Hey- I am currently building a 400 small block chevy motor for my 86 sport coupe. I got my block bored .30 over making it a 406, i am using 64 cc heads, comp cams 268 series cam(477/480 lift, 268/280 duration), edelbrock performer intake, edelbrock 750 cfm electric choke carb, all accel ignition, keith black signature series pistons with 30 cc dish for 5.7 rods, Gm powdered connecting rods, roller tip rockers, hedman headers, and a 3 inch cat back flowmaster american thunder exhaust, and a stock crankshaft. I am backing this with a T-5 tranny and 3.42 gears. I am looking for a rough estimate for Horsepower and Quarter mile time to expect, if anyone has desktop dyno and they could tell me a HP rating i would appreciate, or someone running a similar package
Thanks, Kevin

 

You might have a look at this months CarCraft...
406 shootout... In a Nova though...

1/4 times will largely depend on chassis, drive train,
rubber, driver issues...

 

the 406 will blow that T-5 to high hell on your first test drive, i would really look into upgrading it

 

thats what i was gonna say...look into a t-56 (6 speed)...or if you wanna go with a 4 speed a muncie or super t-10 should do ya fine.

 

Hey thanks for the info guys, but how would you suggest making it stronger, down the road i want to put in a t-56 but i dont have my money right now. I have read about guys on here that are using their t-5's with 450 horse power 383 strokers and say they have no problems, i am thinking it is all in how i drive it, as long as i dont go power shifting it i think it will be allright.

 

OK, here it is. I could only use the info you supplied. If you were more specific about the heads, that would help a lot. But this will give you a good idea of what you are looking at

It's gonna be a real torque monster! And a rocket ride with the HP coming on like gang-busters as the rpms increase

If you are using some nice heads, like Vortecs, that will have your 406 pushing a good solid 400 hp--you gotta like that :hail: :hail: :hail:

You should be pulling at least low 13s in the Quarter, once this is setup properly. I think 12s are almost a certainty, too. :rockon: :rockon:

 

the only thing i can suggest on that tranny is baby the hell out of it,dont do burnouts/go to the drag strip.

also get a really nice clutch,like a centerforce- other guys will probably know a little bit more specifics tho.

 

It increases case flex. There are 11second SC 4.6 cobras that have T5s.

 

I wouldnt bet on that. Look at my signature. Had this NON WC T5 for quite a while now... and yes I do race it every weekened.

 

one thing i would definately do is take those proform roller tip rockers and pitch em right in the trash cuz thats what they are. i had one fly apart on me one night at 70mph/3000rpm on the highway on my way to jegs. i got lucky it didn't shoot the pushrod through the hood....it got wedged between the lifter and the pushrod slot in the head.


and to the guy who desktop dyno'd that motor.....those numbers are going to be too high because you used a wedge style head. you need to use a stock type head because just about all aftermarket heads are based off of the stock design. wedge heads are like big block or ls1 heads (can't remember which) i'm pretty sure it has to do with the valve possitions. either way wedge heads will yield quite a bit more horsies than a regular small block head will.

 

Hey- thanks for the desktop dyno results. I am using 64 cc heads for now with 1.50 exhaust valves and 1.94 intakes. I hope i have better luck with the proform roller tip rockers than you did fast third gen. I would still be looking around 380 Hp with these heads right?

 

Alright, thanks for the Wedge Heads tip! I changed them over to Stock type, though it doesn't seem to have made much difference. When I choose the Stock Smallblock Air Flow profile, it changes the cylinder head type back to Wedge. Go figure. Anyway, voila!

I also upped the compression to 9.5:1 to better reflect the 64 cc combustion chambers. It is about the same as the other chart. Add some nice Vortec heads and you'll be right on to 400 hp

 

And here's the torque and hp tables. This engine should be the equal to an LS1.

 

With those 30cc D-dish KB pistons, 64 cc heads and an undecked block,
your compression ratio is going to be a little low.
You can correct this by "0 decking" the block so the pistons
come right up to the top at TDC. Remove about .025".
and milling the heads to get 60cc's. about .030 to .040"
The top of the block and head intake flanges will need to be
milled to correct alignment then. A qualified automotive machinist can help you with this.

this will raise your compression ratio from 8.65:1 to
9.38:1. Should be just about right for 92 octane gas.

The 18cc or 22 cc KB pistons would have been a better choice.
You'll have to "mock up" the assembly to check for rod clearance
anyways so you can measure and correct your deck height
then.
With a nice home port job on your heads and correcting the cr.
you should get 400+ hp and 450+ ft/lbs torque.

 

Thanks for all the specs guys, I am kicking myself in the *** now for getting those 30 cc dish pistons My dad convienced me to buy them so i could run pump gas, wish i would of got the 18 cc ones now. Guess ill have to see how it works out, might be pulling the motor back out this winter. I really dont want to get into doing all that decking you were talking about, maybe just get some good heads and a little bit of porting.

 

Well, the loss of hp from compression is not huge, maybe 10 or 15 hp or thereabouts.

F-Bird'88 is one of THE smartest guys on the whole board, though, so anything he advises is well worth considering

Especially the head port/polish work

I hope you have subframe connectors.

 

To back up what Fast3rdGen said, I had the Chrome Moly Roller Tipped Rockers for a very short time, right up to when 4 broke, and took out 4 push rods.

 

You guys are scaring me with these proform roller tip rocker stories here. Were you cranking some high rpms when they broke?? My camshaft is a little bit smaller than yours, maybe your high lift cause them to break??? I hope mine will hold up for me.

 

I run those same Roller tip Ball and stud stamped steel rockers
(mine are Crane). I've had no problems with them.
I think the others are refering to the Proform
aluminum body roller rockers (blue straight body). I've heard
a few horror stories about them myself. Proform has a new
contoured body (also blue) alumium roller rocker that is advertized as being a lot more durable. No personal experience myself. The rockers you have will be fine.
One benefit that those "low tech" stamped steel rockers have over a full roller rocker is that by their very nature any wear
can be adjusted out. (Any wear will take a very long time).
Where as a roller rocker becomes sloppy when it wears.
This slop cannot be adjusted out.

 

glad to hear that f bird 88 i was starting to wonder about those rocker arms. Now back to what you said on your last post about "decking my block" what does this consist of? and how much would i be looking to spend on the total job of trying to raise my compression like you stated?

 

You'd have to measure your current deck height.
You'll need the block piston, rod, crank and bearings to mock it up
for measurement. I like to measure the deck height of the old pistons before teardown then measure that old piston's compression height and compare the compression height of the new pistons. Then have the block machined (decked) to
the spec I want.
Minor decking needs no further work but beyond a certain
amount and the top of the block has to be milled to correct
intake manifold alignment. Also when you mill the heads to reduce chamber size, the manifold matting face needs to be milled
by and certain factor to correct manifold alignment or the ports
and bolt holes won't align. The factor is either 75% or 125%.
I forget which. The amount you'll have to mill off your heads to remove 4cc's is only an estimate.
Usually you can flat mill a chevy head up to .060" safely.
Machine shops usually charge so much for the setup and first cut and then so much for each additional cut nessessary.
Usually 1 cut is .015". I would estimate the whole job at
$250 to $300 (can) Like I said before you'd want to enlist the help of a competant machinist and get an estimate from him.
I based my compression ratio calculations with
these specs

stock block 9.025" decks
KB pistons would be .025" in the hole
felpro .042" gasket
64cc head
30cc piston dish 8.65:1
-------------------------------------------------------------------
corrected to
decked block 9.00" deck height
same KB pistons
same felpro gasket
60cc heads 9.38:1

You can download a good compression ratio demo
from Performance Trends on the internet or
go to the KeithBlack site and use their online calculator....

Keep in mind that when you deck and mill for compression
you move the valves closer to the pistons @TDC,, but with your
cam choice this shouldn't be a problem.
You could always keep the low compression and bolt on a blower.
Hope this helps.

 

i was running a .450/.460 lift cam at the time with some stock springs and the motor was turning 3000rpm when it broke.

 

Thanks for all the info F bird 88, i think im just going to put the motor together how it is and see what it has.. if its not good enough ill save up and slap on a holley procharger. Im not really too worried about the rocker arms, i plan to put on some decent aluminum heads after this winter so i will put in all new stuff. Thanks for your thoughts though guys, ill let you know how much HP i came up with, hopefully that desktop dyno is right, 380-400 HP would be fun.

 

I agree about the Proform Roller rockers...I had a set on my 406 and one of them after about 5000 miles. Broke in half where the stud passes thru it, the aluminum just cracked and the large roller bearing fell out. The rocker body was just bouncing around. I will never use them again, IM using a set of comp cam steel rockers with no problems so far.

 

You guys are talking about the aluminum full roller rockers i think.... i have a set of steel roller tip rocker arms.

 

Desktop Dyno 2000 is usually within 5% of actual power. You are right in the ballpark with your estimate. Vortec heads will really put you as close to 400 hp as possible, with civil street manners, too

It is that nice fat, flat torque curve that you are going to like the most :hail: :hail: :hail:

 

Thanks for doing that desktop dyno for me sitting bull i appreciate it and i will let you know how much HP i really came out wtih once i get it all done.

 

I may have missed it but did you say you were running a Performer? I would for sure get a performer RPM instead, it has been tested on big inch engines (383,400, etc.) and there is a TORQUE GAIN, and a HUGE horsepower advantage to the RPM...
totally opposite of what everyone thinks! Think it is the extra inch / air flow that makes it so it does not suffer from a low end loss... ANYWAY..

I run it (perfomer RPM) on my vortec 388, with the same cam XE268, with 1.52 comp roller rockers, and it idles at 800 rpm, and trust me it is NOT soggy on the bottom end!

 

Hey bumpad82- Yes it is a performer RPM however it has a egr spot on it that will be blocked off, it is one that my dad had laying around im going to use for now, im running low on cash these freakin motor parts are too expensive!!! I plan on getting either the performer eps or the rpm air gap. How does that cam sound in your car? give it a nice rumble or is it pretty smooth?

 

The only problem with Performer RPM intakes is that they often won't fit under the hood. Some guys are lucky but most aren't

 

i was using proform roller tip stamped rockers as well. if ya want i can mail you the ones i got left to replace the broken ones you will have shortly after you get your motor running lmao. j/k

i hope the rocker arm gods are better to you than they were to me. i guess that night on the way to jegs they looked at me and said "bad you've been.....die you must!!!!" *BLAM RATATATATATATATATATATATATATAT!!!!!*

 

comp promags for about 240 on ebay.

 

LOL no thanks i wont be needing any extra rocker arms.... im not too worried about breaking them.. Ill let you know if they hold up for me, i dont see why they wont.

 

FYI, For anyone who says that a stock t-5 wont hold up to a 400+ CID small block. It will. I have an 84 T-5 that, knock on wood, is just fine. I am running a 10.5 to 1 409 with 220cc ported airflow research heads, and big 305H .525 lift cam, and 1.6 roller rockers. I haven't dynoed yet, but I am sure that it is at least 450 hp and 400+ ft.lbs. The best part is that I am running a 3.08 rear end. Talk about strain on the tranny. The key is to not put too big of tires on the back and start straining things. No dropping the clutch at 4000 rpms. Trust me, with a 400, you don't need to drop the clutch, just get the car rolling and drop the hammer, you will have white smoke and and counter steer everywhere. Just my $0.02. :lala:

 

FWIW - We stopped selling the Proform and "house brand" roller tipped rockers - these are the stamped steel rockers that look like a stock rocker with the roller tip. Too many were coming back broken. Later on we received a warning from our distributor in a special mailing not to exceed .450 lift or exceed 320# open pressure,, which would only allow you to run with stock, or mild upgrade 1.25" hydraulic springs (depending on how close you were to that .450 lift limit). We continued to sell the Crane stamped roller tip and had no problems with them - they looked of better quality and were heavier in comparison.

 

the 406 is in my new 86 camaro z28 finally

 

good job dude

fuel injections ownz j00 :lala:

 

I had a set of comp cams stamped steel roller tip rockers and broke two resulting in 2 little round holes in my valve cover. comp cams told me i had too much spring. I was turning 7500 when it happened.

 

I have had a T5 transmission in my car since i built it and i powershift all the time. I race on weekends with slicks. everyone told me it was going to blow so i got a spare sitting here but never had to use it. When i put the 355 in, the transmission had 127k on it with a 2.8.

 

Bull s h i t !! There's still at least 2-3 inches left even with a holley carb.

 

i have a 350 with a wieand Xcelerator intake, i have the edelbrock proflow air cleaner, it dont fit and thats one of the thinnest filters, i have a edelbrock carb too
so my filter is kind smashed between my carb and hood lol

 

Ahhh! The voice of eloquence has spoken ...

Funny how almost everyone else finds they can't get the lid down--except for you.

The folks who can get the hood down are doing so with extreme drop base air cleaners--such that they have no more than 1/2 to 3/4" of space between the top of the base and the bottom of the lid. Hardly seems like an aircleaner worthy of the name.

But Odyssey knows all ...

 

Yes I do Know why ? Because I used to have an edelbrock RPM intake, a holley and a drop base aircleaner on my Z28. And still had plenty of room between the top of the cleaner and the hood.

 

my bird has a performer, a holley, and edelbrocks, drop base air cleaner, with a 3 inch filter it just touches the sound deadening mat under the hood, so i hunted around and found one that is 2 3/4in tall, cuz a 2 1/2in interfeared with the choke horn.....

what a headache, i wanted to go with the rpm too, but i couldn't for fear of not fitting, i'm glad i didn't try it

 

but... are not designed to. Thats what ebrock makes the performer for.

 

400's SUCK!!!!! *** damn if i only would of known all the trouble this motor was going to give me!! Here is a list of all the headaches i have had to deal with so far:

Rods hit camshaft
Installed cylinder head only to later find out there is an
oil plug half way under the head next to the oil pressure
outlet.
Installed motor with t5 tranny stil in car, fought for about an hour
to line up the splines on the tranny with the clutch
Had to have 350 flywheel balanced for the 400, because
a 400 flywheel will not fit into the stock bellhousing
My latest problem i found tonight after getting everything ready to fire except for the exhaust and starter... im thinking hell yes im going to get to hear this baby tonight, so i get under the car with my nice new GM mini starter and go to put it up there only to find out that the 400 block has a stagered starter patern and i got a standard starter!!!!! so now my dad is going to drill and tap the block for me, (he says he has done it before and it has worked) so we will see what happens. Someday this car will see the road i promise!!! The car sits nearly completed for now, half the exhaust and starter is all that is left!!! (And ball joints...)


Oh yeah and for you guys fighting about the air cleaner fitting under the hood with the edelbrock carb, there is no way that mine is going to fit.... def need a low profile air cleaner

 

you would have found out about some of these problems and been able to plan for them if you had looked around on here a bit. I am building a 406 with 5.7 rods and plan to modify to clear the cam. not a problem if you know to plan ahead. same with the flywheel and the starter.

it sounds like you have a sweet ride in the works. I will be around 400hp/450tq. I am going for the performer rpm and worked vortecs with 1.6 RRs. I plan on buying a different hood anyway and I will deal with clearance issues that way. I am still looking for the right combo for pistons. I was thinking .015 deck job, 18-22cc dish, and a .030 gasket. That gives me around 9.6-10.0 CR and .039 quench. Oh yeah, I will be using the T-5 until I can afford the T56 also.

 

yeah.... i knew about some of the problems i was going to have but damn this car is really starting to **** me off i want to drive it so bad!!! Grinding the rods was no big deal just very time consuming, double checking all the clearances to be sure they were allright. Sounds like you are going to have a pretty nice motor going for your car..

 

I have a Performer RPM, Holley 750, and a regular base Edelbrock 14" cleaner. I hade to cut about 1/4" off 2 studs sticking through for the hood buldges. Other than that, all is well. And on the Proform issue, they swapped my broke set for a set of the curved aluminum ones. No problems since then.

 

The car is on the road finally after many headaches and busted knuckles.... running pretty strong cant wait til i can actualy get on it... only problem is my clutch isnt going to be enough for me anyone have suggestions on a clutch setup that will work with the stock slave cylinder? Other problem is im loosing a little bit of oil and smoking a bit but i dont think my rings are seated yet so im hoping that will all go away eventually.