Don Terrill’s Speed-Talk

Ok, I want to get some opinions on this and how, or if it's possible.

What I have SBC 350, 062 Vortec heads 2.02 valve (ported with correct cross section should end up about 190cc intake runner), RPM intake with the porting needed to work with heads (as much as possible). Compression in the 10.0 - 10.4 range (I can play around to get final compresion) typical headers, holley, correct timing curves, ect.
This will all go into a 3400lb car with 3.08 gear and muncie with the 2.52 first gear. Gear is based on street cruising, I am not opposed to change out to a 3.73-4.10 for fun runs at the track. Would like to go mid 11's with drag radials in 1500' DA, and around 18-20mpg street mileage with the 3.08 gears.

My goals are to build as much power as possible 450-475hp with simular torque numbers with a good flat curve yet still work to get the best mileage and drivability possible, the car will be full street with many fun track runs and some limited bracket racing. I would like to be able to have a power range as wide as possible with shift points at the 6300-6500 range. Would like to get as much idle vacuum possible. (12-14" at 900rpm)

I have been looking at solid lobes as I do not want to have to worry about the hydraulic roller lifter collapse at high rpm and I don't mind keeping track of the lash.

Would the smaller 230@.050 intake and 236@.050 exhaust type lobes in a solid roller work in this application and do what I am looking for? I have never played with anything to make strong power and still keeping full street manners in full focus. I know I cam make 500 plus hp with more cam, but my challange is good power plus efficient design.

Anyone with real world combinations or lobe advice?

I know this all sounds like dreams, but if you don't try to push the combo you just as well give up.

-Bobby-

i was reading about a modern version of an old vette cam, the original solid cam had long ramps and lousy idle vacuum, but had a power band of 1800 to 6800+.
So with the fast modern ramps, that should do the trick.
I'm sure u will get lots of other good ideas, too.
The good mpg is easy once u know how. see my site.

if u go to corvetteforum c1 section, look for
topic; 30-30 camshaft dyno results
date; 11-15-2010
it is a test of the Predator 30-30 on a 114 LSA
in a 69 302 Z28 STOCK UNPORTED heads, 11:1 stock
it was still making excellent power at 7400
peak around 6800 294 rwhp on a Dynojet chassis dyno.
i'd expect to move the rpm band down ~300-500 rpm in a 350.

arron tried a bunch of cams and likes this one best, and says he put one in his 64 c2 too! a year earlier he tried the 1970 LT-1 cam in the 64 and it made only 190 rwhp!

With a solid roller, you should be able to get the power you're looking for, in the RPM range you want, but it will depend on the port job.

Using the flow data on the AFR 190 vortec, I'd recommend this cam.
Part# R71390-72395-110
236/240@.050"
.390"/.395" Lobe Lift
110 LSA

You should think about a 5 speed transmission to get all of what you want.

Matt,
Good information on the mileage, the car will get 19mpg now with the currect 327 in a variation close to L79 power numbers.
The 30-30 based cams are going to be way overboard for this thing as I plan to make many road trips with 3.08 gear, and that puts the cruise range in the 2200-2600 range. Also I want to go roller for the added area and lift as the heads will be good to the .600 lift mark plus a good bit more without backing up.

Mike,
That is close to the cam numbers I have been looking at, but I wasn't sure I was going to get the idle vacuum and low end I want to try to keep. That is why I was looking at the smaller lobes and hope that they would hang on to get the top end I was looking for.
The heads will have numbers that or better than the AFR 190 Vortec head, but I am also going to focus on porting the manifold to "try" to keep up with the head flow.

One of my biggest areas of concern is at what point to advance cam timing to get low end or just use a smaller lobe that will carry into the higher RPM range I am looking for?

F'Bird,
The 5 speed will come in time, just like the history of still using the Muncie, but better performance and strength will wear out that novelty

I had 3500lbs 69 chevelle with a budget "throw-down" 350.
I wanted to run around 12.0s and be a mellow cruiser, with decent idle and mileage.
Threw a cheap (speedpro) shortblock together (10:1) with a Bullit girly roller 232/238 on a 112lsa.
Old TFS twisted wedge G1s (homeported) and RPM and 750DP.
I think it had around 10-12 of vac, nice musclecar sound, idled with AC on.
Car had a 200-4R (2200 stall) and 411s. 1 3/4" hookers SC and 3" exhaust.
One track outing it ran 12.31 @ 110.6 with no tuning.
With 1 5/8" headers, more stall and some tuning it would have gone deep in the 11s I'm sure.
Building the shortblock with some better parts, more comp. would have been worth some power too.
I shifted it at 6500, but it kept on pulling, just afraid of the rods letting go, would have gone
faster shifting at 7000 I believe. It 4500-7000!
Got over 20 on the freeway, but I really dont pay att. to that stuff.

LilRacr wrote:Mike,
That is close to the cam numbers I have been looking at, but I wasn't sure I was going to get the idle vacuum and low end I want to try to keep. That is why I was looking at the smaller lobes and hope that they would hang on to get the top end I was looking for.
The heads will have numbers that or better than the AFR 190 Vortec head, but I am also going to focus on porting the manifold to "try" to keep up with the head flow.

One of my biggest areas of concern is at what point to advance cam timing to get low end or just use a smaller lobe that will carry into the higher RPM range I am looking for?

Remember, you can't really compare .050" duration of solid rollers, with Flat tappet cams.
The seat duration on the 236/240 roller I suggested is equal to a
230/234 in a solid flat tappet, or
228/232 in a hydraulic flat tappet, or
230/234 in a hydraulic roller.

Remember, you can't really compare .050" duration of solid rollers, with Flat tappet cams.
The seat duration on the 236/240 roller I suggested is equal to a
230/234 in a solid flat tappet, or
228/232 in a hydraulic flat tappet, or
230/234 in a hydraulic roller.

Yes, I know about the lobe variations with the solid rollers stuff.

How is the vaccum and street manners pulling at 2k rpm?

Am I on the correct thinking that if I need to advance the CL of the cam I need to go smaller on the seat and .050 duration?

What is the seat duration of this cam, do you include lash in that number, I do need to keep it on 93 and if the worlds align and I hit the combustion combination I want possibly 87 octane.

LilRacr wrote:How is the vaccum and street manners pulling at 2k rpm?

You should see about 14" @900rpm
The somewhat short seat duration with the 110 LSA will be fine on the street.

Am I on the correct thinking that if I need to advance the CL of the cam I need to go smaller on the seat and .050 duration?

Not always. Sometimes it just wants one of the opening or closing spots somewhere else.

What is the seat duration of this cam, do you include lash in that number, I do need to keep it on 93 and if the worlds align and I hit the combustion combination I want possibly 87 octane.

The Seat Duration is 284/288@.012", and that is the actual lash point.
We ran a 280/284 solid roller with 9.8:1, and it ran on 87 octane.

So I am not totally off my rocker looking to do a small solid roller and expecting 450+ hp from a capable and matching combination?

Is there anything you see that should be changed to make the whole combination better? Typically I am porting heads and intakes to meet a customers power goal and the cam is picked as I am finishing up my end, I am not good at picking details on cam lobes!

Basically am I leaving anything on the table?

LilRacr wrote:Is there anything you see that should be changed to make the whole combination better? ?

Yea, go to a 3.750" stroke.

it would be real handy to have a timing set with a wide adjustment range

CamKing wrote:Yea, go to a 3.750" stroke.

10-4 I've read that until somewhere around 270ish, there's actually more area under the curve with a flat cam vs a roller. What say you?

Yea, go to a 3.750" stroke.

If I go to a 3.75 stroke it will break the bank on this build, as I am putting focus on the valvetrain rather than the rotating assembly.

The 3.75 stroke will also reduce fuel efficiency, thus the reason for the base 3.48x4" bore design.