I dynod my 355 tested several things I am sharing

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MTENGINES
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Re: I dynod my 355 tested several things I am sharing

Post by MTENGINES » Sat Oct 21, 2017 4:36 pm

kimosabi wrote:
Sat Oct 21, 2017 4:17 pm
"For instance 241cc should be way too big "

How did it perform under 4000rpm, as that is the common argument on big ports.
Who cares. The dyno pulls were probably started at 5500rpm.

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Re: I dynod my 355 tested several things I am sharing

Post by Rick360 » Sat Oct 21, 2017 4:40 pm

Nice running engine Eric and interesting tests. =D>

Thanks for sharing.

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Re: I dynod my 355 tested several things I am sharing

Post by ptuomov » Sat Oct 21, 2017 5:27 pm

Thanks for sharing
[b]Paradigms often shift without the clutch[/b] -- [url]https://www.youtube.com/watch?v=cxn-LxwsrnU[/url]

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Re: I dynod my 355 tested several things I am sharing

Post by kimosabi » Sat Oct 21, 2017 5:51 pm

MTENGINES wrote:
Sat Oct 21, 2017 4:36 pm
kimosabi wrote:
Sat Oct 21, 2017 4:17 pm
"For instance 241cc should be way too big "

How did it perform under 4000rpm, as that is the common argument on big ports.
Who cares. The dyno pulls were probably started at 5500rpm.
Well the guys building street engines would care. Usually the big port arguments come as a result of discussing driveability and low end response. I can see the engine here is a race spec deal but the "too much head" arguments I have seen, most of them are about street engines.

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Re: I dynod my 355 tested several things I am sharing

Post by GARY C » Sat Oct 21, 2017 5:54 pm

I would love to post pics but without photobucket I have no idea how.
If you have the photos on your computer, click attachments tab down below, then click add files, go to the file and picture on you computer and dbl click the photo and wait for it to load. you can click preview button next to submit and see if it works. If it posts sideways you need to reduce picture on your computer and start over.

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Re: I dynod my 355 tested several things I am sharing

Post by GARY C » Sat Oct 21, 2017 5:55 pm

kimosabi wrote:
Sat Oct 21, 2017 5:51 pm
MTENGINES wrote:
Sat Oct 21, 2017 4:36 pm
kimosabi wrote:
Sat Oct 21, 2017 4:17 pm
"For instance 241cc should be way too big "

How did it perform under 4000rpm, as that is the common argument on big ports.
Who cares. The dyno pulls were probably started at 5500rpm.
Well the guys building street engines would care. Usually the big port arguments come as a result of discussing driveability and low end response. I can see the engine here is a race spec deal but the "too much head" arguments I have seen, most of them are about street engines.
If you were building a street engine you would not use 241cc heads on a 355.

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Re: I dynod my 355 tested several things I am sharing

Post by paulzig » Sat Oct 21, 2017 6:21 pm

kimosabi wrote:
Sat Oct 21, 2017 5:51 pm


Well the guys building street engines would care. Usually the big port arguments come as a result of discussing driveability and low end response. I can see the engine here is a race spec deal but the "too much head" arguments I have seen, most of them are about street engines.
Somehow I doubt this engine is going to suffer with poor low end response, on the street it would most likely destroy tyres at the slightest throttle movement.

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Re: I dynod my 355 tested several things I am sharing

Post by MTENGINES » Sat Oct 21, 2017 7:24 pm

GARY C wrote:
Sat Oct 21, 2017 5:55 pm
kimosabi wrote:
Sat Oct 21, 2017 5:51 pm
MTENGINES wrote:
Sat Oct 21, 2017 4:36 pm


Who cares. The dyno pulls were probably started at 5500rpm.
Well the guys building street engines would care. Usually the big port arguments come as a result of discussing driveability and low end response. I can see the engine here is a race spec deal but the "too much head" arguments I have seen, most of them are about street engines.
If you were building a street engine you would not use 241cc heads on a 355.
Why not? I've used 300cc heads on street engines of that size.


Simply put, I have had customers not listen to me when I recommend a stall converter of let's say 4500 for the street. They know more than me and put a 2000 stall and complain because it doesn't idle right, it lugs agains the converter in parking lots etc.. they throw a new carb at it thinking it will fix it and then read on forums and decide their cam is too big. When all they had to do was use the right gear and converter. As long as the combo is matched it will work.

Some guys want their 700hp pump gas small blocks, and expect them to run like their 160hp 350 they replaced it with.

Like I said who cares what the engine does below 4000 rpm when your stall converter is at least that.

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Re: I dynod my 355 tested several things I am sharing

Post by Walter R. Malik » Sat Oct 21, 2017 7:39 pm

It is all about the combination and its intended use.
This is a good combination for any wide open throttle application ... good job.
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Re: I dynod my 355 tested several things I am sharing

Post by RAMM » Sat Oct 21, 2017 7:55 pm

WeingartnerRacing wrote:
Sat Oct 21, 2017 11:51 am
Here is the combo
355sbc
4.030x3.48
11.97 compression ratio
My ported Brodix Dragon Slayer head 241cc 2.63csa 2.08/1.6 valves hollow stem intake valve they flowed 322cfm on a 4.030 bore
Ported Brodix Bm100 intake
1000cfm Race demon carb used as gas and methanol
252/258@ 0.050 108LSA installed at 106 .780/.688 cam Hate this LSA
Best headers 1 7/8 stepped to 2inch with 3.5inch collector
No vacuum pump or evac set up.

Here is how it went and some reasons. First I built a 355 because I wanted a test engine that I wouldn't feel bad if it blew up or sucked. I had this 355 because I used it in the 2007emc. The cylinders got honed and installed longer 6inch rods and SRP proffesional series pistons with a small dome. All other parts were picked because I wanted to test things. For instance 241cc should be way too big according to the internet for a 355. I wanted to see what it would really do. I had never used this new brodix intake so why not try using it. The cam I had never used the QRI lobes so time to try that. Is methanol really that much better than gas? I wanted to find out? What about bigger headers hurting power. I had heard several things that on the internet that from previous testing hadn't shown to be correct for me. Let's just see.

The dyno actually started on a down side within 2minutes of firing it a loud squeal was heard. Shut it down and found out the roller cam button in the Cloyes timing cover had failed. Changed that and started making runs. Initially it was on 91octane Casey gas station gas. Timing was at 30degrees. First pulls were 3500-5500. When it first loaded it would slightly rattle but then went away. As the pulls kept increasing in rpm we raised the lower limit too. Then it never did it again. So that pump gas will work with this compression ratio but you have to take out timing down low. Here is a run down of tests and there changes.

Timing from 30 to 33 degrees netted about 50hp
Timing from 33 to 36 degrees netted 10hp it was left there for the rest of the testing.
I added the race gas additive to bring the octane to 98 it gained 2hp
Changed headers to 1 3/4 to 1 7/8 with a merge collector 3inch it lost 4hp. I tried different jetting it was solidly down.
Switched the race demon to methanol. (you change boosters, metering blocks, bleeds, squirters, needle and seat) It gained about 10hp and 20ft lbs of torque
Peak torque gas was 515tq@ 6100rpm
Peak torque methanol was 537.5@5900-6000rpm
Peak horsepower gas 662hp@7300rpm
Peak horsepower methanol 672.6@7400rpm

Strange thing though when it was fat on methanol to begin with it made its best torque at 542. This is always what I've observed

I made about 20 pulls 15 were between 5500-7500 rpm
I did make a couple of pulls on gas to 7800rpm it went like this(This was with the smaller headers)
7000-646
7100-649.9
7200-653.2
7300-654.8
7400-656.3
7500-656.0
7600-654.8
7700-650.9
7800-648.1

It hung in good.

It probably has a 680 in it but I had to be somewhere in the evening and called it quits. The EGTs were just starting to get to 1050

I would love to post pics but without photobucket I have no idea how.
Thankyou Eric, this is really interesting-nice job. Don't you just want to put it in something light with a 5.13 gear and try it out?

Very interesting timing on this as well as I just finished something similar- a 360 (stock stroke) Mopar project that made 550 HP @ 7000 with a SFT. J.Rob
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http://skmfxengines.blogspot.com/

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Re: I dynod my 355 tested several things I am sharing

Post by GARY C » Sat Oct 21, 2017 8:02 pm

MTENGINES wrote:
Sat Oct 21, 2017 7:24 pm
GARY C wrote:
Sat Oct 21, 2017 5:55 pm
kimosabi wrote:
Sat Oct 21, 2017 5:51 pm


Well the guys building street engines would care. Usually the big port arguments come as a result of discussing driveability and low end response. I can see the engine here is a race spec deal but the "too much head" arguments I have seen, most of them are about street engines.
If you were building a street engine you would not use 241cc heads on a 355.
Why not? I've used 300cc heads on street engines of that size.


Simply put, I have had customers not listen to me when I recommend a stall converter of let's say 4500 for the street. They know more than me and put a 2000 stall and complain because it doesn't idle right, it lugs agains the converter in parking lots etc.. they throw a new carb at it thinking it will fix it and then read on forums and decide their cam is too big. When all they had to do was use the right gear and converter. As long as the combo is matched it will work.

Some guys want their 700hp pump gas small blocks, and expect them to run like their 160hp 350 they replaced it with.

Like I said who cares what the engine does below 4000 rpm when your stall converter is at least that.
Thats the problem with the blanket term "street"

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Re: I dynod my 355 tested several things I am sharing

Post by John Wallace » Sat Oct 21, 2017 8:37 pm

Thanks for the info, Eric!

:)

How did you determine correct jetting for the alcohol?

Did you try the bigger headers with the alcohol?

:?:
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Re: I dynod my 355 tested several things I am sharing

Post by joe 90 » Sat Oct 21, 2017 9:20 pm

Not everyone drives with an auto trans.
With a manual box you want a good power band from 1000rpm to the top.

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Re: I dynod my 355 tested several things I am sharing

Post by WeingartnerRacing » Sat Oct 21, 2017 9:53 pm

John Wallace wrote:
Sat Oct 21, 2017 8:37 pm
Thanks for the info, Eric!

:)

How did you determine correct jetting for the alcohol?

Did you try the bigger headers with the alcohol?

:?:
We had o2s but I used egt. It was cold leaning it out it heated up and power came up.
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Re: I dynod my 355 tested several things I am sharing

Post by WeingartnerRacing » Sat Oct 21, 2017 9:55 pm

I plan to drive it to the track 6200rpm stall and all. It’s going in an s10
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