how much nos i can use on a high comp, tight engine?

[kickin472]

I have a smallblock 472 ci sb2.2 domanater carb flows at 1279 from dan davinci, running 18:1 compression.6500 -7500 rpms at the most down the track. i use torco 118 nos fuel. We mud drag race 200 ft at a time.
I have to move up 2 classes to mods, this is a buggie nos class so i need to be competative. my engine is completely setup to be n/a so what nos package can i use without tearing down the engine. I dont have tappered wrist pins but everything else is pretty much best of the best. I guess i would like a nos system that doesnt come on when i w-o-t it but maybe toggle switch it like at half track or when i fill the need because i have more than enough hp at the starting line. I have a msd retarder box on it now retarding the timing 4* at 5000 rs to keep detonation down and a little extra top end power. Thanks guys.

Anthony

[edvancedengines]

running 18:1 compression.

Excuse me for not agreeing, but I don't think so.

Possibly you or someone is not measuring or figuring it correct?

Ed

[cepx111]

18 to 1????, its almost a desiel engine.

[kickin472]

why is that hard to believe? my sb2.2 heads have 33cc or 38 cc chambers cant remember exactly off hand without getting the paper work out my engine builder and i talked this over and i recall him saying 18:1 would be the most i could run on pump gas before some kind problems would come into play with my setup. so we got je involved in on this also. This is why i use torco 118 nos fuel its 120 motor octane. So Ed why dont you explain to me why I couldnt possibly have 18: 1 comp. with no power add ons?

[kickin472]

je pistons and brook from callies

piston part# 246642 Acc#3671 Inverted Dome Job # 521517 Po.29313
head desc. sb2.2
bore 108.00mm
Invdome depth .087 (2.21mm)
top ring 1.2 mm
2nd ring1/16
oil ring3/16 + spacer
comp. dist1.170 (29.72mm)
Int .300 (7.62) 11 deg
Exh .075 (1.91) 8 deg

Grove Land
top .0475 (1.21mm) .300 (7.62mm)
2nd .064 (1.63mm) .160 (4.06mm)
oil .218 (5.54mm) .085 (2.1mm)

in Dia .927 (23.55mm)
Pin Length 2.750 (69.85mm)



Actual weight 498 grams

Set to Clearance to .0050 (.13mm)

Block Height 9300
-1/2 of stroke 2.125
Rod length 6.125
Deck Clearance - 005
Compression Height 1.045
0.40 head gasket thickness

[cepx111]

Weather you have 18 to 1 or not, it's very uncommon to run that high of compression and no I wouldn't advise running nitrous. but then again I'm not real familar with the sb2's and what they can handle, maybe a standard 150 plate system wouldn't be to much? or a small fogger but either way your gonna want to get a programable nitrous controller to control detonation in a motor that's already prone to detonation refering back to what you stated, so I'd say you would be flirting with disaster by adding NOS to begin with.
I do know sb2's are nascar based engines and that they do run some pretty high compression ratio's to get the hp numbers they do, but then again they run their rpm's much higher than what you stated you were running yours at, perhaps all you need is more gearing to tap into the upper rpm power that's already there?
goodluck, Charles

[rabiddawg]

instead of NOS
I would switch to alcohol at 18:1 compression
NOS will ruin a motor over time.

[kickin472]

instead of NOS
I would switch to alcohol at 18:1 compression
NOS will ruin a motor over time.

Thats why we stopped at 18 with my setup, thats when my engine builder said you would start having pump gas issues and would have to switch to alcohol and the class i was in didnt allow it.
Isnt that pretty much a small gain switching to alcohol? I know it runs cooler. Would like to possibly use 100 - 125 - maybe 150 shot of nos (would like to have more, but will refresh next year and do it right for nos) we only run 200 ft. so nos would only be on for 2 - 2.5 seconds.

[cepx111]

If your going to run nitrous, use it at the lowest level and start working your way up, dont just slap a 200 shot on and hope for the best.
NOS systems makes an entry level kit called "the sniper" and its adjustable from 50hp all the way up to 150hp. You can activate it via a w.o.t. switch or you can activate it with a toggle swicth or some other type of pusbutton switch like a trans brake button whenever you want alittle extra.\
I used this same kit to much sucess in a footbrake bracket car and would only use it when I was either a tad late on the light or I just felt like I wasn't catching the car liek I thought I should be. Also fun to make a full nitrous pass after the races slowed soem at the end of the night. Warning though nitrous is very fun, addictive, so use with caution.
Alcohol would give your motor much more torque and a few more horses especially with the comp your running but I see your class has resistrictions so that's out of the question.
Nitrous would really wake up your motor and it doesnt take much to make big changes going down the track. Things will happen in a hurry so be careful.
Here'a link to the kit I was refering to.
Goodluck, Charles

http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_745476_-1_12043

[billhendren]

As someone who builds a ton of SB2.2 engines both for circle track and drag race I agree with edvancedengine something doesn't sound logical, first off 108 mm is 4.251 what block other than the new billet 4.5 bore spacing will handle that bore size. second 18.0-1 is diesel range. once you get above 15.5-1 we have found almost no gains in torque. we have several engines out there at 15.0-1 with a 400 shot and no problems. with a 1.045 c.d. and a .300 deep int pocket there is no room to run N20,the piston will fail at the int pocket.Bill

[gimmemud]

I would strongly advise you not to do this, with that much bore on an iron eagle block (I assume) you dont have enough head gasget surface for nos. Why do you have to bump up 2 classes? From what I see of your truck from the pics, looks like a pro street or pro stock at the most. I have Iron eagle block and was advised not to exceed 4.175 bore for nos.

[edvancedengines]

Beats me what Brook (a salesman at Callies) has to do with this, unless he is the one who told you about the 18.00 -1 compression.

You sorta left out some ital inormation for anyone to figure your static compression ratio. What is the dome or dish cc of your piston? and what is all of this posting in mm of all the dimensions? We are in the US of America.

If your engine builder is making that thing to run and live on pump gas with 18.00 -1 compression he knows far more than I, or anyone else on this forum or for that matter any professional engine builder I know.

It might be interesting to figure your compression if there was information to do it with. You gave everything except for the piston cc. I do refuse to take the time to convert anything from mm though. NHRA Pro Stocks do not have that much compression. Comp eliminator engines don't, and I know of no cup or NASCAR engines that do.

And you are saying that this is on Pump Gas?

Ed

[gdmii]

Just so you don't think Ed is picking on you, I'll chime in that I agree with him. 18:1 on any pump gas just ain't happening. 11:1 maybe...10:1 to be safe. Even if you did go to alcohol, 16:1 is about the max there. If any engine builder told me I could go to 18:1 on pump gas, I would be running away as fast as I could...if I could stop laughing long enough to run that is.

George

[gimmemud]

I think what he is calling pump gas, he means racing gas not methynol

[edvancedengines]

George,
You are right. I am not picking on him. I am an equal opportunity picker. ;) I pick on you or anyone else. :) I pick on myself more than I do anyone else though. No one is as critical of me and what I do as I am.

Hey, Did you usd to have a MSN GRoups called Pro Street? I think it was. There was a guy there that always had bad to the bone rides named George. Hot Rod Harley was also on there.

Ed

[gdmii]

Sounds like we had a lot in common :D but, no, that was another George.

George

[kickin472]

Just so you don't think Ed is picking on you, I'll chime in that I agree with him. 18:1 on any pump gas just ain't happening. 11:1 maybe...10:1 to be safe. Even if you did go to alcohol, 16:1 is about the max there. If any engine builder told me I could go to 18:1 on pump gas, I would be running away as fast as I could...if I could stop laughing long enough to run that is.

George

Geez you guys are ready to pounce like a lion, lol. Anyway Yes I said pump gas meaning no exotic fuels I have stated a couple different times that I use Torco 118 nos which is 120 motor octane. I have the piston paper work here and my bore is 106.30mm (4.185) not 108mm as i thought, The cc chamber is 44. everything else is as stated.. . I would like to know exactly what I have for compression if someone wants to give me there e-mail to see if it is 18:1 (because It costs me $67 for 5 gallons of 118 nos torco and if it is lower compression might be able to use the 115 - 116 torco.) - business or personal e-mail so they can see the all the specs and sorry Ed this je piston sheet has mm all over it thats why i took the extra time to write them both down for the specs.

[edvancedengines]

ok guy,
I am not dumping on you. I know what is real and what is bogus. I do beleive you feel the info you have been told is real.

I personally know a few of the very best engine builders and very best cylinder head and camshaft guys there is and also ever was. I know for a fact not one of them can make an engine live and run at a 18.00-1 compression.

I persoannly know the guy over the cylinder head development for Hendricks Racing. They build both restrictor plate engines and non- restrictor engines depending on the racing. Even a restrictor plate engine is seldom over 16.00 -1 static compression. Not any NHRA Pro Stock engine builders I know and I know 2 of them who are considered to be among the best, would even attempt to build any engine over 17.00-1 and that is using the VP c-25 125 octane gas. Actually I doubt if any of them are now even 17.00 -1 becuase they discovered no additional power above 16.85 -1 .

I guess that metric junk is just more efforts to kill the JE company like they have been doing since they bought it. Je PPiston company was bought by a huge elevator company to use as a shelter. o'boy.

Still you have never shared with us what the cc of the top of the piston is. I can guess at gasket cc. I can come close to guessing at Chamber cc if I know the head. Piston dome or piston dish cc cam be anything.

What are the cc of the piston? I hope it is a negative number.

Without Piston CC all other talk is useless.

By the way. Whatever it is; That engine in your car in the vid sounds awsum and the car is bad to the bone. Looks like that short wheelbase is killing you though.

MY thoughts are that it is probably a 16.00 -1 or a little higher compression ratio engine which is great on an all motor SB 2.2 head engine with appx a 28 deg total ignition timing. If I am right.

Ed

[kickin472]

ok guy,
I am not dumping on you. I know what is real and what is bogus. I do beleive you feel the info you have been told is real.

I personally know a few of the very best engine builders and very best cylinder head and camshaft guys there is and also ever was. I know for a fact not one of them can make an engine live and run at a 18.00-1 compression.

I persoannly know the guy over the cylinder head development for Hendricks Racing. They build both restrictor plate engines and non- restrictor engines depending on the racing. Even a restrictor plate engine is seldom over 16.00 -1 static compression. Not any NHRA Pro Stock engine builders I know and I know 2 of them who are considered to be among the best, would even attempt to build any engine over 17.00-1 and that is using the VP c-25 125 octane gas. Actually I doubt if any of them are now even 17.00 -1 becuase they discovered no additional power above 16.85 -1 .

I guess that metric junk is just more efforts to kill the JE company like they have been doing since they bought it. Je PPiston company was bought by a huge elevator company to use as a shelter. o'boy.

Still you have never shared with us what the cc of the top of the piston is. I can guess at gasket cc. I can come close to guessing at Chamber cc if I know the head. Piston dome or piston dish cc cam be anything.

What are the cc of the piston? I hope it is a negative number.

Without Piston CC all other talk is useless.

By the way. Whatever it is; That engine in your car in the vid sounds awsum and the car is bad to the bone. Looks like that short wheelbase is killing you though.

MY thoughts are that it is probably a 16.00 -1 or a little higher compression ratio engine which is great on an all motor SB 2.2 head engine with appx a 28 deg total ignition timing. If I am right.

Ed


ok talked with Alex from je and gave him the job# and the piston dish volume is -13.65 ccs. Gasket thickness is 040. the heads are 44ccs chambers. I asked him about the nos and how much and he thought 150 - 200 would be no problem. I remember when these pistons were getting made and had been sent to callies for the complete rotating kit, je engineers called callies and had them send the pistons back to them to redo them because they didnt think they were strong enough for the power and compression or made correctly for what we had going on. It took je over 2 months to get them made and to callies to complete the rotating assembly again.

Your right the short wheelbase is killing, we are extending the frame
26"s to keep the front end down and make it more stable hopefully(If you noticed that video you watched I end up rolling over about half track). This is why I want to put nos on it it now because the extending of the frame bumps us up in a buggie nos class and I want to be competative.
And yes we are at 26-28* for timing and at 5000-6000 i use the retarder to back it off 4*S

Going to post a couple pics of the frame getting extended. After we get that done will put a diamond plate bed on it.

Ok now I think I have narrowed it down to 3 kits here.
1- edelbrock performer nitrous system #70001

2- sniper nos kit #07001

3-zex nitrous perimeter plate system. 249-82048

which one would be the best one or would like to hear other nos kits that
might be better.

Thanks,
Anthony

[edvancedengines]

ok finally,
Now we are getting somewhere and it is looking pretty good.

Bore= 4.185
Stroke = 4.250 (lots of grinding)
Head gasket thickness = .040
Piston deck ht = .005 in the hole.
Appx head gasket diameter = 4.200
Piston cc = -13.65

Real cubic inches = 467.6
Real static compression ratio = 14.91 - 1

Now we are talking horsepower with good living conditions. Took us two days almost to get here but this is the real numbers by the information you supplied.

Please understand that 18-00 -1 compression would blow it's self into pieces not too long after you got it started if you were racing it or running it on a dyno. That is why I had such a hard time believing what to you was simple. I am capable of getting engines to live and run with much higher compression for the circumstances than most builders can and this was blowing my mind.

Can you increase your head gasket thickness and keep same pushrods and rockers etc, by even .010 or .015?

If you can or if you can't, the next info we need from you are as much of the camshaft specs as you have and the rocker arm ratio. For sure I need lobe lifts, lobe separation angles, and duration @ .050

Just as it stands with a retard systen you should be able to spray 200 to 250 shot on it, if your piston and rings will handle it. I will know more when I see the cam specs. The SB 2.2 head is not nitrous friendly but guys do shoot it. The valve angles are too shallow and the chamber is too small. It is still workable though.

The Edlebrock N2o system was designed by Steve Johnson. The only phone number I have for him is personal but you can find him at

www.yellowbullet.com
In a section called Nitrous by Induction Solutions. He does work with Mud Racers.

Ed

[cepx111]

I think we scared him off.
Cp

[edvancedengines]

I am here investing my time and in many instances, far too many, wasting my time to try to help others avoid costly mistakes and to hopefully get it right with the best bang for their bucks.

I enjoy helping. That is never a waste of time. It is a waste of time when I get challanged and argued with by those who have not been in my shoes or known people whom I know and have known in this industry.

It is just like this thread. We have been maybe two days just to find out what should have been told us after we questioned and told him no way possible. Several of us who are in the position and have the experience to know, and we get talked to like we are the ones ignorant. I don't care what an engine guy with no clue, or a magazine article says or what is printed in funny books or the internet. I speak from sitting in the driver's seat and doing it, like many of the even more experienced professionals here.

THis one just like many others is so adamant his engine builder or his information is right, they argue with lifetime experiences of dragging the most posssible power and compression out of many different combinations. On another board, I see guys arguing with Joe Sherman, Larry Meaux, Jon Kaase, Adger Smith, myself and at least three top current cup and NASCAR builders (have to remain nameless)..

I am posting a quote that almost got me to bail out of this thread.
why is that hard to believe? my sb2.2 heads have 33cc or 38 cc chambers cant remember exactly off hand without getting the paper work out my engine builder and i talked this over and i recall him saying 18:1 would be the most i could run on pump gas before some kind problems would come into play with my setup. so we got je involved in on this also. This is why i use torco 118 nos fuel its 120 motor octane. So Ed why dont you explain to me why I couldnt possibly have 18: 1 comp. with no power add ons?

The explantion is easy. several of us did explain it. It is becuase the engine would self destruct with that much compression.


Well' I didn't bail out and we finally found out the missing pieces of the puzzle and now we all know he is possibly safe from harm with good tuning. So to me that is worth the staying here till the information got believable.

Ed

[cepx111]

Finally some real time info.
And to answer your original question, spray the hell out of it but use the necessary precautions mentioned earlier..
goodluck, Cp

[gimmemud]

Hey Ed this looks like a good progect for some more Ed brc pistons.

[gimmemud]

Kickin472 I am tuning the nos on a 434 sb2 motor this weekend for a friend of mine, he is running 16.5 comp and we are gona start out about 150 hp on a speed tech fogger. His engine made 960hp on the dyno na, so I will give you an update on how it responds to the nos on monday.

[edvancedengines]

Kickn472,
I am not trash talking you. Please try to understand how difficult at times this free internet tech service can be for us here only trying to be helpful.

I get hundreds of postings where guys ask for advice or opinions and then spend pages and days telling me I don't know what I am talking about. I am likely bailing out of one now at Speed Talk where a guy came on asking advice and opions and now has begun posting like he knows more than the combined maybe hundred of years experinces of we who were trying to help him.

Now that we have pinned down what you have, I hope you are happy and have been helped.

Ed