Hi,

I am still trying to figure out what to do with the engine of my '67.

I have to build a new engine because the stock 305ci is kinda slow. I thought of building a 383 twin turbo (never enough of hp/tq). If I don't exceed the 3000-3500 rpm I'll just drive a 383, and when I need it, I have the extra power. Point is that turbos are very easy to find here in Europe, but roots and superchargers are almost impossible to find. Shipping one in from USA will cost me double the price of the part(s), so shipping is not an option.

As I start building the engine from scratch, I can save money and buy a better part (suitable for 750+hp) then a part suitable for 500hp. I don't think the price will be a very big difference between them (correct me if I'm wrong).

The headers I will make myself, so that won't be a problem. I know that e.g. Holley makes carbs for blow-through applications, so that won't be a problem also.

I was planning to build the 383 engine with everything forged and suitable for many horses (800-900?) BUT I will build it without turbos so the engine then has a CR of approx 8.0:1
I guess that the 383 then will have something like 300(350?)hp without the turbos and so my th350 and 10bolt will survive. When I finally saved all the money I need, I can upgrade the tranny and rearaxle.

Here's my problem: Which mods do I need to do besides better brakes (I got the 4 piston discs in front), better cooling, subframe conn.?
I would set the turbo on low boost (solenoid for setting the wastegate inside the car...variable boost), so that I'll drive with not that much hp (500), and it would be still streetable.
Do I need to do heavy mods on the car to make it stiffer, and if so, what do I need to do?

Thanks

Definately going to need some subframe connectors. Also, go with solid body bushings if you don't have them. Also, what kind of rear springs or traction devices you running? The torque of the 383 will put them to a bigger test than before as far as wheel hop goes.

John,

All the rubber for suspension etc. are now PU, so I guess this is right.
At this moment I have the stock monoleafs, but in the near future I want to upgrade to fiberglass ones, or multi from Hotchkis. I also have a front 1" swaybar and a rear swaybar, and lowered the car about 2". But what do you mean by traction device graemlins/clonk.gif sorry, but I'm Dutch :D

Thanks

DL,

Is it possible to turn a set of stock, log exhaust manifolds up-side-down on your car and then use the exhaust pipe flange as a mount for each turbo???

And maybe side to side??? I have wondered this for a while but since I can't afford to play with TT's, I have NEVER bothered to check my '67 out close enough to see if it is indeed possible to do this...

If possible it may save you a real hassle making up-side-down headers if you want to mount the TT's up top instead of down along the sides of your block...pdq67

No problem David, graemlins/thumbsup.gif

By traction devices I meant some traction bars or something like that. Your stock monoleafs will end up twisting up a bit with the kind of torque you're talking about. If you're pushing very high horsepower in the future too, you might end up breaking the composite/fiberglass springs if you decide to go that route. If you end up with the kind of horses you're talking about I would put in a roll cage as well to add some frame stiffness.

Good luck with it. Sounds like a really neat project!

pdq67, I was thinking of making the following headers

http://www.grapeaperacing.com/GrapeApeRacing/camaro/pics/header1.jpg

I thought the owner of this car also visits this site....but I'm not sure.

It seems to be a simple header, and on pro-touring.com I also saw a their headers... I can weld etc. so no problem here.
The only problem I have is to know which mods I need to do to the car.
Subframe connectors, traction bars etc. can and will be done, but I'm not sure if I want to have a rollcage in my car....I don't want it to be a race-car, I want it to be a 'nice lowered 67 with original interior and a non-original drivetrain and a souped-up engine'. And I also must know where to weld stiffness in the car.

Any advice on the max tq and hp I can go WITHOUT using a cage?

Thanks again!

Max HP and TQ without a cage is basically where I am at with my naturaly inspired 383 ;) sorry couldn't resist. That is roughly 450-500 HP, more than that and the race tracks require a cage because your 1/4 mile ET's start getting into the high 11's.

You could put about anything you want to in a street car that will never see the track, but I think NHRA and IHRA know what they are talking about when it comes to safety. So IMO a cage is a good idea at about the 500 HP mark whether you race it at the track or not.

That is below the belt Eric :D ;)

I think you're right on this, if the IHRA and NHRA requires a cage if you get below the 12's it should be best....

But the thing is I don't want to cut the car to get the cage in.... I would only do this for my safety, otherwise I would weld everything in it. I also want it to be reversable, so that I can get the cage out, when the engine has to go for one reason or another...

Do any 'bolt-in' cages exist which allows you to keep everything original, also the back-seats etc.? (The cage may go through the (D*mn, I forgot the English name for it?!) anyway, the thing where the speakers can be underneath the back-window, because it can be replaced later..)

The package tray. graemlins/thumbsup.gif

DL,

A set of 2.5" rams-horn cast-iron stock manifolds turned up-side-down with a small spacer and a Turbo flange and wastegate pipe may save you a bunch of fabricating!!

But I sure do like thre looks of the headers you showed... pdq67

Thanks protouring :D

pdq67, do you also have a guess on which cars I can find these 2.5" rams-horn cast-iron stock manifolds? I don't want to sound too lazy, but we don't have that much old US cars running around here..... I think I know the looks of the manifolds you mean, but I don't have a clue which cars have them. (most US cars here are V6)

And another thing is the wastegatepipe..... I also saw this on all V8 turbo engines, but why... The cars I had with a turbo, the wastegate was attached to the turbo itself, (not an internal wastegate!) but on the outside like on this pic
http://www.marktplaats.nl/fotos/autodiversen/ondbmw/15275.jpg
Is this a difference?

I'm sorry, but the big 2.5" rams-horn manifolds came on the '64 and later hi-po carb. and fuelie Vettes!
I don't think they came on any other cars but may be wrong. The thing with the A, F and X cars is that the center dump tended to hit/dump right at the frames and subframes center crossmember. Therefore, the exhaust pipes couldn't be installed..

Some of the smaller 2.0" and maybe 2.25" rams-horns did point to the rear instead of straight down like the Vettes, but I can't tell you what cars they even came on... I suspect Big cars and pre-'66 Chevy II's???

GM has licensed the 2.5" ones to be repopped by Original Parts Group, (I think), but they are pricey to say the least...

I have seen them at the car shows and I always wanted a set but since I can't install them on my '67 Camaro, I just couldn't justify buying them to look at!!! pdq67

Let me tell you. At the drag strip the anouncer said the dragster in the tower lane is running twin volkwagen engines wiiitttthhh turboooo'sss. I thought yah he'll need turbo's to at least try to keep up with the other guys. The rail sounded like a whistling rocket going by and runs 8's or lower. Unreal when power to weight ratios are involved. Anyway going turbo having the revs up at launch might add a few or more seconds to your time smoking tires and all. Have fun finding the right rpm and set-up.

Snatchin, I would almost say: Don't underestimate the power of turbos! My intention is not to get into the 10's with the turbo setup, but if I could dip into the 11's that would be great....

Probably I could do the same with a (here it goes again!) naturaly inspired 383 :D ;) like Eric has. But my point is that I will never use slicks to drive (it will nevere srr the strip!) so these numbers will be a bit higher on normal street tires.....
I'm thinking of running a low CR and a low boost to get 450hp. If the time is right (upgraded tranny and rearaxle etc.) I can run more boost and go to 650 hp or more. I just want to build only 1 engine, and in just 5 minutes working on the car gain 200 hp or more.....