MRL Performance NHRA IS/A 360

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MRL Performance

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Man what a challenge this little 360 was. This is a IS/A NHRA engine we just got done with for Locomotion. Rules rules and more rules. A challenge we were up for. In the end we destroyed a set of junk heads looking for the best valve job. I invented on that blew me away. There is no porting of any kind allowed, nothing at all. Im not going to get into all the rules, so you can look them up on NHRA's web site for IS/A, Mopar 360 circa 1978.

You guys have been asking for some LOW compression HP builds, well here you go. Some info on this engine

360 block prepped and ready to build, Major block fill!
8.5 to 1 compression pump gas premium
Bone stock 596 Smog heads, crossover NOT filled but blocked
Bone stock 360 dual plane intake, egr blocked off
1.88/1.60 valves
Very trick and secret valve job sorry but i'll never tell!
Harland Sharp rockers
Milodon stock looking replacement pan
Special Comp flat tappet cam(customer supplied) sorry no specs here either.
Trick ceramic short travel hydraulic lifters
K1 rods, CP pistons with trick 1.2mm rings in 5/64 groove. That was fun LOL

This engine pulled hard to 6500rpm peaking at 6000rpm.

I know some of you know how hard it is to make power with these types of engines. I have so many hours into the heads I lost count. But it did pay off in the end.

Any guesses on power??
 

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380-400..really curious on the peak power point,with the lower compression combo.
 
The suspense is killing me! Lol 425 is my guess.
 
hangn0ut said:
Takes some power to run competitive times. 495-505 HP.
Click to expand...

The IS/A class has to run 12.00-12.50. With his race weight he needs 435HP to run a 12.00. There is no way this combo will make 505HP without cheating and heavily at that. I know a lot of people do and it costs them a small fortune, there is absolutely no cheating anywhere on this engine. Heck I even errored on the side of caution on everything.

You guys are real close. It made 420/430 and was still on the rich side. Ill bet after some fine tuning when its in the car he will be running 12.00 all day long.
 
Hey Mike, tell Myron that it mysteriously disappeared. I'll be up to pick it up shortly. :D

Nice number.
 
MRL Performance said:
The IS/A class has to run 12.00-12.50. With his race weight he needs 435HP to run a 12.00. There is no way this combo will make 505HP without cheating and heavily at that. I know a lot of people do and it costs them a small fortune, there is absolutely no cheating anywhere on this engine. Heck I even errored on the side of caution on everything.

You guys are real close. It made 420/430 and was still on the rich side. Ill bet after some fine tuning when its in the car he will be running 12.00 all day long.
Click to expand...

That is amazing! That must be a super light rotating assy and some kinda cam to go along with the valves!
 
What carb and size headers/
Tested with exhaust pipe and mufflers?
 
nhra class index for I/SA is 12.30...that is the minimum that you can dial....and if you can not run WELL under the index...you will get killed in class run offs...or any heads up races during eliminations..plus some places like Indy you will need to run 7 tenths under the index just to qualify....

stocker 360 will require thermoquad in nhra...

welcome to nhra stock elimination.....
 
70aarcuda said:
nhra class index for I/SA is 12.30...that is the minimum that you can dial....and if you can not run WELL under the index...you will get killed in class run offs...or any heads up races during eliminations..plus some places like Indy you will need to run 7 tenths under the index just to qualify....

stocker 360 will require thermoquad in nhra...

welcome to nhra stock elimination.....
Click to expand...


Yes ... Being competitive is super important when it comes to heads up races..other then that its just a bracket race.. Our H/SA Cuda runs 11.50s on a 12.15 index .. And that's still not that competitive at all.. There are H/SA 80s Camaros running 10.90s-11.30s
 
So it's class racing that has you running a min. of XX.xx
after that it's heads up?
 
I'd love to see the valves out of that one. ;) I'm betting there are multiple angles on both sides of the valve head.....
 
rumblefish360 said:
So it's class racing that has you running a min. of XX.xx
after that it's heads up?
Click to expand...

No... There are multiple different classes in Stock Eliminator.. H/SA G/SA F/SA and so on..

Each of those classes have a "index" witch is a number that you cant run slower than.

If the index is 12.15 then you want to run as far under the index as you can .. say 11.15 would be .90 under the index. - That is very good..

The way qualifying works is that the guy who runs most under there index is 1st.. That's why people who don't run much under cant qualify for INDY usually..

It is all just a bracket race where you dial in until you meet a guy in the same class as you .. say H/SA vs H/SA.. This means its a heads up race.. First one to the finish line wins..

Hope this explains it
 
the rotating parts have to weigh a certain amount!! no knife edged cranks, pistons and rods have a min weight they have to meet. stock crank is required. rules state, no lightning of components allowed. every thing has to be legal to pass a teardown!!!!!
 
rumblefish360 said:
So it's class racing that has you running a min. of XX.xx
after that it's heads up?
Click to expand...

you qualify base on your index...i/sa is 12.30...so 12.30 is the minimum you can dial in at...and say you can run 12.50...you dial is still the index of 12.30...
r
so have far you run under the index is what set the qualifying field compared to the other classes....you run 12 flat...you are 3 tenths under...and F/SA run 5 tenth under his index he is qualified higher on the ladder...and so on for the other class...you dont want to run 1.20 seconds under your index...you get hit with an automatic HP adjustment on monday...more weight added to the car....plus after a certain number of runs under 1 second under your index your combo get looked at...for more weight......It is a game..

my friends 68 barracuda is F/SA...and nhra tracks that 340 combo for all the passes made at national and divisional races to see if the HP factor is correct...if the average is getting close to that 1 second ...they will slow the car down to protect the HP rating of the engine.......It is a game...LOL

once eliminations begin...it is a bracket race...unless you run a car in your same class...then 1st one to the finish line wins...heads up race..

some national events have class run off....bragging rights to say you are the fastest car in that class on that day at that event.....you get a trophy....lol
usually the extra weight in the trunk comes out.. to get down to the minimum class weight....I believe he removed 120 lbs out of the weight box at the April nhra race in vegas cause 2nd round he had a head up race with another F/SA car...he also changed AVS carbs...one is faster then the other...drain the Sunoco gas and went to the VP gas.....alot of work to win one round..lol
 
MRL Performance said:
The IS/A class has to run 12.00-12.50. With his race weight he needs 435HP to run a 12.00. There is no way this combo will make 505HP without cheating and heavily at that. I know a lot of people do and it costs them a small fortune, there is absolutely no cheating anywhere on this engine. Heck I even errored on the side of caution on everything.

You guys are real close. It made 420/430 and was still on the rich side. Ill bet after some fine tuning when its in the car he will be running 12.00 all day long.
Click to expand...

hi, welcome to the real world of finding horse power within a boundary limits. legally too!!!
no throwing parts at it! congrats. stock eliminator is a thinking mans place.
 
dont mean to hijack the thread...but just giving some info on the wonderful world of stock..

earl qualified 38......... 11.237 12.06 -0.823

11.237 on a 12.06 index...at vegas and vegas indexes are adjusted for the elevation...


777 Earl Blake ****WINNER**** 0.002 11.186 116.96 F/SA Dial: 12.06 (+/-): -0.874
7158 Sante Grossi 0.005 11.203 117.15 F/SA Dial: 12.06 (+/-): -0.857

Any way..good luck and have fun...
 
MRL Performance said:
The IS/A class has to run 12.00-12.50. With his race weight he needs 435HP to run a 12.00. There is no way this combo will make 505HP without cheating and heavily at that. I know a lot of people do and it costs them a small fortune, there is absolutely no cheating anywhere on this engine. Heck I even errored on the side of caution on everything.

You guys are real close. It made 420/430 and was still on the rich side. Ill bet after some fine tuning when its in the car he will be running 12.00 all day long.
Click to expand...
That's some good power from a "stock" build .
 
We built it just like he wanted it, no cheating and the power is more than he expected(me as well). He got the skills to set up the car, so Im betting he will do very well.
 
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