamfered now. Really looks nice!
Cam, rod and main bearings are all ordered. Crank is getting balanced next. Got the new oil pump, will disassemble and deburr it.

Block work includes:
Plugging the oil bypass (like full oil filtration all the time), plug the front timing gear oil spout.
Deburr the internal block.
Chamfer the cylinders near the intake/ exh valves ( better flow).

Get a couple more cams ready with timing gears.

When pistons get here, get rods/ pistons balanced up.

Winter is going fast if I keep this up. Tom

Some Webers have a cold start circuit (choke), others don't, it is very easy to flood the engine and wet plugs using the cold start mechanism, as it very crude in operation. The accepted technique for cold starting is as follows:-

Allow the float chambers to fill if you have an electric pump, this should take about 5-10 seconds, fully depress the accelerator rapidly four times, then on a light throttle, turn the engine over, if it does not start immediately, repeat the procedure three times. The engine should fire, but may need 'nursing' for a minute or two before it will idle, gentle prodding of the accelerator should keep it alive long enough for it to warm up. If the engine does not fire within three attempts, then try five or six pumps. If this does not work, depress the accelerator fully and hold it open while turning the engine over for 5 to 15 seconds, then close the accelerator and try again.

A different guys quote:
And cold starts are no problem since they have an accellerator pump and a cold start ... My Alfa with webers started easily in zero deg weather. ... That aside, a properly tuned IR set-up using Weber DCOE, IDA, ...

On difficult to start engines with carburetors, waiting 20 to 30 seconds after pumping the accelerator pedal several times before starting also helps. This allows some time for the gasoline to evaporate in the manifold. This technique works well on the second or third try if necessary, but does require patience.

I'll ask my friend Steve how he got his truck started to get to our chapter meeting tomorrow. He's bee running 3 Webbers for many years. Beater

This is where I came in.

Enough about the choke. This engine will start just fine in a controlled dyno cell enviroment.

More interested in power output. Tom

Tom, I thought my 68 250 block already was full flow filterd! also why the timing gear oil blockoff. Herb 3241

Herb,
These series of engines are full flow filtered. But at startup, with thick oil viscousity, there is a bypass that can and will open. This will allow unfiltered oil to bypass the filter. GM put this in so that when dummy's did not change their oil and the filter became plugged, the motor would still have oil pressure.

I plug the front oil spout to keep more oil for the crank/ rods. Later Gm engines did not use this feature. Plenty of oil flying around down there. Tom

I see that Leo's book states that for street use,, eliminating the oil director to the gears is fine.

But,,what about for race/street double duty cars?

Anyone?


MBHD

We always removed and plugged all of ours, as does most everyone that I know that raced/races these engines, there is so much oil slash and spray inside the engine,especially from behind the front main and front cam bearing journal the timing gears will get plenty of oil on them.

MBHD,
I keep the oil director to lube the gears, on a turbo car the pressure of opening the exhaust valve is very great because of the extreme cylinder pressure, therefore the force between the crank gear and cam gear is greater, I don't have any problem with a lack of oil pressure or volume with a HV/HP oil pump.

Just my thoughts,

Harry

Sent a email out to all contributors. It is the schedule of tests to be run. If anyone was missed please contact me.

There is one recieved over the weekend not added to the list. Will be this evening.

Got a bunch of test scheduled. Have atleast 7 cams to choose from and 4 different head configurations. Testing a divided port and maybe will even turbo it! Blow thru down and dirty. Tom

Any requests?

Had a present sitting on the porch today! 6 shiny forged pistons all wrapped up pretty. Looks like I have some work to get done now. Tom

Pics would be nice. Hint ,hint.
What are they flat tops?
No valve reliefs?
Dished?

MBHD

I didn't get schedule, will be in Iowa today and one day next week,

Just got back from the shop. Block is now deburred and the cylinders are chamfered. Then worked on some heads.
Block will get honed next with a tq plate and head studs. then cleaned again for final assy.

Jalopy,
I sent the email out the same as with the 292 tests. Checked and you are on the list. Will send out again. Subject of email will be 250 dyno day.

Hank, Took plenty of pic's, wife went to a program and took the camera. Will get some posted later. Tom

Here are some pics of parts and some cylinder reliefs. Tom

The line is top ring travel, or with safety margin of X" added?
Is the width a function of head diameter?

Please ask questions in layman terms.

The top ring land is down .300 and the chamfers go down .150. Should be no ring sealing problems. If you look at the way the valves are located offcenter of the cylinder, these chamfers will remove the sharp 90 degree edge the airflow hits leaving the intake valve. Tom

I'm used to relieving a flathead cylinder (different purpose, obviously), but we normally stopped the relief depth at 1/16" minimum above the highest point of top ring travel, to prevent the ring from getting too hot. They don't appear to suffer any damage from passing right into the relief, provided it's not too wide. If you have to do this, be sure to make a small radius at the edge to help the ring jump in and out (like a 2-stroke exhaust port).
A common recco for valve relief used to be a minimum of .100" larger radius than the valve head.
Depth to whatever is indicated (1/32" is pointless - but it makes you feel better! some engines will take 3/16" deep.
Shape: by moving the 2 cardboard circles (bore, and valve @ OD + .200") away from each other until the crescent of overlap is the relief depth; this determines how far along the wall the cut extends. It's going to look like yours, but easier to duplicate in all cylinders.

What I've never seen done or discussed: without making the relief depth greater, is making a roll-over radius at the top (using as much of the gasket surface as possible) to start the relief helpful?