Pix of blower and now tech discussion on compression/boost [Archive]

Greg@GLD

08-20-2004, 10:05 AM

Complete system:

http://www.midwestmustangassociation.com/vb3/photopost/data/506/1DSC05242-med.JPG

Powerpipe to stock inlet comparos: Look at the difference!

http://www.midwestmustangassociation.com/vb3/photopost/data/506/1DSC05243-med.JPG

Powerpipe inlet:

http://www.midwestmustangassociation.com/vb3/photopost/data/506/1DSC05245-med.JPG

Crappy "stock" Vortech inlet (which I used to run on old combo!)

http://www.midwestmustangassociation.com/vb3/photopost/data/506/1DSC05244-med.JPG

This thing is not very old! Only 1.5 years. :D

http://www.midwestmustangassociation.com/vb3/photopost/data/506/1DSC05246-med.JPG

My dash mounted boost/FP (won't use FP will use cowl mounted guage)

http://www.midwestmustangassociation.com/vb3/photopost/data/506/1DSC05247-med.JPG

Also, been hearing how people have been talking about my plans, bad combo, too much compression, blah blah (heard some interesting stuff last night at RSD about the Oscar's crowd and the comments about my combo :hehe: )
Had a great discussion with Rick Anderson this morning about compression and boost, he said a lot of what you read and hear (some of it I have subscribed to I must admit!) is pretty much "old wives tales" and he said my combo should be solid and as long as I keep timing in check and use good quality fuel, there should be no problem whatsoever. He said it's better to have a little higher compression and keep the tune under control than to have a dog with low compression. The difference in power is huge. SO I guess I just need to be careful of the tune and go from there. Some of the "experts" out there that have been chatty about me have popped motors themselves, so **** happens, know what I mean?? :D I do not plan to go crazy and run a smaller pulley, I will run this combo as is. Should work well. I sure hope so. Damn! I am excited and nervous at the same time. :rockon: :banana: :p

Fatstang

08-20-2004, 10:09 AM

Looks nice Greg, but shouldn't you be getting some rest? LoL

Greg@GLD

08-20-2004, 10:10 AM

I'm too excited!!!! LOL... Have to work a 1/2 day, will get home early and take a few vicodin and go to bed early. :D

Fastlxtasy

08-20-2004, 10:42 AM

Greg....What is your compression ratio anyway?? I have this S-Trim sitting here but afraid to put in on as I was told 10.8:1 is to high of compression, which is what I am running.

Thanks, Jason

prostang92

08-20-2004, 10:54 AM

wanna sell my 9-1 lightning would love it .... :)

Greg....What is your compression ratio anyway?? I have this S-Trim sitting here but afraid to put in on as I was told 10.8:1 is to high of compression, which is what I am running.

Thanks, Jason

Kirk

08-20-2004, 11:11 AM

I have seen those "stock" Vortech inlets. What were they thinking???

86merc

08-20-2004, 11:12 AM

I do not plan to go crazy and run a smaller pulley, I will run this combo as is.

I am sure that is your intention as of right now. But we know what usually happens to us gear heads. LOL

I am sure it will run great. Just put it together and prove all the talkers wrong.:shifter:

Greg@GLD

08-20-2004, 11:30 AM

I am sure that is your intention as of right now. But we know what usually happens to us gear heads. LOL

I am sure it will run great. Just put it together and prove all the talkers wrong.:shifter:

Well... I might have to wipe some egg off my face. I dug out some info from when my 347 was built. All I can say is "uh oh..." :(

grrrrrrrrr.... :thud:

Greg@GLD

08-20-2004, 11:44 AM

I'm gonna be "ragged edge". Been looking up old stuff, I should have done this before.
Might be able to get by with it, but it is on the high side for boost. I have Rick Anderson telling me one thing, I have Ron Robart telling me another. FWIW, Ron says I should have spent that 1600.00 on a set of better heads and kept the juice. Too funny. Argh...

NitrousEdge

08-20-2004, 11:57 AM

LOL

ALL WAYS to many 'what if's' in cars buddy. Put some good gas in it and be conservative with the timing and you'll be ok. Look at the heads up racers in NMRA/FFW with limited pulley size you know they are running high compression to get some of the power levels that they are getting!

86merc

08-20-2004, 12:06 PM

Ron says I should have spent that 1600.00 on a set of better heads

What is the compression higher than you thought?

The next $1600 you spend on the car can be on the heads. Well after the roll bar that is. :thud: It never ends. I feel your pain. lol

Greg@GLD

08-20-2004, 12:13 PM

No, but I trust Ron Robart. He has me worried now...

clayton bigsby

08-20-2004, 12:15 PM

how much boost will you be running? are your heads notflowing enough for the blower that you would need different ones?

BlackLX

08-20-2004, 01:59 PM

Looking good Greg-

I can't wait to see how things pan out for ya. Keep us updated on the install.

DirtyMax

08-20-2004, 02:43 PM

No, but I trust Ron Robart. He has me worried now...

Did he say anything about your odds of "keeping it together" increasing if you pully up? Granted, you're losing boost but some is still better than none, right.

dave bandt

08-20-2004, 04:02 PM

I do not plan to go crazy and run a smaller pulley, I will run this combo as is.

That's what they all say in the beginning!!!! :D We'll see in a year if that still holds true. :shifter:

Greg@GLD

08-20-2004, 06:19 PM

Ugh... been agonizing about this all day. Talked to 4 different well known tuners. Ron Robart thought I had 10.6:1 compression- and I would agree that obviously would be way too much compression, but I found my build sheet, it says "Probe Oil Control Pistons 10.25:1" which is probably still too high. :( But Rick Anderson said there's too many varibles besides compression ratio. He said the cam was a factor, and told me to check compression pressure and average it out. He said if I was above 170 in any cylinders that I might have problems. I checked this afternoon and found average around 150, but he said that the guages he has seen can vary greatly between them and could be off by a lot. Bounce back to Ron from Fox Lake- He says that Rick is WRONG and that static compression is all that matters and 10.25:1 is too much.
Now toss in a discussion I had with Paul Svinicki and he sort of agreed wth both Rick and Ron if that's possible- but he explained it well- He also did agree with Rick's idea to do a compression pressure test, and gave the same threshold. He made me laugh because he asked alot of questions and I told him about the juice and now the car runs with/without it, and he felt the best combo for my 347 was a 150 shot. ;)
But he also said that he thought Rick knows his stuff when it comes to 5.0s and supercharging.
I have this sick feeling in my gut. I know if I press forward with this and have ANY sort of problem, I'll hear the "I told you so's" but I really don't care about that, I heard it all before anyway.

I do know I have a great running setup right now and there's no need to rush forward, but I think any one of you can relate to how I'm feeling- Here's this blower sitting in my garage and I'd like to try it out. One thing Rick said that I think I may do- he said if I am so worried about it, I should pully-up the blower one size and run the powerpipe, that this will decrease charge temps and I will end up with the same boost level as if I had no powerpipe but will spin the blower slower.

What to do, what to do?

Jason- if you read thru all this blah blah blah- to answer your question- I would not run boost with your setup, that's clearly too high man...

BBATCO1

08-20-2004, 06:38 PM

Buy some big chamber aluminum heads(to get compression in check) that flow like a river. Strap the blower on with the smallest pulley available. Tighten the belt till it about snaps off. Then.................Floor it.

BBATCO1

08-20-2004, 06:41 PM

Thats what i would do anyway. I would hope you could find the limits of those new tires also with that tune-up....

Greg@GLD

08-20-2004, 06:42 PM

Danno, this is what Rick said too, but he said the only real way to know is to CC the chambers. I do have 64's, and now your info has me wondering even more now, because Rick said Probe's compression rating was based on 62 CC; Robart said 64.. :thud: See what I am going thru??? But this is why Rick said the thing to do if I do not want to pull a head and CC it is to take compression pressure readings. He said if I did have higher than 170 readings then I should change the heads or the pistons. But he said if I am under that, and I appear to be well under it, I will be ok...

Where did you find your chart info? I know for sure I have 64CC "blower heads" and I know for sure I have Probe Oil Control pistons "10.25:1"
Would be fantastic to find I am in the high 9's.. Rick said that was perfect, that not enough compression creates a "slug" motor and people get too conservative and go too low.

Are we confused enough yet? This is turning into a great tech thread though!!

Greg@GLD

08-20-2004, 06:43 PM

Greg@GLD

08-20-2004, 06:46 PM

No part number listed, only says "Probe 10.25 to 1 (oil control)" on the build sheet Danno. Thank you by the way for taking time to research this issue.

Greg@GLD

08-20-2004, 06:48 PM

Have your heads ever been milled? That will change your 64cc's also.........

Now its getting deep into thought. You may want someone to knock me out before it gets too bad!

Yes they were but only a little bit, and also, my block has been decked and squared... And the price of potatos in Ireland has risen 18% this year...

Greg@GLD

08-20-2004, 06:53 PM

I take it this is the chart?

http://www.probeindustries.com/Pistons/Pistons_SRS/Ford/302/Ford_347_ft.htm

Jesse James

08-20-2004, 06:57 PM

Know anyone with a "Caison" style guage Greg? Reads absolute pressure and extremely accurate, that would give you your cylinder pressures to a knats ..... Some even have the 14.7 or one atmosphere already calibrated into the guage.
I think someone already mentioned it? Are your heads O-ringed or a little thicker gaskets?

Greg@GLD

08-20-2004, 07:05 PM

James, I don't know. Dudes, I've had so many combos and done so many things, I don't even know anymore. I have had these heads for 6 years, they have been repaired twice but it was valve guide work, they were "shaved" to clean them up, I have no reference on this though as to how much.

dave bandt

08-20-2004, 07:14 PM

OK Greg....you're beating yourself to death on this one. I ran some numbers with typical values i would assume from your engine based on what i've seen building them. They are as follows....

Stroke 3.40
Bore 4.03
HG Compressed Thickness 0.038
Gasket Bore Diameter 4.100
Deck Height 0.000
Volume Above Top Ring 0.5 CC's
Valve Relief Volume 4 CC's
Chamber Volume 64 CC's

This give 346.6 CID and a compression ratio of 10.25:1. Not bad for a guess, huh?

If you put a set of 0.060" thick Cometics in it your compression will drop to 9.7. A set of 0.070's will give you 9.5:1. And for every 0.005" your piston is in the hole you loose another 0.1 points of compression. I say put a set of 0.060" thick Cometics in it and forget about it.

Then again, you can talk to a friend of mine named Jay Allen. He's a cam specialist that is doing some very different stuff with blowers. He'll tell you to leave it alone and put one of his custom grinds in it. They've got a blown SSO car that goes WAAAY against the grain with contemporary blown engine design.....but it's not a street car.

dave bandt

08-20-2004, 07:17 PM

BTW, cutting a couple thousandths off to clean the deck will have little to no appreciable effect on your compression ratio.

Kirk

08-20-2004, 07:19 PM

See, more opinions.

Oh and Bah to the haters. :D

Jesse James

08-20-2004, 07:22 PM

Well for what it's worth Greg, if there is a dive shop or salvage diving business in your area you may be able to rent the guage. They usually have a few that read in tenths, and hundredths. These guages are also used for calibrating many other heavy equipment/machinery for lifts, static pull tests, etc etc. A calibrated guage like this with a scale of 0-200, 0-500 would work great and eliminate your headaches on the "real pressure" in each cylinder. Hydraulic shops may have a few also for test benches/calibration, QA work. Just a thought man, trying to assist.

Greg@GLD

08-20-2004, 07:28 PM

Wow, thanks for the replies!
Dave, great stuff, thanks!

James, I can try and find one, and you ARE assiting. I appreciate it.

Kool Rock Steady

08-20-2004, 08:00 PM

Greg get a set of MLS gaskets and have them thicker. That will help a little with cr or have the heads opened up in the cc area to lower cr. :D

BTW, what is your cr?

Fastlxtasy

08-20-2004, 08:11 PM

Lots of excellent info in this thread. Beings all my cylinders are about 190 compression Greg, I will take your advice and not even think about installing it anymore.

Saltmaker

08-20-2004, 08:14 PM

dave bandt

08-20-2004, 08:33 PM

Lots of excellent info in this thread. Beings all my cylinders are about 190 compression Greg, I will take your advice and not even think about installing it anymore.

Cranking compression is more of a function of valve timing than static compression ratio. My motor is over 14:1 and my cranking pressure is less than yours. Does that mean you have more compression than me? Or do i just have a lot more overlap/duration than you? I'm not being a smart ass.....just trying to make you think about things a little differently. ;)

1slo5.0

08-20-2004, 09:12 PM

You only live once Greg...............

Fastlxtasy

08-20-2004, 09:15 PM

NO CHANCE

08-20-2004, 09:27 PM

Not to jump in, but doesn't it matter how much boost your going to run? The higher compression the less boost you need to make power (within reason)? I would think if its a little higher then you want just lower the boost some?

This is the key...lots of racers running serious compression on power adder cars. More comp = less need for boost. Just keep good fuel in it, and don't get crazy with the timing. I think it might shock you to know what CR some of these cars run. It's a ton higher than any of the numbers discussed here.

Greg@GLD

08-20-2004, 09:35 PM

Cranking compression is more of a function of valve timing than static compression ratio. My motor is over 14:1 and my cranking pressure is less than yours. Does that mean you have more compression than me? Or do i just have a lot more overlap than you? I'm not being a smart ass.....just trying to make you think about things a little differently. ;)

See Dave this is what Ron Robart was trying to say- that what Rick Anderson said is WRONG and that I have 10.25:1 compression and should not run boost, any boost, nevermind what the cranking compression is. And you seem to confirm this. Then Paul Svinicki said yes, that's correct "to a degree" but then said the same thing that Rick said and that cranking pressure in excess of 170PSI was sure trouble, but in the range I am showing it isn't, and that it's likely that I don't have 10.25:1

If I am going to pull the heads I'd just as soon put something back on the car that more suits what I am trying to do.

I'm taking the Cobra to dyno day and will dyno it as is for the hell of it.

Greg@GLD

08-20-2004, 09:38 PM

This is the key...lots of racers running serious compression on power adder cars. More comp = less need for boost. Just keep good fuel in it, and don't get crazy with the timing. I think it might shock you to know what CR some of these cars run. It's a ton higher than any of the numbers discussed here.

OK so Jerry- Rick Anderson, as I mentioned a few replies back, said if I am so worried about all this, I should underdrive the blower and run the powerpipe- this will lower boost but also reduce drag on the motor and increase blower efficiency. SO perhaps the thing to do is go with the underdrive blower pulley to start out with?

BBATCO1

08-20-2004, 09:48 PM

Greg@GLD

08-20-2004, 10:00 PM

There is alot more to static compression ratios than head cc's and piston charts. most builders coulde'nt tell you truthfully the compression of your motor beacuse they don't want to spend the time finding out. You will also need to know where the piston sits in the hole, how thick a head gasket and so forth. I would do whatever Rick says along with having him tune the combo. I don't see how you could go wrong he has provenb his skills time and time again......

Bravo! I think the same way- He didn't bash Fox lake (Robart) he said "Greg we do a lot of different things, we build N/A, Nitrous and blower combos, we are always trying different things. You do what you think is right, I'm not going to tell you you will not have problems, you could pick all the "right stuff" and still blow it up if the tune isn't right. I think you worry too much. Quit thinking too much..."

dave bandt

08-20-2004, 10:29 PM

I think you worry too much. Quit thinking too much..."

We're all guilty of that to some degree. :D

Greg@GLD

08-20-2004, 10:37 PM

Dave I know how busy you are with work and your own racing program, thank you for taking the time to help us. Same goes for eveyone who contributes here.

JOHN 86GT

08-20-2004, 10:39 PM

. I think you worry too much. Quit thinking too much..."

Easy to say on your "dime"! :eek:

:

quietflow

08-20-2004, 11:33 PM

Great thread lots of good info. Good Luck Greg!

JOHN 86GT

08-21-2004, 08:24 AM

[QUOTE=dave bandt]
Then again, you can talk to a friend of mine named Jay Allen. He's a cam specialist that is doing some very different stuff with blowers. QUOTE]

Wouldn't a different cam bleed off a little compression?

I talked to Jay a few times in 95 or 96 (at Milan and GLD) very smart guy. Not too many guys in the 9's (efi on motor) back then. I like to read the cam wars over on Hardcore50 :D

bobtodd

08-21-2004, 09:13 AM

Compression/boost discussion......deja vu

Mark302

08-21-2004, 10:50 AM

Just caught this thread. They also told Mike that he had way too much compression. He has almost 10.25 to 1 and is seeing 21.7lbs of boost. He runs just reg. Turbo Blue with no problems at all. I say , if it were mine, I would put it on and not tune down the boost. Good Luck whatever you decide though.

bobtodd

08-21-2004, 11:12 AM

I agree with Mark. One way or another it will work. I'd give it a try.

dave bandt

08-21-2004, 01:21 PM

Wouldn't a different cam bleed off a little compression?

Cylinder pressure is what makes power, regardless of how it is made. Cams cam bleed off pressure....i.e. from a static compression ratio. Or they can also increase cylinder pressure by closing the valves earlier relative to the piston location. Jay likes to use very high lift short duration cams. The short duration closes the valves earlier and builds more cylinder pressure as compared to a similar cam with more duration. So to answer your question....yes, a cam can bleed off cylinder pressure.

BTW, I hear you about Jay. He worked with Billy Glidden for a while and at Canfield designing heads. One sharp cookie. I'm gonna try one of his cams next year on the dyno. I would have done it this year but i have to make some changes to my heads first....i.e. all new valves.

Kool Rock Steady

08-21-2004, 06:59 PM

Greg, just put stock pulley on have it tuned on dyno with a/f and go from there. If your around or more then 500 then you are starting to live dangerously

bad boy

08-21-2004, 07:46 PM

Lots of excellent info in this thread. Beings all my cylinders are about 190 compression Greg, I will take your advice and not even think about installing it anymore.

Do you want someone to take it off your hands? :hehe:
Good luck with the car Greg. I think you can make it work.

QTRMILE

08-22-2004, 08:50 AM

BTW, I hear you about Jay. He worked with Billy Glidden for a while and at Canfield designing heads. One sharp cookie.
Oh yes he is. I've talked to him on the phone a few times, and he is a VERY nice guy. He called me back and answered some questions about a blower combo I was working on RIGHT AFTER his house had caught on fire. I mean the guy's house burns down, and he takes almost an hour out of his time a day or so later to help me. Jay is a good guy who knows his stuff. And I like his way of thinking; somewhat "outside the box..."

Greg@GLD

08-22-2004, 07:27 PM

I remember when Jay was very active on The Corral, but he got flamed because he was too smart I guess. Remember that Rob???

Anyway, as I posted in the "Blame it on Mark302" thread, the blower install has commenced. Should have a blown up motor before the season is over...

BBATCO1

08-22-2004, 08:01 PM

After this ones done its time for a Procharger for the Mach. That would be badass....

Greg@GLD

08-22-2004, 08:09 PM

After this ones done its time for a Procharger for the Mach. That would be badass....

Oh no!! Here's some fun discussion! One of the things Paul Svinicki mentioned was how people are blowing up supercharged Mach1's left and right! They have in excess of 10:1 compression... :thud:

NitrousEdge

08-22-2004, 08:15 PM

They also have crap internals....no offense

Greg@GLD

08-22-2004, 08:30 PM

They also have crap internals....no offense

For a blower, yes. Same garbage as Nice Asp came with stock as far as junk brittle pistons. Now she's got forged internals, not the same thing. I also remember getting an honest 500 blower passes on that crappy shortblock before it let go... :thumbs_up

Mark302

08-22-2004, 08:56 PM

It aint blowin up. You worry too much.

Exactly. You'll be fine.

NitrousEdge

08-22-2004, 09:03 PM

For a blower, yes. Same garbage as Nice Asp came with stock as far as junk brittle pistons. Now she's got forged internals, not the same thing. I also remember getting an honest 500 blower passes on that crappy shortblock before it let go... :thumbs_up

The weakest part I have seen is the rods. Two guys I know of have shot rods out the side of the block on a 100 shot!

What the difference is between the Mach 1 and my motor is I couldn't tell you (or any other early mod motor for that matter)

Greg@GLD

08-22-2004, 09:14 PM

I have Eagle H-Beam rods in the Cobra.

I'm not doing any power adders on the Mach1. Couple guys running 100 shots on my Mach1 site, so far, so good.

Greg@GLD

08-28-2004, 01:41 PM

Well to close this discussion... Above 5 PSI it rattles bad even with boost retard cranked all the way and timing retarded to 10 degrees base.

So much for that... :(

MAT88GT

08-28-2004, 07:26 PM

lol Greg relax man....you should have piston to deck specs from your 347 build I hope...
the rest of the variables have fudge factors that you can work with to calculate compression. But! guess what, It doesn't matter.

Valvetiming has more to do with limiting boost/compression (static) than anything else.

Bottom line, keep a decent quench distance, good gas in the chambers, conservative tune, and you'll be fine and dandy. Don't toss in thicker gaskets, especially if your pistons are in the hole...bad news there. Keeping things cool is very important as well.

That little 347 stood up to the nitrous w/o any problems...the supercharger wont be any worse ;)

You can't generalize a boost pressure limit per a given static compression ratio. Pressure is relative to the top end combo (pressure differential through the intake/heads), static compression doesn't mean much unless you're using all that is available, dynamic compression plays a larger role