CHP 347 or Boosted stock motor?

[Nobody]

Okay it's getting near that time that I need to start thinking about putting a second engine together. I was always considering a 347 Street Fighter but now I am considering a different direction.

For the money of a CHP crate, I could get a rebuilt stock Cobra longblock and put an S-Trim or Kenne Bell on it. I could probably go forged on the bottom end for that money as well.

I think the power level would be about the same between the two setups, no?

 

[BlackVert]

i have a kenne-bell on my daily driver. it is great and i love it, but i have some issues you should at least be aware of while considering going the k/b route:

- it sucks a good bit lot of oil through the pcv. people also say an oil seperator would solve it, but it still robs oil from the back cylinders. moving the pcv to a valve cover is a better solution (imo).

- since the k/bs for our cars don't have an intercooler option, the intake air temps get really high after about 15 minutes of normal driving. that is causing me pinging issues under part throttle. i am going to a water injection solution, but i am not there yet ...

my next combo, if i can afford it, will be a high revving 306 (or 331) with a light rotating assembly and a turbo, and it will have an air to water intercooler.

 

[95snoozer]

I have gone over and over and over this in my head as I fall asleep.

you want power and Most driveability? BLOWER

you will easily outpower the 347 with an s trim

the 347 would need good heads, good compression, good intake, good headers to make good power.

You can bandaid with boost and dont have to have every piece of the puzzle to make power in the beginning.

 

[95strokerPSU]

Sorry to jack the thread, but Snoozer I saw that you used your windshield fluid tank as your radiator overflow tank. Just wondering how that worked out in the long run? Tried sending a PM but you're box is full.

Thanks
Dave

 

[95snoozer]

works great, i will empty my pm box

I now have the 169 dollar summit radiator with it and it is amazing. I dont need a cooling fan unless i am sitting in intown traffic.

it stays at 175 on the highway, and in town with the fan on

Just remove the CCRM and bracket and relocate the CCRM, mine is under the Itake pipe. get some vaccuum line and run it off the radiator to the bottom of the reservoir. I cut out the the latice that is in teh filler neck so i can see in the tank more easily. I had the tank out to hook everything out so you can really see how it works.

 

[Car Nut]

Wouldn't a 347 give you more "streetable" power by giving you more power lower in the RPM band. Blowers are great, but the power doesn't really shine until higher RPMs.

Not sure where you want power, but the more I read on the stroker option the more I like the idea of having good power down low in a simpler N/A 347 setup.

Building a 347? Can't imagine going that route and not adding a good set of heads, intake, and exhaust. I'm sure people have overlooked adding those parts or maybe couldn't afford them up front, but ultimately it must have been the desired goal. For me, a CHP crate motor and a host of other upgrades will meet my needs.

If I'm way off base, please explain and put me on the right track.

 

[SVT3183]

blackvert, i asked you before so i know you're not sure how many #'s of boost you are running but i'm curious what octane gas you use?

 

[BlackVert]

blackvert, i asked you before so i know you're not sure how many #'s of boost you are running but i'm curious what octane gas you use?

sorry, did you say something? i was distracted by something in your sig ...



oh, right ... i am running 93 otcane.

 

[BlackVert]

Wouldn't a 347 give you more "streetable" power by giving you more power lower in the RPM band. Blowers are great, but the power doesn't really shine until higher RPMs.

of course, a twin screw blower is all about low rpm torque ...

 

[95snoozer]

Wouldn't a 347 give you more "streetable" power by giving you more power lower in the RPM band. Blowers are great, but the power doesn't really shine until higher RPMs.

Not sure where you want power, but the more I read on the stroker option the more I like the idea of having good power down low in a simpler N/A 347 setup.

Building a 347? Can't imagine going that route and not adding a good set of heads, intake, and exhaust. I'm sure people have overlooked adding those parts or maybe couldn't afford them up front, but ultimately it must have been the desired goal. For me, a CHP crate motor and a host of other upgrades will meet my needs.

If I'm way off base, please explain and put me on the right track.

i want to trap mid 120s... dont know about you

as long as the car doesnt cause problems to daily it with the way the bottomend power is, Its streetable. To go fast with a 347.....you are going to have a less streetable bottomend.

It depends how fast you want to go, I throw around the s trim versus 347 decision daily. The s trim beats it out on power/ driveability/ exhaust Noiselevel.

my 347 would need 10.5-11:1 with a head that flows closer to 300 cfm than a 185 AFR does, good intake, 1/34 header maybe step to 1 7/8, 28 ounce balancer,

the 347 wins out on weight in my situation by 75 pounds on teh front of the carso it would handle better.... This is one of the only reasons i consider the 347, other than the fact I like being n/a and I can run less injector.

 

[Car Nut]

i want to trap mid 120s... dont know about you

as long as the car doesnt cause problems to daily it with the way the bottomend power is, Its streetable. To go fast with a 347.....you are going to have a less streetable bottomend.

It depends how fast you want to go, I throw around the s trim versus 347 decision daily. The s trim beats it out on power/ driveability/ exhaust Noiselevel.

my 347 would need 10.5-11:1 with a head that flows closer to 300 cfm than a 185 AFR does, good intake, 1/34 header maybe step to 1 7/8, 28 ounce balancer,

the 347 wins out on weight in my situation by 75 pounds on teh front of the carso it would handle better.... This is one of the only reasons i consider the 347, other than the fact I like being n/a and I can run less injector.

Makes sense.

I was taking that approach that a 347 would be simpler and possibly might have fewer headaches than a blower setup. Of course, the right parts have to be put on, but that mostly depends on what the car will be used for. In my case, street duty is primary with only a couple mild/medium road courses each year.

Instead of a 347 with AFR 185s, Edel RPM II, and emissions friendly cam, I've thought about going the route of a 306 and an S trim. Emissions would be a sinch with a 306 and with good h/i and the S Trim, I should have good power, drivability, and durability. Maybe the 306 could be had using my stock block, provided it is in good shape. I use my car on some long trips now and then, so the blower causing too much heat might be a concern.

347 or a blower? Still unsure, but I still lean a little towards the 347 for simplicity.

Nobody didn't say what his goals were exctly, so I guess it depends if he see the track a lot or if a solid powerful daily driver is more important.

 

[Car Nut]

as long as the car doesnt cause problems to daily it with the way the bottomend power is, Its streetable. To go fast with a 347.....you are going to have a less streetable bottomend.

???

What do you mean by a 347 having a "less streetable bottomend?"

Thanks.

 

[95snoozer]

by streetable bottomend, i assume you mean idle- 3k, where you normally drive around town and on the free way. If you drive a 347 that is setup well enough to make comparable power to the blown setup, you will understand what I am talking about.


Do you have an intake and cam? If not, i understand where you are confused.

a blown 94 cobra motor is going to drive like stock until boost comes in, which means great torque off idle and driveability. It would be the idea Daily setup as long as the tune is good. Same with both cases. You dont want to have cold start issues because of a big cam on a 20 degree day and have to sit in your car while the engine warms up. A tune will not always fix this.

 

[Car Nut]

Do you have an intake and cam? If not, i understand where you are confused.

a blown 94 cobra motor is going to drive like stock until boost comes in, which means great torque off idle and driveability. It would be the idea Daily setup as long as the tune is good. Same with both cases. You dont want to have cold start issues because of a big cam on a 20 degree day and have to sit in your car while the engine warms up. A tune will not always fix this.

No intake or cam on the current setup. All stock. With 150K+ on the stock motor, I've started thinking about what the replacement will be. Finishing up the suspension/foundation this year and engine/tranny stuff next year.

The cam in CHP's 347e crate motor is very mild since it passes emissions. Idle would be near stock. As far as heads go, many seem to be happy with the Performer RPM II (which also happens to be emissions friendly). The cam, in my case, would not be agressive at all and that would be fine due to the emissions laws in my area. This or any setup would get tuned.

In the end, I wouldn't be going for maximum power, but more for durability and drivability while hopefully acheiving at least 300rwhp. I figure that a well built 347, even with a mild cam and emissions friendly, could still have the potential of 300 to 320rwhp.

I see your point though about the blower and the lower rpm range advantages. If the stock block could go another 100K miles after cleaning it out and making it a 306, I could definitely see going the blower route along with forged interals to make everything a little stronger. Not sure if that is a stupid idea or a good one?

 

[Black Stampede]

Why not a turbo?

 

[final5-0]

The cam in CHP's 347e crate motor is very mild since it passes emissions. Idle would be near stock. As far as heads go, many seem to be happy with the Performer RPM II (which also happens to be emissions friendly). The cam, in my case, would not be agressive at all and that would be fine due to the emissions laws in my area. This or any setup would get tuned.

In the end, I wouldn't be going for maximum power, but more for durability and drivability while hopefully acheiving at least 300rwhp. I figure that a well built 347, even with a mild cam and emissions friendly, could still have the potential of 300 to 320rwhp.

I may be not seeing things like this and other things you said in above posts from you exact view point

but

It looks like you feel a smaller size motor will be more emissions friendly

Whether it be 300, 350, or 400 cubic inches, I just don't think it matters.

As long as the rings are sealing well and the tune is good ......

Its my opinion you are gonna pass emissions testing.

I discussed this issue at length with Ed Curtis before making my decisions about my combo and he told me you could do way more things with cam specs than the average person would think.

In a nut shell ......

He told me if I could tune it, he could give me a pretty aggressive cam that would produce good power and I would have no problem with emissions.

After I found out what he could do and how much I could accomplish with self tuning ......

Wish I would have asked him to step up the specs a bit

btw ...... I've passed emissions inspections for the past three years and it produces very clean results

Grady

 

[Nobody]

Always put a line item in for tuning. Especially when putting a 347 into a 94-95 car. I talked with CHP on the phone yesterday and I am feeling really good about the 347e. Even with the mild cam in it, it's still going to make more power than my stock motor. I talked to the guy at length about the '95 that they built with the 347e. 5.0 mag did a cover story on the car last year. I have talked with a few owners of 94-95 cars and the shop that did their work and all agree that in order to do it right, you need updatged engine management. The local dyno tuner says that it's possible to do it with a chip. Just about everyone else has gone to a full standalone setup. There are a couple guys who have gone with the PMS but now they are going with an AEM. This known, I would have to factor in another $3k for an AEM and tuning. The guy at CHP said that you can do a lot and still pass emissions if you have cats.

 

[Car Nut]

I may be not seeing things like this and other things you said in above posts from you exact view point

but

It looks like you feel a smaller size motor will be more emissions friendly

Whether it be 300, 350, or 400 cubic inches, I just don't think it matters.

As long as the rings are sealing well and the tune is good ......

Its my opinion you are gonna pass emissions testing.

I discussed this issue at length with Ed Curtis before making my decisions about my combo and he told me you could do way more things with cam specs than the average person would think.

In a nut shell ......

He told me if I could tune it, he could give me a pretty aggressive cam that would produce good power and I would have no problem with emissions.

After I found out what he could do and how much I could accomplish with self tuning ......

Wish I would have asked him to step up the specs a bit

btw ...... I've passed emissions inspections for the past three years and it produces very clean results

Grady

Thanks. I think I read one of your posts a couple days ago or so about a similar topic. How would you rate driveability now compared to stock? Also, what about long Interstate trips? While we are at it, what would you see as being a negative with a 347 for a daily driver?

Thanks again for posting.

 

[final5-0]

First of all ... Great thread and like the Snooze man, I've thought about all this stuff a lot of times

Always put a line item in for tuning. Especially when putting a 347 into a 94-95 car. I talked with CHP on the phone yesterday and I am feeling really good about the 347e. Even with the mild cam in it, it's still going to make more power than my stock motor. I talked to the guy at length about the '95 that they built with the 347e. 5.0 mag did a cover story on the car last year. I have talked with a few owners of 94-95 cars and the shop that did their work and all agree that in order to do it right, you need updatged engine management. The local dyno tuner says that it's possible to do it with a chip.

Agree 100%

Why gather up all that great hardware and not take advantage of all it has to offer with no tune

Just about everyone else has gone to a full standalone setup. There are a couple guys who have gone with the PMS but now they are going with an AEM. This known, I would have to factor in another $3k for an AEM and tuning.

This is my opinion as I have not tried to tune a stroker

but

My thoughts here are based upon what I've seen other self tuners be able to accomplish with their stroker combos

Nothing wrong with the Standalone method

but

I believe I could get a bad boy NA 347 Stroker to idle with a stable lope, make good wot power, and pass Texas annual emissions inspections with my Tweecer

Some who advocate standalone may be motivated by not wanting to get involved as much as they would with PMS, Tweecer, and the like

Standalone can really do some cool things and it goes without saying

and

Its very user friendly from what I've seen others say

however

I just don't buy into the $3 Grand thing to self tune a na stroker combo

I know there are those who have that kind of $$$ to get it done

but

I don't think its a must have kinda thing

The guy at CHP said that you can do a lot and still pass emissions if you have cats.

Not a lot needs to be said here

Grady

 

[95snoozer]

Not attacking, but why build a 347 that makes 320... that is pathetic IMO and a waste of money.

I wouldnt be happywithout 390 rwp, since i could get 320 out of a stock block 302 with aluminum heads

My friend makes 333/320 with a comp 274hr14 and afre 165s