Mikey65

What are going to be my major limitations to making a 450hp look stock? I thought of the intake, but figured even a performer RPM can be made to look somewhat stock.. or am I dreaming? There is room for an oil tuber isn't there?

What about exhaust? Seems like throwing manifolds on a 450hp capable motor is a waste, but headers are a dead giveaway. What about the 2.5" manifolds that are out there? They are $275 each but do they at least increase flow substantially?

And lastly if I go with a roller can and roller tip rockers do I need tall valve covers? If so I assume the stock 300hp covers won't work.. and if not what will?

427Hotrod

Do a search on 632C2 and study his red '67 convertible. He's done all the homework for you..chassis dyno'd it and took it to the track. Let's see...iron heads, manifolds, full pipes out the back, pump gas, hyd roller cam, looks just like a 327/350...makes over 400 RWHP and runs low, low 12's in street trim!!


JIM

mikem350

Funny, that's what I'm doing with my 454 BB! All I need is an original 425/450 alum intake, carb, and headers to get my goal of 450 HP

Start with the biggest motor you can (383/400 cube).

How about a "stealth" nitrous system? Go vist the street racers sometime...

Mikey65

I know I can find a motor to make that.. most likely a 383 as I loved the last 383 I had. But it's a matter of what I ( meaning wife) wants to spend and things that will be dead giveaways.. like tall vavle covers.

I tried searching 632C2 and all I find are posts about some 900hp monster..

panchop

performer RPM manifold, 11/1 TRW pistons, Lunati solid lifter cam, 1.6 shaft rockers, 2.5 inch ramshorns hoged out to meet ported 292 heads, into allens 2.5 inch sidepipes. i kept it a 327. sounds bitchin but i haven't sorted all the bugs yet.

Mikey65

I can't see your image on photobucket =( Gov computer..

KyleDallas

Here's a thread on oil tube modification for aftermarket manifolds

http://forums.corvetteforum.com/show....php?t=1626548

The cheap and easy way to 450hp on a small block
1. Dart Platinum Iron 200cc Heads- Platinum IE's.. not the regular IE's
2. Stoker Crank 3.625-3.875

The rest is tuning with cam, carb, mani, exhaust..
you could wring 500hp out of that combo.. but you'd
need to run headers..

It's very, very difficult to get 450hp out of stock, unported
Double Hump heads...AaronZ28 is the man if you want to use
stock components..
I feel that Double Humps are a bad choice if you're wanting that
much power..
You're going to have to run big compression
with stock components to get it there.... I prefer good heads
in the equation so I don't have to max compression, cam, or
rpm...

Dart Platinum 200cc Flow Data
lift.....cfm In/ex
.300....194/158
.400.....242/198
.500.... 274/208
.600......283/214

Competition Products has the Dart Platinum 200cc/64 for $670/pair
bare... that's a decent price on Platinums.. you might find better..

You could also make a 450hp combo using the Bowtie Vortec Heads
from GM.... they also flow very well

Mikey65

I was actually planning some type of aluminum head and hrd roller cam. I don't want to use stock components, just have it look stock. Nothing on the motor will actually be stock aside from valve covers, ignition shiielding, etc.

Right now planning on a 383, but still clueless as to how I want to do it. As far as I see, to do it right it's going to cost $ no matter which way I slice it. So I am shooting for October this year to start throwing it in, which may end up being the same time I take the body off.. and if I do that might was well install the tko600 .

Anyways.. I contacted 632C2 about his motor he did, and seems like he has a stout setup running almost 11s. Things I wonder about are machining the intake for the oil fill, grinding edelbrock logos off the intake, porting the exhaust manifolds, and any other nitpicking things I am not thinking of.

Jack60

This isn't stock????

Mikey65

Can't see your pic =(

Mikey65

Here is a PM I sent 632C2 who asked for me to post here for all to benefit:

I pretty much want to do what you did. That looks fantastic! I was planning on making a sleeper 327/300, but it seems like a 327/350 is more realistic.

It's encouraging to see the power you got out of 2.5" manifolds as I thought that was going to be the weak link. How much did you port the manifolds and did you do the work yourself? I have no access to a machine shop..

I was also planning on a RPM manifold, but I thought that if I try grinding off the Edelbrock logos, I would be left with an area that definately looked like it was ground down. And what about the oil tube?

I saw you also used a 825 MD for the carb. I know that BG likes to powdercoat their carbs for show.. did you just go along with this or try to hide it's appearance? Does it stick out?

And why did you decide to use iron heads in place of something like AFR or similar?

What were some other major obstacles that you encounted to making a 11 second car that looks stock? I am trying to think of enerything from a stock looking pan with windage tray, stock looking fuel pump and filter, fuel lines...to.. well everything.

632C2

I get a couple of inquiries per week pertaining to my red '67 convertible with the 383 and am more than happy to respond to them.

I do all of my own work with the exception of specialized engine machine shop operations and exterior bodywork/paint.

My goal for this motor was to make it look like a 1970 LT-1 motor and NOT a 327/350 motor. I have always liked LT-1's but have never been too enamored with 327's. My favorite appearing small blocks of all time are the LT-1's. Also, I knew a couple of guys back in the 70's and 80's that put LT-1's in their mid-years and it was cool! I am a Big Block guy by nature and I like cubic inches. That is why I decided on a 383 for this car. I started off with a ZZ383 shortblock due to time constraints - have you ever tried to get machine shop work done in a hurry - and because I wanted a motor that didn't leak. With a 1 piece rear main seal, 1 piece oil pan gasket, and updated oil pan you reduce the risk of leaks dramatically.

I ported the exhaust manifolds as much as I could without compromising sealing. Although I have done more than my share of head and intake porting over the years, I am not a professional head porter by any means. However, I try to be as meticulous as possible about removing obstructions, smoothing, and blending. The only real way to port anything is with a flow bench and I don't have one.

Now the intake is another matter. I spent 4 days welding and grinding on the Edelbrock RPM to try to closely match the LT-1 manifold. I set the LT-1 manifold next to the Edelbrock RPM and went to town. People with a keen eye will be able to tell that the manifold on my car is not an LT-1 but by the same token those same people cannot recognize what kind of manifold it is. Because I was trying to make this look like an LT-1, I did not use the oil tube.

The carburetor was a different can of worms. I ultimately ended up with the Demon for a number of complicated reasons but mainly because if offers better air vent clearance than a Holley and I really have to have a carburetor I can tune properly. This means replaceable air bleeds all the way around and replaceable IFR's in the metering blocks. The Demon I have is not powdercoated - in fact, I was not even aware they did that. With the air cleaner on the motor, you can't see the carburetor anyway.

I went with iron heads for two reasons. 1) I had spent a lot of time getting the car to sit just like I wanted it to and going with aluminum heads would have required that I start all over again. 2) The Dart Iron Eagle Platinum heads I selected had excellent dry flow numbers and were developed on a wet flow bench - besides I am a Dart fan.

As far as trying to make it look factory showroom stock, I gave up on that real quick. I got the high-performance factory fuel pump and was shocked to see the fuel pressure drop to 3 psi on the dyno with the factory fuel lines. It went up to 4 psi with fabricated -6 fuel lines but that still wasn't good enough. Remember, the car is sitting still on the dyno with no G-forces to overcome. I spent money on a couple more factory fuel pumps before throwing in the towel and getting a Holley. Problem solved.

Stock is cool but not when it compromises performance. The major obstacle I had to overcome with my car was wheel-hop. It was horrendous. I fabricated a traction bar and the problem went away.

I will be taking the car out to the track in a couple of weeks to try to get into the 11's. Once I get there my goals will be met and I will be able to turn my focus to one of my other cars.

I have included a DynoJet graph of the before and after. I made a total of 93 dyno runs to get from 351 rwhp to 416 rwhp. The first runs were made Jan.1, 2006 and the final runs were made Sept.20, 2006.



I hope this helps.

Steve

Mikey65

It does help..I also want a 1 piece rear, 1 piece oil pan, and a 5 qt updated pan.

I never really thought about that with different heads. My car rakes a little forward and I would like to get rid of that. Maybe the alum heads would fit that? I used DART Pro1 on my last 383 and loved them.. People rave about AFR but I have never used them and seem expensive. Are you using the 200cc heads?

The fuel is another issue like I said. There are "performance" fuel pumps, but most have the standard edelbrock finish. I have found a few with the cast finish but no idea how they flow. And I assume the entire fuel line from tank to carb would have to be changed anyways with a motor like this? As for the carb, demon seems like the way to go in order to fit this under a sb hood. Seems people have problems fitting holleys but BG fits ok. Do they not make fuel lines for 450hp motors??

Ignotion is not a big problem I don't think, and I was thinking of running a 6AL box assuming I can hide all the wiring under the ignition shielding, and mount the box behind the verticle column in the interior.

What about valve covers? I thought tall valve covers were in order if you use rockers over 1.5 or something along those lines?

And where exactly did you get your ZZ383 shortblock? I have found the HT383 short but no ZZ383.

Thanks..

632C2

As far as the rake, it really depends on your springs as to how far the front end would raise back up. I have the 200cc heads.

I am using a factory replacement stainless steel 3/8" OD fuel line from the tank to the pump. I replaced it when I did the body off restoration. I fabricated new lines from the pump to the carb because I wanted the best flowing system I could find and also to be able to incorporate a large replaceable fuel filter. I couldn't find any factory type fuel lines that would fit the bill.

My car had the factory transistor ignition when I first got started. I replaced it with a Crane HI-6 unit because I had one sitting around and I wanted the rev-limiter. There was ZERO power gain from the Crane.

As you can see with my deal, tall valve covers are not needed with roller rocker arms. I have the Crower stainless steel that are kind of bulky and they fit with just a little massaging of the oil baffle.

The ZZ383 shortblock is a factory Chevrolet item. I got the best price from Sallee Chevrolet. Sallee has since been bought out by Gilbert Chevrolet and I don't know about their pricing. The part number on the short block is 12499106. My son bought one last summer for his 1969 Corvette coupe. How's that for a testimonial?

Steve

Mikey65

How much machine work is generally needed on a new GM block if any if I want to assemble my own shortblock?

KyleDallas

Clearancing for the Stroker crank... depends on the internals..
some will drop right in...others need some basic grinding on the side walls to clear the crank and rods... you could acomplish this with
an air grinder.

I do not know if a GM block purchased from GMPP would need
bore work or not... if it came with a 4.00 bore you'd need to go .030
for the 383.. so you are boring anyway if you're going 383... other wise you've got a 377...

The GMPP 383's come with a little different set up than most
converted 350's.... they use a 4.00 bore and a 3.80 inch stoke...
vs. a 4.030 inch bore and a 3.75 inch stroke of most 383's...
GM wants too much for their 3.80 crank.. otherwise I'd suggest it..
I was quoted $1000...you can get an aftermarket forged for $450 to
$650 in the 3.75 in stroke... you just need the 4.030 bore to go with it.

I would encourage you talk with local machine shops... alot of times
you can pick up a block for strictly the cost of the machine work
if someone has left their block at the shop.... it happens alot...
Or check in the C4 section here...I like getting cores from the local
pick a part... I get all the brackets, oil pan.. I can sell the heads,
throttle body, etc. and often have basically Zero in my block cost.

The ZZ4 uses a standard 350 production roller cam block... all you'd
need would be a 1987 up 350 block.... this would also allow you to
run Factory GM roller lifters which are cheaper than the aftermarket
drop ins.

Ironcross

If you want to hide HP, paint everything orange. [chevy] no matter what it is, water outlet, waterpump, valve covers, heads, and no matter what alloy they are. No shiny bright stuff, and leave the hood closed most of the time. Interior, no hot rod guages PERIOD. Exhaust, quiet Walker Dynomax mufflers. They are the best flowing mufflers anyway,

60vett

Does this mean you are viewing at work?

Mikey65

Means I am deployed overseas, on alert for 5 days with nothing to do. So yes I am at work.

Mikey65

I wanted to make it look like a 327/300, but I think a 327/350 is more realistic. The valve covers on the 300hp are "caved" in the center which I think will cause a problem. The RPM intake is also going to be a dead giveaway even if I powdercoat it orange, so I will leave it cast most likely. Same with the air cleaner.. dual snorkel on a 450hp motor is just sad.

Everything that should be will be powdercoated chevy orange. I want to get this right down to the GM radiator hoses and steel fuel line. I even want to modify the stock fuel filter if I can and make that work.