Inliners International Forums General Discussion Hi Performance Dyno day for a 292, Need help

Tom thanks for letting us Q.C. boys participate on the dyno runs!!!!!!It was great working with everyone.Anyone who wasn't there I'll tell you this was a monumental undertaking,this was a well thought out process.The amount of cams,heads and intakes was impressive!Even though it it seemed like kaos some times everything was well organised.The dyno owner even had a sense of humor,putting "no more inlines" signs all over.It was a great day sun and we all had a great time and learned a lot.Thanks again!

Unless you have a loose converter that stalls to 2500 +,,, your clifford intake will not out torque the offy down low,,, especially if you are running a 250 ci engine or smaller,,,,big difference between the two intakes for a street 250 engine.

I know first hand about the two intakes,,,the offy is better suited for a street engine w/low stall converter.

As Tom stated,,2500 & above the clifford made more torque,,,most street dirving is not above 2500 RPM,,unless you have a hot set-up.

The clifford intake ,,from idle to 2500 is really weak....

Two cents thrown. IMO

MBHD

There are other ways around getting more torque from the Clifford,,,

Remember the 292 has a stroke of 4.120",,the 250 is 3.53" big difference!!

Hank,
I said nothing of the 250 motor, this whole test was about a 292.
The Clifford was the hands down winner for tq over the Offy. With the test ran and parts used (street oriented ) it had the Offy by 10 ft lbs most of the run and sometimes more. The dyno testing was set at a lower point than would be for a V8, ussually pulls do not start at 2500 RPM.
Most people do try to design their engine to have the most tq for acceleration, the RPM range for that on a 292 is typically 2000 - 4500. These tests prove it and we did it with multiple tries.

Maybe next time we can try dynoing a 250. Would you be in?


Got the replacement trial distributor lined up, will get it mounted and hit the 292 for some more info, won't get it all done till later this week. Have to catch up on Daddy stuff.

i'm confused.. are we going to see the results on here or are you going to wait untill the next dyno day? either way.. i know it took a lot of planning and hard work so i just wanted to throw my "attaboy" in there.

WOW, that's alot of work.

Good to hear of solid data for the most part so far.

Hope the "bug" doesn't turn out to be more dificult than you currently believe.

Heal up fast.

If you decide to do this again with a 250, count me in, maybe do the Edelbrock vs Holley vs multi-carb?

Justwynn,
I will be posting more results, really need to clean up all the data collected so far. Also did not get finished with all the planned dyno tests. Hopefully late this week or weekend for that.

Also anyone who sent me contributions is going to get way more info than will be posted here. It is only fair as they really did HELP even though they are not here.

A email was sent out last night to all contributors, if you were missed let me know the correct name and email to send to. My email is tom@12bolt.com .

Sean,
You guy's were a great help and very eager to get things done. Just wished the engine would have cooperated more. Wished you would have cleaned up the beans! Bob, the shop owner enjoyed talking to all of you also.

Jalopy,
I am not against doing a 250 the same way and will certainly consider it. Do not have a short block together to test. Now would be the perfect time. The heads, cams and intakes are all lined up and ready. As are all the correct tools, exhaust, ect.

The OFFY VS Clifford test would be interesting. As would the rest of the same tests used on the 292.

Who has one they want to flog? Bring it on. Tom

Tom, A 250 test sounds like a good idea. It would really be something to see the same guys, in the same place, with the same parts, do the same tests. I'll rob another connivence store. I wish my Megasquirt was done. It would be fun to throw a TBI into the mix. Almost as easy as a carb change once the sensors are in place. I bet we can find the money if you've got the time. You know there's a 250 short block out there. Beater

Tom,

I'm glad things went well (for the most part). My dad has been asking all weekend how it went and if there were any outstanding results.

I'm wondering if a multi-carb setup would provide any beneits as far as fuel distribution? Or if it'd just be more show than go in the end.

And aside from that, I eagerly await the test results, and definitley let us know if you need some more funding for another day at the dyno.

Also, you have mail.

-Sam.

How about a stout 230 short block? Steel crank, 5.7 Crower rods, and TRW forged flat tops in a .030 block. I'm willing to provide the short block for dyno duty.

With some pistons (Tom???) I could put together a 250 as well.

With those type of goodies in it, I think I see the opportunity for doing some turbo testing possibly.......

Tom:

Outstanding job (with more to do?)!

It's the time of year for us to pay property taxes, various (annual) insurance premiums, and a bunch of other things. Since I'm in check writting mode, I'd sure like to write one more to you (something worthwhile for a change) to help out with the remaining dyno time (or the 230/250 project?) if you need some additional help.

Let me know.

Russ

Thanks russ, thats what this is all about. Helping to provide accurate results for everyone so they can select the appropriate parts for their engine projects. We are revealing many good finds with this dyno testing, confirming many long time claims about some products, and disproving others, so when the time comes for people to spend their money on their projects, they will be able to go in the right direction and make the correct parts selections.

OK, guy's
Going to start another thread for the 250 dyno challenge. Lets direct any 250 info there.

I'd like to keep this one all "292"

Tom

Tom
Try dejetting that 600 down.To the jets of a 500 or 550.

Torque will be less on the 292 & for the 250 engines.

Your dyno testing did not start off of idle.

You said it started @ 2500. That is not from off idle,,,thats where I am saying you will see the difference (IE less torque w/the clifford),,,from idle to about 2200-2500 RPM

Dyno tested is good up to a point,,but testing & tunning a vehicle for the street is a bit different.

Looks like you did a good job,,congrats!


MBHD

Sounds like Leo's going to have to start the third version of the Power Manual to inlcude all this new information. COOL!!!

Chevy2, we are actually going to take that opportunity ourselves....

Hank, dyno's don't like to work below 2500 for some reason, most shops don't even go that low. They are looking for peak HP and most don't care about torque. This group of tests is about as good as gets. Sounds like each piece was given a fair chance to perform in a bolt on situation. Sure tuning might get a bit more power, but they didn't have time and the end user of the said product can do that for them self.

Your right about the off idle torque of the 292. Back when I was racing Pontiac's my 455 broke the block so I threw the heads, intake system, and cam into a 400 block. Other then cubic inches, they were just the same. The 455 would et quicker due to off the line torque, but the 400 would out mph it due to rpm. I would bet the 292 and 250 will act just the same. The 250 will make more hp at higher rpm, but the 292 will make more torque across the board.

This will be a true case of bolt on side by side tests.

Joe

At the dyno shopp again this morning.

It is running cleanly again. Dist fixed it, drats that thing cost me some time!
Just finished running a 194 head with 1.94int and 1.6 ex, lumped and ported, 270 Clifford cam. Off it comes and on to the next head.
Back to the dyno room, now , where is all the extra hands? They were here last week, miss them today. No problem, got a few guys that can help. Tom

What distributor are you using now and which one screwed up??

He started off with a brand new D.U.I. distributor, he replaced it with a stock HEI with a remote coil.

The replacement is almost stock. Does have a curve kit.

Dynoing is done for today. Ran into a snag. Screw in studs contact the rockers when lashing. It is weird as this is not the first head to screw in studs by me. need to take another appr .200 from the boss's. allready took .375 from them.

This is the latest GM casting. I have 5 of them and they are clearly different than any other late model head ever done by me.

They weigh considerably more than other castings also. Plenty of meat. Try more on monday. Tom

It speaks well of your prep that you made this many runs before finding factory crap that shut you down! Please don't quit now. I wish I could be there to help you cuss! That is an area where I excel! Beater

No quiting here!
The head has to come off, be disassembled and machine down the rocker stands more.
Then back together and run it! Going to test with no lumps, my HI-FLOW lumps and PES lumps. Should be interesting.

Jalopy and beater and Joe larson and others,
Thanks for the additional help with the financial part of this.

I heard from my lady that is doing up the dyno runs. Had her average each different set of runs into 1 run to be fair. Should get them sent out to you guy's on Mon. Tom

Tom,
Sent an additional check to help cover the completion of your project.
Bob

thanyou Bob!

Sent out in email to the contributors the results from the runs made the 1st weekend. Any questions please ask.
Remember the lower end consisted of:
Venolia forged pistons 27CC dish
reworked rods
balanced rotating assy
nearly zero decked, .041 thick head gasket, the 1.84 lump head was 70CC chamber, stock heads were around 74CC Cam specs were given out in earlier emails. if you need them also tell me.

A holley 600 carb was used for all tests. Vac secondaries.


If anyone was omitted from the email , let me know. My email is tom@12bolt.com .

Tom,

Thanks for the e-mail, and I anticipate the rest of the results.

Is there anything you need to help with finishing off the test runs? A few more bucks? A few cold ones? A c9ouple hands to turn wrenches?

-Sam

For the remaining tests, more hands would be very helpful. Need to pull the head and make lump changes, more cam changes. It is all time consuming.

With 2 guy's wrenching it took about 45 min to change the cam. Hard to believe it takes that long.

Head change was about 1 hr. 3 guy's just help speed it up. The beer goes faster too! Actually the beer was saved for later. Tom

p.s. I am still recieving funding from you guy's. Got some today from Russ king and Matt(slow65impala). So you guy's are certainly helping from across the country. This will still help with paying for the dyno time. Plan on hitting it again on Sat maybe earlier. Tom

Glad to hear the "fix" was as simple as a distributor.

Bummer to hear there are more issues.

Good luck, perseverence will win in the end.

If I can scrape up some extra cash I'll send it your way.

Thanks, nex

Got some more good news. tried a different brand of rocker stud and gained the necessary clearance for the rockers! Started her up and she just purrs. Will run it on Thursday and keep on going. Tom

Tom, When you have time can you give us the specs on the rocker studs? That is one of my next purchases. I'm looking at 7/16 BB screw ins and figured they were the same. No hurry, take care of this first. And you're right this is good news, less for you to do! Tom

Beater,
I am using BB chevy rocker studs on all the inline heads. Have been using just about any brand and been just fine. the problem we ran into is these particular castings are somewhat different, cast in the 90's. The rocker stands must be taller and thru us off with the normal amount to be taken off. We ended up using ARP brand rocker studs. The portion where the bolt head is has less thickness for the head(top to bottom). Gave us the room needed this time to clear the bottom of the rockers. This head will still get remachined after all the running. It will probably see another 25 or so runs. Tom

Tom, I am a little late but still hope you have some use for the contribution I sent.

Lennart

Lennart,
Thankyou, yes there is still more going on with the 292. It is really great to see someone help from the other side of the world!

Ran the high comp "194" head with 1.94/1.60 valves on Sat. Found out some surprises in the power.

Tonight ran a 1.94/1.6 72CC head with no lumps and boss removed, on Fri even pull it and install HI-FLOW lumps and run again, then pull and run PES lumps. Should be interesting.
Presently the cam is a Clifford 270H.

Get back to you guy's later. Tom

Just got back from the shop. The 292 just keeps on ticking!
At last compression check had 150 psi on all cylinders.
Presently using a Clifford 270H cam , lumped 1.94/1.6 72CC head and getting 280HP. It holds over 270 hp for over a 500 rpm range. Today tried mainly different styles of lumps and other intake/exhaust ideas.
Next I will change cams and try to turn up the torq. Tom

Tom,Looking at the chart you sent it looks like there are 3 cams yet to go? Will the rest be done with the small chamber head only? Will you be changing lumps or have you settled on what works? 280 is pretty serious streetable hp. That setup in a little Nova would be a Kick! Hang in there, Beater

Beater,
I am hanging in. Arms and shoulders are feeling it from all the head lifts, those things are heavy and the 292 is a tall bugger on the dyno!
Have some nice handles made by a fellow inliner that work great with 2 people. Still a grunt though.

After todays runs, not sure about the 2 biggest cams. Typically , we have been shutting down the run when max HP has been reached. Well with this cam, Max HP was around 5200-5300 rpm. Which meant revving to 5400-5500 for the dyno to get good readings. That is more RPM than I like for a 292 with it's big stroke. This one is balanced, and nothing has shook loose , yet. But these are known for problems around this rpm.

This cam has specs of .524 lift and duration of 214@ .050. So not a big cam, I was surprised to see it liked the rpm so much. In fact it sure sounds tough @ 4700 to the end of run.

The next cam is a split duration grind, with more duration on the intake than the cam just used.
specs are :
.521/.512 lift 218/212 @ .050 and 114 lobe separation.

I think it will make more tq. But that is just a theory.

One other thing is , the shop is ready to get another motor on the dyno. I have been very lucky that this is a slow time of year for them.

So this next cam may be it for this session. Tom

It must be a awesome sound at those rpms! You have done a lot already and we will have a lot to ponder, a lot more than we've ever had for street engines. Beater