Generation IV Internal Engine - Some new results for my 455.

My last set up ended up with some ring issues, while it was apart I made some changes. In the process it picked up 70hp.

What's in it.

REDs LS7 MID block. 4.198 bore.
Callies 4.125 Magnum crank
Compstar H Beam 6.125 rods
Wiseco pistons and ring package.
Morel lifters
PI 275 Cathedral port heads
Ported and modified Harrop 55mm intake
Kooks 1 7/8 headers
Cam 255 263 .67x lift 110

Big Stuff 3 to control it.

What did it do.

http://www.streetfire.net/video/ls7-455-with-a-harrop-part-2_2290861.htm


https://blu2.storage.live.com/items/6FAE0EC71CEF8D21!2564:Scaled1024/Dyno%20graph%20705hp.jpg

https://blufiles.storage.live.com/y1pCcYiBVElCyq9pLCrSge6DyLZFHOzVm-iP7KT3AIszuaTV2V0ljdwXkknIH-gXXjojfaZ-nZKZmbygKOkVnS6EQ/Dyno%20Data.jpg

Thanks for the help and support from:

Wildgoose Performance
Erik Koenig
Wade Stevens
Stage 7
RobZ

Congrats Rampant! It sounds sweet. I am looking fwd to hearing your impressions once you have it in the car and start driving it.

Love how people are using ITB's more and more now.....I tried saying two years ago that its the way to make the real power........not many people listened......it was so obvious too.........FUNNY!

Nice power "Rampant".......


.

Love how people are using ITB's more and more now.....I tried saying two years ago that its the way to make the real power........not many people listened......it was so obvious too.........FUNNY!

Nice power "Rampant".......


.

I have been running the Harrop since 2008, it is only making some descent power now though. Needed porting, different heads and a different cam. Now it is reasonable power. The Harrop does not flow as well as you'd think. It only flowed 283 CFM. We ported it and I designed new throttle shafts.

https://blu2.storage.live.com/items/6FAE0EC71CEF8D21!301:Scaled1024/IMGP2876.jpg

https://blufiles.storage.live.com/y1pIqzjUO5SYYCpnTsWrDTR01BgF5xrKtIvVWQK53dclFolhhZ BxgtDo7NTuDcbxsRvBMYFEf5PbMQ/IMGP2888.jpg


What I do love about the intake is the throttle response, zero hesitation tipping in or lifting off. Makes a huge difference in the cars handling.

Good stuff Rampant! ITB's ftw!!! I've got a couple red "x's" though....I thought I heard 700 in the video. Numbers?

MAN, I cant wait to get mine on the dyno!

Good stuff Rampant! ITB's ftw!!! I've got a couple red "x's" though....I thought I heard 700 in the video. Numbers?

MAN, I cant wait to get mine on the dyno!

705/663, the very first full run was 695, so it was really close out of the gate and 700 kept teasing us. We had one at 699.6 peak and I had seen 700 on the screen but it must not have been a data point. So that run in the video had several 700s showing. I knew it had to have broken it then. I also liked that this motor like my LS2 412, seemed to like to be hot. That run was at 160 but was about the third pull in 10 minutes. We tired one with the coolant at 130 and it dropped to 695 again. So that is a good thing, I need to order up a 160 T Stat.

Do you still see red Xs? I just changed the permissions. It was those with a link, but sometimes it does not work. So it is fully opened now. It should be a graph and a data list.

Man. 90 degrees in the dyno room. Hot...

When are you getting it in the car?

Man. 90 degrees in the dyno room. Hot...

When are you getting it in the car?

90 was cool, last Saturday I put the intake on and wired the Big Stuff, it must have been 100+ then, I was totally soaked then. Their engine building room has AC, but not the dyno room.

It was nice and cool the first time with the 455 back in Dec 2008!

http://usera.imagecave.com/Rampant/Document%20(4).jpg

I will get started putting it in likely next weekend or the week after. More than likely September before I am out and rolling with a dyno tune.

705/663, the very first full run was 695, so it was really close out of the gate and 700 kept teasing us. We had one at 699.6 peak and I had seen 700 on the screen but it must not have been a data point. So that run in the video had several 700s showing. I knew it had to have broken it then. I also liked that this motor like my LS2 412, seemed to like to be hot. That run was at 160 but was about the third pull in 10 minutes. We tired one with the coolant at 130 and it dropped to 695 again. So that is a good thing, I need to order up a 160 T Stat.

Do you still see red Xs? I just changed the permissions. It was those with a link, but sometimes it does not work. So it is fully opened now. It should be a graph and a data list.

X's fixed! Thanks! Great curve and nice peak rpm. Real boulevard bruiser! :devil:

Nicely done sir. You sure are one determined mofo I give you a lot of respect for pushing through all them hurdles to reach your goal. It sure would be nice to see 600whp eh? It'll be close....

Wow...nice power.

What is the compression?

Wow...nice power.

What is the compression?

Thanks.

A nice safe 11.2:1

Nicely done sir. You sure are one determined mofo I give you a lot of respect for pushing through all them hurdles to reach your goal. It sure would be nice to see 600whp eh? It'll be close....

Thanks.

I knew it had it in it, but just kept getting bum luck. I think if the pistons and rings had shown up as ordered, it may have had 725-730 in it. I am happy with the 705, it will make more as it breaks in too.

have you got this running in the car yet? how much rwhp?
what problems and modifications did you have to do you were saying with the ITB's?

have you got this running in the car yet? how much rwhp?
what problems and modifications did you have to do you were saying with the ITB's?

No not in the car yet. Fighting with paint on the inner fenders currently.

No real issue with the Harrop, though it flowed poorly as cast. 283cfm. So we ported it and I had a set of new throttle shafts made. I flowed close 330cfm when we were done. The shafts were worth 12cfm alone.

https://blufiles.storage.live.com/y1phlaO0BxjjnQgXa9JFJ4qPp_Rh-LpB9R2TsOwnA_d9I6gZ-PlnZxK16fd6MAJkUOvGDMceCEwWRw/100_1267.jpg

https://blufiles.storage.live.com/y1pa_7AtsUfQrLGXTc0G1dmBuElGpsR18Xqk4uCJBOupvt9SJQ V0447thgK5XQc498oAZRkQRJaG_s/100_1269.jpg

The issues I had were mainly with piston rings falling apart. I had 71% leak down on one cylinder and 22 on another.

https://blu2.storage.live.com/items/6FAE0EC71CEF8D21!1397:FullScreen/IMGP3534%20close%20up.jpg


It never seemd to perform correctly and had high oil temps. Still trapped 125mph the week before that picture though.

I bought the heads and cam from Stage 7 as he had great success with a Harrop on them and I only had 11 fewer cubes. So we were confident it would work well. I think 2" headers would have helped, but it has nice low end torque for street and autocross use.

any idea what the 283/330cfm is in comparison to something like a fast 102mm

Also im not sure how it works but if your intake is flowing 330cfm does that equal total air flow of 330x 8 =2640
which would still make a high rise intake marcella with 2x 2000cfm throttle bodies carb style efi flow alot better?

like this:

http://www.youtube.com/watch?v=r0oodHrDAfc

http://www.youtube.com/watch?v=QA-uszLNcsU

What we noticed on the flow bench was that the inline restriction was not the total flow. When the heads flowed 330cfm and the intake 283, and both bolted together it showed a flow of 305. So it seemed to find the aproximate middle point, as though the heads were able to pull on the intake. That said the higher you can get every link will offer an improvement in the engines peak potential, but you may sacrifice the bottom end in going to big.

I think there is a lot to be said for a well matched set of components and I am not the guy to talk about that theory, there are much better on here than I.

im thinking about some itb's for my GTO 454 but if the twin 2000cfm like in the video is better.....umm i still dont know, which one do you think is best for highest hp drag racing?

im thinking about some itb's for my GTO 454 but if the twin 2000cfm like in the video is better.....umm i still dont know, which one do you think is best for highest hp drag racing?

The twins would likely be over kill and require major mods to fit under the hood. I doubt the idle would be all that low or good either. Great for all out drag applications though.

The ITB intake tames a big cam. If you like cam lope, it is not the intake for you. It is one of the reasons I wanted it. On the street, people will have no idea what you have. Mine idles at 750rpm and likley could go lower, but I figured that was low enough. Considering I have a 253/266 cam that is a pretty mild idle.

yeah mine with a fast 102/102 idles at 875rpm.

Sweet build bro, the torque is what really shows on your build. I had alot of the same issues and just worked through them to get where i'm at. Looked like you did the same and came out with a winner! Hopefully you can join the 600+ to the rear wheels club. It ain't easy let me tell ya :bang:

I find it very interesting that we have very similar engines, almost the same displacement, (except mine has a smaller bore, longer stroke) I have less cam duration (251 @ .050"), we make almost identical power, but my engine with a Fast 102 makes peak power higher at 6300-6400? That tells me your cam is either advanced too much (mine was a 115 lsa on a 114 icl) or that Harrop is still restrictive on that size engine even after porting. I also find it interesting that I lost 100 lb/ft of torque going from engine dyno to chassis dyno (630 tq vs 530 tq), yet Stage 7 made 630 tq at the tires, that would suggest 730 tq at the crank, just doesn't add up in my mind.

Thanks for sharing, and sorry to the OP for the highjack!


BTW, I've seen 502's make less than 700 hp, you would be getting it done to make 800 hp on pump gas with a hyd roller cam and would require something like a Mast intake or a Holley LS3 intake with dual TB's and some large heads flowing over 400.

http://i67.photobucket.com/albums/h290/Brian_Tooley/454LSDyno.jpg



I think 3 things held my motor back a little. Rings were not as I ordered, so it has a regular scraper 2nd ring, not the Napier I ordered. I asked for a full dish piston and got a quench pad. When they were ordered, the ring pack as ordered was supposed to be available, that changed mid order with no notice, as did the engineer who changed the full dish to a quench pad. They did offer to exhange the pistons, but there was nothing to be done with the rings and was going to be a couple months. 1 7/8" headers not 2" were used. These things were different from Stage 7's. I also do not think it was fully broken in on the dyno, there might be another 5-10 there as well.

I also used 1 7/8", old style Kooks from 2005. I am getting 2" now with the newer style merge on them. So it did not have big dyno headers on it, just my old faithfulls from my 412.

I may or may not lose torque with the bigger header, but it will likely carry a little better up top. My power curve and rpms look identical in shape to Stage 7s, just 40-50 hp lower. I have a 6speed so I hope it only loses 85-90hp, but it is making 70hp more than it did with a smaller cam. :D So I am happy.

If I make the assumption that Stage 7 made 750hp fw, and use 457ci/468ci x 750hp, it gives 732. So I am off by 27hp, which is just 3.5%.

We all know dyno's vary too, so who knows for sure.

What I really like about the Harrop is the throttle control and idle qualities. Much different than my Fast 90 was. I like to make the car turn even more than I do drag racing.:D I know for a fact the Harrop does not flow well as cast. We gained nearly 40cfm with some porting and throttle shafts. Still only at 330cfm after all that.

My motor is not in the same league as these other big cube motors. It has lots of good parts, makes pretty good power and with loads of mid range torque. It should make a good streetable motor.

I used 1 7/8" headers as well.

I used 1 7/8" headers as well.

I would think I will need 2" to even approach the flow of the 245s exhaust ports. Let alone your nitrous version. The intake side is the strong point of the Mast head, with the extra 30cc's that is not surprising though.

In fact the order should be placed by end of day for the new headers.

It seems a number of places have dyno headers which are far bigger than the ones actually going to be used. Where I went, they only have SBC and BBC stuff so we used my 2005 Kooks headers that do not have a high velocity merge, but only the standard header collecter with the spike. They are in perfect condion no dents or anything, but it seems the Merge does help make a little more power.

https://byfiles.storage.live.com/y1pb5zWlmPQN-qvlkhzsOwCw14YLyURtnQiocBA6UMPcMsbemuEW6hzwnnza1xS UiR4L8oTJ9CaJVg/IMG_6526.JPG

Brian, which headers do you have?

Your motor did carry the torque a little longer than mine, but was lagging 30ft.lbs in the mid range. Top and bottom of the 3500-6500 were nearly the same.

I also think a little tuning will fatten up my 4.3k-4.7k range. It got pretty rich in there. I noticed that Stage7's tune did the exact same thing and same place.