Thinking of building a nitrous 318 to run a limited heads up class at my local track. If I stay below 335 cu in. I can still run a single plane intake and a single plate system with up to a 65 pill. I think I'm restricted to iron heads too so I can get a weight break. All that being said, do you think it is possible to build a 318 or maybe an offset ground crank in a 318 or 273 block with n20 to run mid 6's in the eight in a 2900# car? I'd be running a glide and an 8 3/4 and the car still has to be leaf sprung with a 26x10 tire. It's a tall order but so far I haven't seen any Mopars in the class

YES..
a .65 pill will give you a solid 1 second to 1.3 seconds faster than N/A..
i think you should be able to run a 318" mid 7 sec 1/8th mile on carb..then go faster on the no2

are you limited to camshaft?
cheapst

It should be pretty easy, It would be easier if you tossed that glide and put a 904 in it. You could run less gear and put those 26" tires to work. You'll need about 550 HP to get mid 6's

I was thinking about commenting on the p/g trans also. but didnt know enough about how they do on smallblocks low torque.. to form an opinion.

I would say youll need the 1st gear.It would be a benifit. it will recover better..

I ran cheapstreet class in 03-04 alot of the chevies ran P/Glides..My car would hammer them out of the gate..Then when ever the Drivers would get together after hours in the pits to explain set ups..
fwiw
they always seem to hold back or be ambiguous on the nitrous tune ups. I always asked lots of questions..but guys thought I was sand bagging in qualifying cause it would fender them..then they would go buy me on the big end.
they thought i had more than i actually had?
And were reluctant to really give me specific info.
It was hard to figure out the smaller shot of no2 back then. These guys where getting it done..For the most part guys would help each other out..
I never seem'd to get the answer i was looking for? I had to do it the hard way.
Ill give you what i can remember..
first off get the most effecient pluming done on the lines and fittings..
I sent my stuff to Monte..he has some fittings that dont restrict the I.D. of the lines.
also dont change the spray bar plate that comes with the kit..unless you get a plate built.
We tried a 64hole? (more holes than the kit)plate from the beginning and it didnt work properly...I didnt find this out until i put the smaller 32hole? plate on..and it picked up.
Alot of tune up issue went away after doing this.
distribution is key.
IMHO send your intake and plate set up to Monte Smith , he will drill the holes in the bars and aim them at the intake runners for your intake.
and he will give you a jet map..He puts it all on paper..your tune will be exactly where you need it, from the get go..takes the guess work out of it...Best advice i could give on that...(it took me a yr to figure this out..he got me an 8th place points finish for that year.)
And run the bigger bottle it is more consistant as you go rounds.
We found those 10" tires only like around 30 or so passes..then the 60ft started to fall off.
New slicks was always good for afew tenths..
Camshaft..I found running a cam that is designed to give you the most power with out no2..Is the way to go..then spray it.
we started adding duration..later and picked up some..but the best cams were the ones that make the best power n/a...
a trans brake picked up my 60fts by alot..
a high gear ignition retard also picked up the mph.
If your building from a clean slate..go after the most cubes you can for your class..to start with.
chepast

Are you restricted to STOCK iron heads or just ANY iron head? Iron W2's come to mind if you can find some. If you can get/use them, cam it accordingly and spin the wee out of it. One would think with small cubes/torque, the 904 would have an advantage over the Glide but with converter technology where it is, maybe not.

Kevin

I'll have to look into w-2's. I don't know how picky this class gets on the iron heads, but I expect they would frown on the offset rocker setup but idk. I just want to keep the glide for weight and cost. I just refuse to pay the prices for good 904 stuff that won't slip after 10 passes. The 904 I have in my turbo car now was a fresh rebuild by a local shop known to be good at building a chrysler trans and only lasted about 200 miles before it started to slip under boost. He even added clutches and steels and it has new bands. I took it back and he adjusted the bands and checked the line pressure and still has the same problem. I've never had any luck with 904's

I'm just throwing this idea around because I want to get back into racing on a regular basis and my turbo car is too slow for the other classes in PTRA lol

If the rules just say 'Must use iron heads" you should be golden. If it says "stock iron head" nope. Any valve train specific rules? If not, offset rockers should be OK.

How heavy/fast is your turbo car? Unless it is stupid fast/heavy, 30 laps seems awful short for durability for a well built 904.

Just re-read your last post. I think you need a new trans guy. On the street IMHO the tires should slip before the trans ever does.

Kevin

If you can't use w2 heads run a set of RHS LA style heads. I would not start asking around, I would look in the rule book and if there is no mention of stock style or offset rockers or stock head castings I would just use the W2, if you start asking there may be a rule that magically apears and outlaws a w2. Same goes with the RHS but it does not use offset rockers. Un touched RHS heasd you can easily make 450 hp and full ported could get close to 600.

If you can't run an aftermarket block find an early 318 block from around 68-71 get it sonic checked and use it, lots of them can easily handle .090+ over bores, just pick the bore that gets you closest to your CUI limit, .090 over = 333 CUI. If you offset grind the crank .020 you will be at 334.75 cubic inch. With the big grooves on the side of the journal on a stock forged crank that will still be the weak point and the .020 grind will not hurt the integrity of the crank at all. Run the lightest pistons you can find that can handle a little N20 because it is gonna want to rev real high, depending on witch heads you end up with RHS or un-ported W2 I would run a SCAT I beam if you can port them it means more RPM and you should step up to a better rod. I would also run a behive spring and 8mm valve stems to keep everything light for the high RPM ride. If I was closer I would give you a hand building it.

The 904 with standard gear sets will work good with this motor because it will be tq limited and function best in a narrow RPM range, however in just 1/8th mile racing it may not make a big differance VS a glide, in 1/4 mile it would be a big differance. No reason a 904 can't handle that power for quite a while if built right, I would find a new trans builder if I was you, again too bad I don't live closer

Ported poly heads actually flow prett damn good.
cheapst

Yeah It's possible, I wouldn't out trick yourself on the shortblock just a stock stroke 318 with a steel crank, H beams and a good piston. I would try to get more tire under it- at least 28-29" tall and run a 4.56 or 4.88 and I wouldn't run a 'glide- run a th350 with a 8" converter if you are dead set against torqueflites.

I know of a 318 A body with .88's 904 with an 8" and 29" slicks that went 7.80's with 1.88 valve 360 heads,.441" cam performer intake and a TQ, 7.60's with a strip dominator, 7.20's with a strip dominator, EQ magnums with 2.02's and a MP .528 with 1.6 rockers. It ran really well for what it is, it would run mid 1.5 60's leaving off the footbrake at 4k, shift at 6,400 and let it run out the back door, it usually ran 90-91mph but I've seen 93mph once when we had some really good air in Jan.

I'm limited to a 26" tire for the class unfortunately I *might* stay with a 904 if my engine build ended up cheap enough to allow the funds to build the trans. cheapst, you said poly heads flow good ported...do you think they would be good enough to support this motor? I guess headers might be a problem though, the only sets I've seen are for b bodies and they are pricey.

This whole build revolves around me finding a car to put it all in. I really hate to tear my turbo car apart to build this because it is so much fun on the street and runs on pump gas lol

well that changes everything...

there are a few people that hotrod the poly motors..I know R,A,M was a proponent..

the heads are like a hemi ....I just was responding to the other poly comment.

your La heads will support it also...i would offset grind or bore your way to 334"
Trust me..do that the first time you build..
Its performance thats avail..dont leave it on the paper..

it would be like using a .63 no2 pill.. when a .65 no2 pill is allowed...

most likely the chassis will be an A-body..

chepast

The poly heads don't flow as much as even an X head, 915 or 308 and no chance of keeping up with an RHS or W2 not to mention they are heavier and harder to fit.

I have access to a poly motor maybe for free...I'll see if I can pick it up for the block. It will definitely be in an A body. I've got my eye on a 67 dart locally but I'm unsure on what the price is going to be. I hope I can find a rust bucket and get away cheap The body will have cal-tracs/monos and a 8pt cage, maybe a 10 pt. depends on what I can afford when the time comes. I wanted to go with an Alterkation front end and glass hood/fenders but It has to be a minimum 3100lbs and if Its like my valiant it only weighs 3128 with me in it...and I'm 220lbs

dont worry about getting the car too light..
if you have to add weight its not a bad thing.
just add it over the back tires..

cheapst

The poly 318s had nice forged cranks in them and the good heads will bolt to a poly block. The one thing with any old block back then is rust in the water jackets makeing the walls thinner, they may have started out thick but become thinner over the last 50 years, always sonic check when going that drastic.