lt1 block twisting

[flippy1974]

my motor builder says i might be tiwsting my block its a 383 , with a eagle 4340 crank ,h beams rods ,srp pistons , spayed caped ,hard blocked to the bottom of the freeze plugs . i spray 350 shot on it . is there any thing to hold this from flexing .

[96lt1m6]

you may mant to look into these
http://www.jegs.com/webapp/wcs/stores/servlet/ProductDisplayPopup?storeId=10001&catalogId=10002&productId=763041&itemId=1030245&langId=-1&showValue=1

http://www.jegs.com/webapp/wcs/stores/servlet/ProductDisplayPopup?storeId=10001&catalogId=10002&productId=762154&itemId=536300&langId=-1&showValue=1

[flippy1974]

thanks man i will look into it . how much hp can these block hold ?

[96lt1m6]

since there has been a twin turbo 6spd full weight full interior runnin 9s
Big Dog Taner B. street car, 6spd car 9.08 @155 and a few others i would say with the block prepped properly will take 900-1000hp

[Transamman25]

i have those same valley braces, i also spray 300 shot , with zero issues .. 867 rwhp so 867 x .20 driveline loss = well over 1000

[uncool]

What do you attach the valley bars too? Do you drill and tap into the water jacket?

Thanks.

[Jerry Clayton]

Don't the heads and manifold hold your motor together?

[Grr]

yeah if you are getting up or over 1000hp i would definately look into the valley bars and the crank girdle. I would be suprised that you are twisting it noticably right now with the block filler, but anything is possible. A guy local to me would put bearings in about twice a season when he was in the 1050whp area (25psi) and when he upped it to 32psi it would wipe the bearings in just a couple drives, indicating lots of flex. But at 32psi he was in the 1200-1250whp area

[Fire67]

What do you attach the valley bars too? Do you drill and tap into the water jacket?

Thanks.

I was wondering the same thing. By the looks of the pics I'd say yes? Anyone know for sure?

FWIW, I've always been told that main girdles just hold all the broken pieces in place after they break :metal:

[Jerry Clayton]

If your block is being twisted, it is because your chaSSIS IS TWISTING IT---don't use solid motor mounts and look for ways to stop the chassis twist

[96lt1m6]

If your block is being twisted, it is because your chaSSIS IS TWISTING IT---don't use solid motor mounts and look for ways to stop the chassis twist.

Not true, just by the power from the motor it naturally twists to the right, the only way to control this is to instal motor and mid plates.

[flippy1974]

yeah if you are getting up or over 1000hp i would definately look into the valley bars and the crank girdle. I would be suprised that you are twisting it noticably right now with the block filler, but anything is possible. A guy local to me would put bearings in about twice a season when he was in the 1050whp area (25psi) and when he upped it to 32psi it would wipe the bearings in just a couple drives, indicating lots of flex. But at 32psi he was in the 1200-1250whp area
i put down 6xx hp to the wheels on a 200 shot . im getting a new head and cam package this year that should put me in the 8xx-9xx rwhp and the motor hasnt been out in 3 years , when we tore the motor down all the rod bearings looked like brand new and the top of the main looked like new but the bottom of the mains had some wear but the #4 main was about to spin . so we checked line bore , checked the crank and they were still dead on .
the car has ran a best of 10.45 @ 132 with a 1.6x 60 ft i have it pulling 1.4009 60 ft at the 300 feet track at the end of the summer with the 300 ft time 3.91 .

[flippy1974]

If your block is being twisted, it is because your chaSSIS IS TWISTING IT---don't use solid motor mounts and look for ways to stop the chassis twist
if the pics work , you can see my car doesnt twist ! it pick both front tires up the same , so ther shouldnt be any body twist .plus i not running soild motor mounts there just stockers ! not even poly mounts just stock gm ones .this is the only pic i have of my car at the line , i have draglites on it now .

[MeanGreen94Z]

If your block is being twisted, it is because your chaSSIS IS TWISTING IT---don't use solid motor mounts and look for ways to stop the chassis twist
um... no lol, our cars are unibodies... solid or poly its gonna do the same when it gets to the full travel of the motor mount. solid gets there faster tho... i would do the valley bars, girdle and look into a front plate like JakeZ28 is selling

[jakesz28]

I would say it may be time to do a front motor plate.

http://i97.photobucket.com/albums/l211/jakesz28/12109002.jpg

By moving on to a motor plate it takes some of the stress off of the sides of the engine block. Which will help reduce cylinder disturtion. You can even go as far as running a front motor plate and a mid plate. They will also help stiffen the chassis by connecting both frame rails together.


I may have missed it but what problems are you having that made your engine builder mention this. One thing about doing a partial fill is on the first pass the cylinder is true but with each pass after that or as the block starts getting hot the filler expands at a different rate then the iron block. So most shops will give you a larger piston to wall clearance to make up for that.

[Jerry Clayton]

If you use a solid plate for front or rear of the block you will compound whatever forces you chassis back feeds into the block. The engine will torque over to the right but with no more force than the torque output of the engine.

It is normal for a high power v8 engine to use up #2 and #4 mains because of the crankshaft design. A flat or 180* firing crank doesn't do this.

Your bottom block filler is a waste of time ( or even a determent) for any purpose than to plug the coolant jacket in case the block was ground thru for rod clearance.

Block filler needs to be formulated so as to have exactly the same expansion rate as your block and if used at all should be at the top of the water jacket to support the cylinder walls where the most heat and pressure are.

Unibody---doesn't twist ??? now that is a laugh

[jakesz28]

i put down 6xx hp to the wheels on a 200 shot . im getting a new head and cam package this year that should put me in the 8xx-9xx rwhp and the motor hasnt been out in 3 years , when we tore the motor down all the rod bearings looked like brand new and the top of the main looked like new but the bottom of the mains had some wear but the #4 main was about to spin . so we checked line bore , checked the crank and they were still dead on .
the car has ran a best of 10.45 @ 132 with a 1.6x 60 ft i have it pulling 1.4009 60 ft at the 300 feet track at the end of the summer with the 300 ft time 3.91 .


Just reread to thread and found this. If you are starting to get some detenation it will beat up the bottom of the mains. You can do bearing damage without actaully feeling it. I would watch the plugs and not run anymore timing then needed.

[MeanGreen94Z]

Unibody---doesn't twist ??? now that is a laugh
what i was saying is, our weak ass unibodies ARENT gonna twist a cast iron block, hell our chasi is only connected to the k member in 6 spots by 6 bolts... trust me the rear tires torquing arent gonna twist anything but the tranny and transmit that to the motor mounts or plate

[8SEC6SPD]

hmmm, bad tuneups kill bearings ...period!

don't waste your money on the girdles....why do i say this, because i haven't seen a need for them. they certainly aren't cheap.

just my .02

[flippy1974]

I would say it may be time to do a front motor plate.

http://i97.photobucket.com/albums/l211/jakesz28/12109002.jpg

By moving on to a motor plate it takes some of the stress off of the sides of the engine block. Which will help reduce cylinder disturtion. You can even go as far as running a front motor plate and a mid plate. They will also help stiffen the chassis by connecting both frame rails together.


I may have missed it but what problems are you having that made your engine builder mention this. One thing about doing a partial fill is on the first pass the cylinder is true but with each pass after that or as the block starts getting hot the filler expands at a different rate then the iron block. So most shops will give you a larger piston to wall clearance to make up for that.
thats a good looking plate ! the only problem i see with that , is i cant run a/c . my car is full # + all the, power windows, a/c, power streeing ,power seats , the only thing missing in my car is the spare tire ( so i could relocate the battery) and the bose speaker ( because the roll bar got in the way) .so the plate wouldnt be a option for me right now .

as far as the motor builder , it was about to spin the #4 main bearing and all the rest looked good .but the motor had been in the car for 3 years and hadnt been out so its not like it will happen again over night ! i just wanted to try and make it safe as posiable .

[flippy1974]

If you use a solid plate for front or rear of the block you will compound whatever forces you chassis back feeds into the block. The engine will torque over to the right but with no more force than the torque output of the engine.

It is normal for a high power v8 engine to use up #2 and #4 mains because of the crankshaft design. A flat or 180* firing crank doesn't do this.

Your bottom block filler is a waste of time ( or even a determent) for any purpose than to plug the coolant jacket in case the block was ground thru for rod clearance.

Block filler needs to be formulated so as to have exactly the same expansion rate as your block and if used at all should be at the top of the water jacket to support the cylinder walls where the most heat and pressure are.

Unibody---doesn't twist ??? now that is a laugh
it was done for clearance to make shure he didnt go threw will cuting on the block for the 383 stuff .i didnt want it filled all the way up because it is a street car i have drove this car from ohio to tampa florida when i still had the od tranny in it and the motor was the same as it is now .

[flippy1974]

hmmm, bad tuneups kill bearings ...period!

don't waste your money on the girdles....why do i say this, because i haven't seen a need for them. they certainly aren't cheap.

just my .02
well as far as tunes i have the best in the business aka bluecat . only the best for my turd .as far as cheap i dont like giong that way it allways cost more in the long run .i dont care to spend it if it will help .

[8SEC6SPD]

well as far as tunes i have the best in the business aka bluecat . only the best for my turd .as far as cheap i dont like giong that way it allways cost more in the long run .i dont care to spend it if it will help .

hmm, i don't take short cuts as well, and no evidence that it is required.

3600# @ 155+ mph that says enuff....i guess.:embarassed:

oh well then i have the best engine builder in the business, lol!!! and i tune my own shit, but i really suck! :laugh:

[flippy1974]

hmm, i don't take short cuts as well, and no evidence that it is required.

3600# @ 155+ mph that says enuff....i guess.:embarassed:

oh well then i have the best engine builder in the business, lol!!! and i tune my own shit, but i really suck! :laugh:
yes that is very impressive ! what kind of setup do u have ? what kind of power do u make to the wheel ?

[8SEC6SPD]

i have provided my .02, i am outta here!

[jakesz28]

Taner is right about tuneups killing bearings. If you’re hitting it with 350 hp shot what are you doing for individual cylinder control? It is not uncommon for the heavy hitters to pull a little more timing in certain cylinders to make a combo live. What ignition box are you running?

[Jerry Clayton]

The number 4 main takes more punishment because cylinders 5 and 7 fire consectively

[96lt1m6]

post 23 and 25
should have been enough!!!!!!

[flippy1974]

Taner is right about tuneups killing bearings. If you’re hitting it with 350 hp shot what are you doing for individual cylinder control? It is not uncommon for the heavy hitters to pull a little more timing in certain cylinders to make a combo live. What ignition box are you running?
well i have a 6al and msd timming control .i usally take 8 deg out of it when i spray .

[flippy1974]

i have provided my .02, i am outta here!
man come back ! i need your guys imput . the best of the best of the lt1 world helping me how cool !
i mean all these 9s cars helping me what could be better !

[flippy1974]

post 23 and 25
should have been enough!!!!!!
yea he made me fell alittle better about it , but wish he would stay around .

[Tony Shepherd]

We can't give all our secrets out! LOL!

Just for the record I do not run a motor plate. I run solid motor mounts. No oil valley girdle or main girdle for me.

My block is half filled, 4 bolt main splayed, and the deck is plugged.

[flippy1974]

well since i have all these fast cars helping this is what im going to have this year , see what u think .
383 eagle crank , h beam rods , srp pistons , h race bearings , spayed capped ,hard blocked , kooks headers 1 3/4 -1 7/8 steped with 3 1/2 colector ,
i got this coming to put on the motor

TrickFlow 215cc LT1 CNC'ed ProSeries SR Competition Head:
TFS-3042B010 Bare A-356-T61 Aluminum LT1 Heads
PSI 1226 Valve Springs with Xceldyne LtWt Ti-17 Retainer & Lock + Hardened/ Machined CrMoly
Locators (These are Cup Quality Components)
Competition Plus 21-4N Stainless Valves 2.08I/1.60E with HP Metal Clad Viton Seals
100% CNC'ed Intake/ Exhaust Runners & Chambers
Newen CNC'ed F1 Quality Valve Job (<3 microns TIR)
Bronze Guides Hand Honed to Competition Clearances & Tolerances
Deck is PCD Milled to Insure Flatness/Finish & Achieve Desired Chamber Volume (58cc - 62cc)
Pushrod Holes are Re-Machined (Additional Clearance for Higher Ratio Rockers & .375 Dia PR is
Required)

Ai ProSeries Solid Roller VT & Cam Kit:
Jesel KSS-336060 Sportsman Shaft Mount Rocker System
Morel 4843 UltraPro HIPPO LT1 Solid Lifters w/TieBar +.300
Ai One Piece .375 Dia Hardened 4130CM Pushrods .080 Wall
Induction Hardened 8620 Steel Core SR Camshaft w/Everwear Premium Gear (Compatible with all types
of oil pump gears)

ACCEL ProRam 1550cfm FI Intake Package:
ACC-74139 DFI ProRam Intake w/Fuel Rails
ACC-74202S2 1550cfm 4150 Series Flange Billet Throttle Body
Machining for Conversion to LT1 Head Bolt Pattern

2 COM-C5645-027 4.040 Bore .027TK LT1 Gasket H1656027S
1 FP1284 LT1 Intake Gasket Set
then im putting in a vortec disibuter , ls1 computer
and i have 2 foger nozzels first stage 150-200 sec stage 200-250 .

going threw A turbo 400 with brake and yank ss 3300 converter

home built 12 bolt rear with 3:90 gear

what do u all think .

[flippy1974]

We can't give all our secrets out! LOL!

Just for the record I do not run a motor plate. I run solid motor mounts. No oil valley girdle or main girdle for me.

My block is half filled, 4 bolt main splayed, and the deck is plugged.
thanks for the info !

[Tony Shepherd]

The first problem I see is the SRP pistons. Anything over a 200 shot and they will melt away.:shame:

[flippy1974]

The first problem I see is the SRP pistons. Anything over a 200 shot and they will melt away.:shame:
the pistons are 5 years old and still look brand new ( even with a trip from ohio to tampa Florida spark knocking all the way down and back but thats another story ), i havent had any problem with them and i had planed on going back with them . what do u all run ?

[96lt1m6]

The first problem I see is the SRP pistons. Anything over a 200 shot and they will melt away.:shame:


the pistons are 5 years old and still look brand new ( even with a trip from ohio to tampa Florida spark knocking all the way down and back but thats another story ), i havent had any problem with them and i had planed on going back with them . what do u all run ?

your pistons looking good after 5 years has nothng to do with how durable they will be with a large shot, Tony pointed this out! you pretty much defended them.
i would also look closely at the material that crank is made of...is it cast steel,forged steel 4340 or 5140?
what type of rod is in there?
you need a 4340crank and as far as pistons JE,Ross,Diamond etc.a better choice for a copious amount of nitrous.

[96lt1m6]

Big thing to remember here, there are a few that have been there and done that! knowing that, when one asks for advice and experienced advise is given and the recipiant seems to either doubt or sheds negative light upon a statement based on their experience it is almost an insult. There are many guys out there with a butt load of cash and have slow or broken cars......
I have known Taner now for 4 years,Tony about the same these two help soooo many people and those that listen seem to excel...........

[flippy1974]

your pistons looking good after 5 years has nothng to do with how durable they will be with a large shot, Tony pointed this out! you pretty much defended them.
i would also look closely at the material that crank is made of...is it cast steel,forged steel 4340 or 5140?
what type of rod is in there?
you need a 4340crank and as far as pistons JE,Ross,Diamond etc.a better choice for a copious amount of nitrous.
the crank is a eagle 4340 , h beam rods , but i have been spraying a 350 shot on the for 2 years and a couple times at full timming because i forgot to retard the timming ( because im a retard and get in to big of a hurry at the track) i guess i need to look at the JE,Ross,Diamond pistons if u guys dont like the srp that much .this is why i thought these pistons were good was i had a head fail last year at the end of the season is the reason i was upgrading , it blow a hole plum threw the cummbustion chamber and threw the watre jaket to the outside of the head , and destoryed the plug and the pistons still look like new ! so that why i kinda defended the srps .

[flippy1974]

Big thing to remember here, there are a few that have been there and done that! knowing that, when one asks for advice and experienced advise is given and the recipiant seems to either doubt or sheds negative light upon a statement based on their experience it is almost an insult. There are many guys out there with a butt load of cash and have slow or broken cars......
I have known Taner now for 4 years,Tony about the same these two help soooo many people and those that listen seem to excel...........
if i insulted anybody im sorry . i was just ring to under stand what they were saying and trying to get out there what i was doing .i dont have a but load of cash ,its been 5 years for me to get the money for these heads , ive been running stock heads with stock size valves since day 1 . and i have no clue how to tune a car so thats why i have to have it done , i very computer illiteret . i think thats why i have trouble understanding and people understaning what im saying . im just a voed gradulate and a factory worker ( grunt) tring to have a half fast car .

[flippy1974]

here is some pics of the head that the n/x took out .
http://i227.photobucket.com/albums/dd57/flippy1974z28/camaro/motor/th_100_2885.jpg (http://s227.photobucket.com/albums/dd57/flippy1974z28/camaro/motor/?action=view&current=100_2885.jpg)
http://i227.photobucket.com/albums/dd57/flippy1974z28/camaro/motor/th_100_2886.jpg (http://s227.photobucket.com/albums/dd57/flippy1974z28/camaro/motor/?action=view&current=100_2886.jpg)
http://i227.photobucket.com/albums/dd57/flippy1974z28/camaro/motor/th_100_2887.jpg (http://s227.photobucket.com/albums/dd57/flippy1974z28/camaro/motor/?action=view&current=100_2887.jpg)
http://i227.photobucket.com/albums/dd57/flippy1974z28/camaro/motor/th_100_2889.jpg (http://s227.photobucket.com/albums/dd57/flippy1974z28/camaro/motor/?action=view&current=100_2889.jpg)

[Tony Shepherd]

No insult taken here.

Reseach the material of SRP pistons. Something about silicon based metal.

They hold up well to N/A applications but with butt loads of cylinder pressures and high temps the material breaks down.

I have an SRP piston from years ago. It is a paper weight right here on my desk.:D

You need to step up to a JE or Wiseco custom nitrous piston.

[flippy1974]

No insult taken here.

Reseach the material of SRP pistons. Something about silicon based metal.

They hold up well to N/A applications but with butt loads of cylinder pressures and high temps the material breaks down.

I have an SRP piston from years ago. It is a paper weight right here on my desk.:D

You need to step up to a JE or Wiseco custom nitrous piston.
yea im going to talk to my motor builder about them this weekend , thanks for the help .

[Z8's]

I have srp's in my blower engine.:shame: "I have Diamond in my Turbo engine:secret:
Your tune is very important.:whistle:

[jakesz28]

Tuning a car to run good on motor and have good drivablity has little effect to what heavy nitrous users call their tune. I heavy nitrous user will have to shut the car down and read the plugs. Fuel and timing will effect what you can get away with. I can't beleave it lived with a 350 shot and only 8* timing pulled.

Was that with the LT1 intake and what plate were you using. What size jets did you have in it? And what did your fuel system?


I'm not running any girdles and this is a new combo that went together later in the season last year. The shop that built the short block (knowing it was going to get 350hp of spray) said not to use any block filler. The second shop that was going to tear it down of the winter said not to use block filler. I'm running wisco pitons.

[flippy1974]

Tuning a car to run good on motor and have good drivablity has little effect to what heavy nitrous users call their tune. I heavy nitrous user will have to shut the car down and read the plugs. Fuel and timing will effect what you can get away with. I can't beleave it lived with a 350 shot and only 8* timing pulled.

Was that with the LT1 intake and what plate were you using. What size jets did you have in it? And what did your fuel system?


I'm not running any girdles and this is a new combo that went together later in the season last year. The shop that built the short block (knowing it was going to get 350hp of spray) said not to use any block filler. The second shop that was going to tear it down of the winter said not to use block filler. I'm running wisco pitons.
yes that was with the stock 93 intake ported and polished , i was using 2 shark nozzels . they were the jet they recomended . all i have for a fuel system is a 255 in the tank . i want to do 2 walbors this year and 6 an line . the car was sprayed on the dyno to 250 shot and a/f was great and plugs looked good , was going for the 350 shot and the dam opti went out so i didnt get to see a/f on that but the plugs looked good after a run .the pass the head let loose i forgot and only took 5 deg out and only have at the best a 50/50 mix of race fuel so the head was all my fualt for being dumb .