What does it take to hit 7,500 RPM

[vetteeatr]

Ok guys ive heard you need forged internals for this type of RPM but why? Im looking for something like 450-500 at the crank

Tell me what you think of this combo. Also your own ideas would be great. Supposedly the victor Jr. combo puts out over 500 horses so this i was hoping would be near the same due to lower compression...


AFR 205 race heads
victor 5.0 intake
36lbs injectors
1 5/8 full length headers(Do i need 3/4")
Need help on the cam selection
Run around 10.5-11:1 comp
A really well balanced light driveshaft linked to a T-5

I figure i wanna peak at somewhere from 7,000-7,500 RPM
Am i gonna be able to keep this streetable or did i just cross the line?


What do you think the numbers for this would be?

Im looking to build a streetable classic fastback weighign in at aournd 2100-2300 lbs and make more of a corner carver. Due to Light weight in theory would make this a 10 second car

By replacing the whole front end wiht a fiberglass unit how much weight do you think i would shave off factory weight by the way?

[Coupe50h]

I say your t-5 will live a short life.

That, you would need a custom cam for sure, 500hp at the crank would need over .600 lift, 11.5 cmprso,n and solid lifters, but hopefully someone else can share some opinion.

My friend turns over 6900-7k with a hyd roller lifter b-cam, and forged internals, i do not see the need for forged pistons unless your spraying.

[vetteeatr]

so are you saying i dont need a forged crankshaft and rods?

If i was to add like a 100 HP shot of nitrous do you think the stock internals will take it. This will probally barely happen

[bottlebaby91]

The stock internals are should be fine for a 100 shot. The stock pistons are forged in an 88 5.0 motor.

[ultraflo]

What cubic inch, btw???

I shifted my stock block 306 at 7k and crossed the 1/4 mi at 7200rpm with a combo similar, generally speaking, to what you've listed....

Ported Edel. RPM 6025's
victor 5.0 intake (with two 1" spacers) ...hence the hood
36lb. injectors (would've been fine w/ 30's)
Bassani 1 5/8" - 1 3/4" stepped long tubes
custom ground Ultradyne hyd. roller cam (for a combo different than what I ended up with)
10.5:1 JE forged nitrous pistons (polished the combustion chambers, so figure a bit less than 10.5)
Jerico DR4 (the T5 is a crap shoot btw) w/ SVO alum. driveshaft

With a Nitrous Express single nozzle EFI wet kit jetted for 200hp, I went 10.0's @ 130+ at just a bit over 3100lbs.

I wouldn't recommend using a stock 2 bolt main block (unless you can't fork over the dough for an R302 or Dart block) ...after well over 100 1/4mi. passes and daily driven street duty from '99 to '01 (motor was fresh in summer of '99) the block split on Oct. 20th of this year after 67 passes spraying 200hp.

I estimate the HP levels of my old combo to be anywhere from 575-600hp at the rear tires.

Why forged internals, you ask??? ...in short, strength and reliability!

You can spin a hyd roller cam to 8000rpms with the proper valvetrain/components... think titanium valves, locks, retainers, and a very light weight rotating assembly.

LOL, my previous combo would've been good for some 9.0's or quicker in a 2100lb. car

Also, I sprayed 150hp on the stock '93 short block in '98 until I broke a valve (stock).... so, yeah, you can spray 100hp. Tune conservatively and do your homework before using nitrous... mistakes can be costly if you're not careful.

Not sure how much weight you'd drop with a 'glass front end

Laters,
-Ryan

[vetteeatr]

man thats scary at how close i want that exact combo. its a 306 as well.

I understand about forged internals but i didint really wanna spend big bucks on this set-up. I will use my intake and basicalyl everything later on on a 351 was the plan which i will make a beast. I was trying ot keep the power low enoguh so i didnt have to have forged everything.

So if lets say i keep the power around 500 horses at the crank will i really need all those forged pieces.....

I allready have some pistons and block freshly bored so im trying ot work with this for the time being.

I was thinking that the stock block could handle something like 600 horses??? But i beleive forged componenets come in aroudn 450-500???


On motor what do yu think you were putting to the rear wheels? 400?

[ultraflo]

Originally posted by vetteeatr
I was thinking that the stock block could handle something like 600 horses??? But i beleive forged componenets come in aroudn 450-500???

On motor what do yu think you were putting to the rear wheels? 400?

2002 combo ...check this out

The stock block isn't a sound investment for a 600+ hp application and is not recommended.... but, you do what you gotta do. At the very least, get a girdle and have the mains align honed once you bolt it up, if you haven't already.

575-600hp at the wheels minus a 200hp shot = 375-400hp

What type of computer setup do you plan on utilizing to get past the factory rev limit?

500hp at the crank is a far reach for what you've offered in terms of information regarding your plans. You'll be looking at 400+ at the crank ...with a good tune-up.

[vetteeatr]

well basicalyl i had a car that was kinda equipped with this and that but i decided to go stupid over a girl and plowed into a new caddillac...... Ugly

Im not exactly sure on everythign ut it has an MSD box wiht rev limiter at 7200 and i know i can go over the stock limiter never realyl went ot 7200 before though. I was just gonna have a custom chip burnt after i convert to mass air.

how is it that you combo cranked out so many more horses then mine would?

I would have a custom cam ground for me as well.

Also forgot the valvetrain will be upgraded to lighter components.

Could I run 11:1 compression the highest octane fuel available at gas stations? or is that pushing it a little to far?

500 horses at the crank seems not to far form ebign realistic as i thought victor jr parts outta the box puts out over 500 horses??? compression is alto higher but does that extra 2.5 points really make that much diffrence?

[vetteeatr]

well basicalyl i had a car that was kinda equipped with this and that but i decided to go stupid over a girl and plowed into a new caddillac...... Ugly

Im not exactly sure on everythign ut it has an MSD box wiht rev limiter at 7200 and i know i can go over the stock limiter never realyl went ot 7200 before though. I was just gonna have a custom chip burnt after i convert to mass air.

how is it that you combo cranked out so many more horses then mine would?

I would have a custom cam ground for me as well.

Also forgot the valvetrain will be upgraded to lighter components.

Could I run 11:1 compression the highest octane fuel available at gas stations? or is that pushing it a little to far?

500 horses at the crank seems not to far form ebign realistic as i thought victor jr parts outta the box puts out over 500 horses??? compression is alto higher but does that extra 2.5 points really make that much diffrence?

[Coupe50h]

11.1 compression and aluminum heads, maybe not too bad, id back off the timing and drive it on a cool day, with the minimum of 100-103 octane fuel, just add some vp to 93 to be safe. wot runs would be 115 octane, especially with nitrous, just my opinion though.

Also, when he said the crank and internals would have to be lightened, he means really lightened, as in a custom forged crank that would have to be cut on a bit, and rebalanced, talkin$$$$$

500 at the crank would need to be achieved with a power adder, if it's still gonna be streetable, now if you get into strokers you can push 500 n/a no problem.
302/306 is gonna have a rough idle, and high compression, maybe a weekend car for me

Here is my opinionated recipe for 500 crank hp 306, and reliable:
d.s.s 306 pro bullet, msd, stage 3 trickflows, longtubes, holley intake, 70mm tb, f-cam, 42# injectors, 8lb of s-trim boost.
I have seen a combo similair to this, pushing 480 to the wheels with stock rev limit and computer. also rode in it, and im hooked on that power

[red82gt]

The Vic Jr. parts flow enough air to make 500hp out of the box, you can't just bolt these onto a 5.0 shortblock and get 500hp. With a very radical 306 you'd be lucky to see a n/a 500hp. I think it's gonna take more than 11:1 compression to do it too, more like 12.5:1 or more. At that point, forget streetability.
Also, you said you don't want to spend a lot of money but you want a 10 second n/a car that's streetable, if it was that easy, don't you think everyone here would have one?
I've got my doubts about getting the car down to 2100-2300 lbs without ending up with just a skeleton.
Don't want to piss on your cornflakes but I don't think you'll reach this goal.

[vetteeatr]

Oh god no not the cornflakes......

Okay well what about 450 HP?

I think im gonan change it up just a tad and lower my RPM's to like low 7's when i shift.

Stock fastbacks weighed in at like 2658 or somethign aroudn tehre is it realyl gonan be that hard to drop 300 pounds?

Aluminum heads -50lbs
Aluminum Driveshaft - some little bit
Fiberglass Body? I was kinda hopping the fornt end woudl shave at least 100 lbs off and i figure the res of the body maybe 200?
Bumpers woudl be fiberglass as well whcih i imagnie woudl be a pretty big save.

approximately 2300 with that... Also wont have air and a few other thing i think its actaully pretty realistic.. correct me if im wrong though as im just looking at numbers and guessing.

I dont really know i kinda plan to upgrade as i have money and drive while i upgrade...


more then likely i woudl have fiberglass doors as well...

I htink the whole fiberglass body and doors and all is like right around 100 lbs at the most and thats for the stronger one...

[Shogun]

Dude, a N/A small cube motor i.e. sub 310 cubes, 400 HP is a magic number, and still have enough manerism to perform as a daily driver. Especially, if you want a low buck pump gas burning machine. Anything over about 350 HP you really need upgrade your driveline beyond your motor. Unless of course your made of money. . Oh, and hyd roller lifters don't work to well much above 6G's so plan on solids, and checking lash at every oil change, provided you don't race to much. just my .02

[ultraflo]

Originally posted by Shogun
Oh, and hyd roller lifters don't work too well much above 6G's

They work just fine past 6000rpms with the correct valve springs and camshaft ...with titanium valves, locks, and retainers you can get as much as 8000rpms with hyd rollers these days.

Also, you can modify the hyd rollers to act like a solid, while maintaining enough plunger travel to be deemed legal in the NHRA stock classes, where these modified hyd rollers are quite common. And, the Renegade boys are spinning 7500+ rpms with hyd roller lifters...

I run a set of SRP modified hyd rollers that work great at the 7000rpm shift points on my previous setup... I will either be shifting at 7k or just over on the next combo as well with, you guessed it, hyd roller lifters.

[Shogun]

OK, ultraflo, Yes given the right conditions, modded hyd rollers can kick butt. I'm talkin a daily driven street application. As for Titanium parts, Well, I glad you can afford them.

[srv1]

Originally posted by ultraflo
They work just fine past 6000rpms with the correct valve springs and camshaft ...with titanium valves, locks, and retainers you can get as much as 8000rpms with hyd rollers these days.

Also, you can modify the hyd rollers to act like a solid, while maintaining enough plunger travel to be deemed legal in the NHRA stock classes, where these modified hyd rollers are quite common. And, the Renegade boys are spinning 7500+ rpms with hyd roller lifters...

I run a set of SRP modified hyd rollers that work great at the 7000rpm shift points on my previous setup... I will either be shifting at 7k or just over on the next combo as well with, you guessed it, hyd roller lifters.

not to get off the subject(i think), but no one every talked about lubrication for 7000 RPM's. what pan? what scraper? what girdle? what oil pump? HVLP? what type of oil pump? this i think is VERY important also i want to build mine to run 6500 MAX rpm's safely. so basically it is a question for me and vettereatr and anyone else who doesnt know.

[ultraflo]

Originally posted by srv1
not to get off the subject(i think), but no one every talked about lubrication for 7000 RPM's. what pan? what scraper? what girdle? what oil pump? HVLP? what type of oil pump? this i think is VERY important also i want to build mine to run 6500 MAX rpm's safely. so basically it is a question for me and vettereatr and anyone else who doesnt know.

I use a Moroso T-sump pan (I would've destroyed a deep sump pan when I did the wheelstand in late Oct. ), which has a sort of basic/universal scraper incorporated into it. In other words, it doesn't extend out to fit around the crank throws and main caps like a true crank scraper does. It's better than nothing at all, I guess.

DSS/SVO girdle (don't forget to align hone the block once installing the girdle for those who aren't/weren't aware). I've read where the alum. girdles do a better job of dampening harmonics, but I cannot personnally attest to the claim, just thought I'd throw that out there for discussion. It's a nice piece and is actually for sale (girdle and studs) if anyone is interested.

The topic of oil pumps is one I'd like to know more about... I used a Mellings HV oil pump on my last combo. At this point, I am unsure which route I will go as far as HV or Std.Vol. The Std. pump takes less HP to run, however, the added benefit of a the HV pump seems to good to pass up. That, and the Moroso catalog calls for the HVHP pump with the T-sump pan. I need to do some more homework on which pump I am going to end up using on the R-306 combo.

In theory, you only need 10psi/1000rpms... if that's the case, when I split my stock block and had 20psi at idle, I was good to go I had 80psi at idle when the motor was fresh, and after 2 1/2yrs. of beating on it, it ended up around 65psi at idle a few months before the block let go. I tore the motor down thinking the bearings were done, the looked like new and I even plasti-guaged the rods and mains and the clearances where still tight. Put it all back together and gave 'er hell. I think the outstanding bite the M/T's offer over the Goodyears played a role in the block letting go, since the Mickey's wouldn't spin off the line All that energy was transferred up through the drivetrain/motor and the weak link (stock block) let go at over 600hp being put down to the pavement (dropped .2 off my ET just from a tire swap)

That's it, in a nutshell... Hopefully my ramblings can offer some insight into the next combo anyone may be getting ready to put together. I'm learning as I go, and don't claim to be a serious engine builder... the last motor I ran was assembled by me, and I was amazed that it lasted as long as it did. "Props" to the guy that did all of the machine work for me... I'll be visiting him again soon, once I finish preping the R-block.

[ultraflo]

Originally posted by Shogun
OK, ultraflo, Yes given the right conditions, modded hyd rollers can kick butt. I'm talkin a daily driven street application. As for Titanium parts, Well, I glad you can afford them.

LOL, I wish I could afford some titanium valves. I'd be setting my next combo up to do 8k if that were the case, but it's not, sadly.

It was a major ordeal just to get my paws on some Ti. locks and retainers... That's about as good as it gets at this point in time, for me. I run Manley race-flo valves with undercut stems along with the 10* Ti. locks/retainers.

Oh, and SRP is Sherman Racing Products... not the SRP that makes/sells pistons. Didn't want to confuse anyone who might look into a set of modified hyd rollers from these guys. They can either rebuild a set you send them for around $200 or send you a new modified set for $350, I believe (last I checked).

-Ryan