Dyno Results: MMS LS7 heads ERL 427 build has begun
#21
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From: Melbourne Beach FL
Build is finally to the point where Erik just fired her up. Definitely looking different now under the hood.
Lots of little delays along the way. LS7 fuel rails turned out to be a special order. Lots of rewiring and re-plumbing to straighten out years of modifications. Moved the oil pressure gauge sensor to a braided hose from the solid mount. Braided transmission line was rubbing in a spot and needed replacing as well.
...and for the latest. The LS7 fuel rails moved the coils out and blocked the breather in the oil fill. ...the problem was to find a replacement breather that would work with my Nasty Performance valve covers and its the odd ball 1 1/4-12 thread on the filler hole. Well we couldn't find one so Back Street ended up making one. So it started out as a stock bar.
... ended up paired with a Moroso filter to match the one on my drivers side catch can.
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Lots of little delays along the way. LS7 fuel rails turned out to be a special order. Lots of rewiring and re-plumbing to straighten out years of modifications. Moved the oil pressure gauge sensor to a braided hose from the solid mount. Braided transmission line was rubbing in a spot and needed replacing as well.
...and for the latest. The LS7 fuel rails moved the coils out and blocked the breather in the oil fill. ...the problem was to find a replacement breather that would work with my Nasty Performance valve covers and its the odd ball 1 1/4-12 thread on the filler hole. Well we couldn't find one so Back Street ended up making one. So it started out as a stock bar.
... ended up paired with a Moroso filter to match the one on my drivers side catch can.
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Filter side:
#24
Very nice build first of all,I love these build threads! I'm wondering about the heads and I know flow #'s aren't everything and it's the whole combo package.I guess most of the time more air flow will get you more HP if it's matched.I'm wondering about having a set of heads that flow 400 plus on a street car?I'm building a track only 403 with nitrous and I wished I had a set of these,,,hopefully down the road.I mean those heads are something I would of thought would be on a race engine and not a street car.I'm just trying to learn so it may be a dumb question but I just thought it would be overkill for a street car??? I know Tony knows his stuff and I just wanted to learn.
Thanks for any input again killer build
Thanks for any input again killer build
#25
Very nice build first of all,I love these build threads! I'm wondering about the heads and I know flow #'s aren't everything and it's the whole combo package.I guess most of the time more air flow will get you more HP if it's matched.I'm wondering about having a set of heads that flow 400 plus on a street car?I'm building a track only 403 with nitrous and I wished I had a set of these,,,hopefully down the road.I mean those heads are something I would of thought would be on a race engine and not a street car.I'm just trying to learn so it may be a dumb question but I just thought it would be overkill for a street car??? I know Tony knows his stuff and I just wanted to learn.
Thanks for any input again killer build
Thanks for any input again killer build
Check out some of the builds/numbers over on CorvetteForum.
#26
Thanks for the input,I've always messed with SBF stuff.My last combo was a NA Brodix Neal headed 850HP combo,ran 5.60's in the 1/8th with my 89 Fox Body GT (had it since was new).I'm trying to research and learn this LS stuff,gotta a 403 with GMPP LS3's with a carb and nitrous gonna start out with and go from there.
Thanks again
Thanks again
#27
Very nice build first of all, I love these build threads! I'm wondering about the heads and I know flow #'s aren't everything and it's the whole combo package. I guess most of the time more air flow will get you more HP if it's matched.
I'm wondering about having a set of heads that flow 400 plus on a street car?......
I'm wondering about having a set of heads that flow 400 plus on a street car?......
With Mamo's Trick Flow heads, the intake port is only 265cc....and the intake valve size is only 2.200".....you're talking serious airflow velocity here, and that's a VERY good thing!
Not only will these heads work well on a stroker, street car engine but they'll most likely work on an unmodified LS3 block, too.
Now.....if the heads need 285+cc intake ports and intake valves the size of dinner plates to get that 400 cfm......THEN.....you'll have issues at lower RPMs and with engines with stock(ish) displacements ( <6.2L ).
KW
#28
Heads that flow 400+ cfm on a street car is a non-issue if done right.
With Mamo's Trick Flow heads, the intake port is only 265cc....and the intake valve size is only 2.200".....you're talking serious airflow velocity here, and that's a VERY good thing!
Not only will these heads work well on a stroker, street car engine but they'll most likely work on an unmodified LS3 block, too.
Now.....if the heads need 285+cc intake ports and intake valves the size of dinner plates to get that 400 cfm......THEN.....you'll have issues at lower RPMs and with engines with stock(ish) displacements ( <6.2L ).
KW
With Mamo's Trick Flow heads, the intake port is only 265cc....and the intake valve size is only 2.200".....you're talking serious airflow velocity here, and that's a VERY good thing!
Not only will these heads work well on a stroker, street car engine but they'll most likely work on an unmodified LS3 block, too.
Now.....if the heads need 285+cc intake ports and intake valves the size of dinner plates to get that 400 cfm......THEN.....you'll have issues at lower RPMs and with engines with stock(ish) displacements ( <6.2L ).
KW
Last edited by cbunn; 02-22-2018 at 12:59 PM.
#30
I'm running 60lb/hr injectors on a 416. Are those 42s enough for that monster?
I don't care for that particular cam, but w/that intake will probably make a very streetable setup. Going to be interesting to see how it comes out.
I don't care for that particular cam, but w/that intake will probably make a very streetable setup. Going to be interesting to see how it comes out.
#32
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Erik isn't liking the oil pressure from Tony's LSA pump and told me today he thinks a VVT pump is the way to go. I'm not really familiar with a VVT so I have some research to do. Anybody knowledgeable on this pump?
Last edited by GTO1_OHIO; 02-23-2018 at 06:12 PM.
#33
The ls2/ls3 top end engine I pulled out for my new build has a VVT pump, and doesn’t have near the pressure that this new build has.
Not sure if this helps you or not...
#34
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With the pump tony sold me, I’m at 70 cold idle, jumps to 90 if I touch the throttle. 40 hot idle, 60 cruising. I’ve got more pressure than I need, which wastes power.
The ls2/ls3 top end engine I pulled out for my new build has a VVT pump, and doesn’t have near the pressure that this new build has.
Not sure if this helps you or not...
The ls2/ls3 top end engine I pulled out for my new build has a VVT pump, and doesn’t have near the pressure that this new build has.
Not sure if this helps you or not...
Last edited by GTO1_OHIO; 02-23-2018 at 07:42 PM.
#35
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Haven't updated in a while but the Melling 10355 High Volume/High Pressure Oil Pump For AFM-Equipped LS Engines did the trick and the oil pressure is back to normal.
Oil pressure 37 psi, oil temp 174 degrees in recent video, running Lucas 10w40 Semi-Synthetic. Now just waiting on the tune to be completed.
Oil pressure 37 psi, oil temp 174 degrees in recent video, running Lucas 10w40 Semi-Synthetic. Now just waiting on the tune to be completed.
Last edited by GTO1_OHIO; 04-12-2018 at 04:40 PM.
#37
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From: Melbourne Beach FL
545.59 rwhp 478.47 rwtq NA
Fell a little short of the 550-600 goal but I know the reverse dome pistons (18CCR )are hurting me some, that plus the new cam isn't very aggressive, as was pointed out above. So there's some future improvements that can be made in those areas.
Here's a run during tuning by Erik Johnson at Backstreet Performance, Medina Ohio
and the final results from last night
Fell a little short of the 550-600 goal but I know the reverse dome pistons (18CCR )are hurting me some, that plus the new cam isn't very aggressive, as was pointed out above. So there's some future improvements that can be made in those areas.
Here's a run during tuning by Erik Johnson at Backstreet Performance, Medina Ohio
and the final results from last night
Last edited by GTO1_OHIO; 04-21-2018 at 06:58 AM.
#38
So in summary the big changes were Tony's heads/rockers, his MSD intake a cam change (which was very similar to the one you had already), lifter change and a bigger TB. Looks like you picked up 70 hp at peak and 100 hp at like 6500 rpm without loosing any TQ - very nice.
#40
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Yeah, also easy to see that he Mamo ported AFR 205s were chocking the bigger block; torque falling off at 5000, hp falling off at 6000. The 205s did great on my original LS1 block. We had run it up to 7200 rpm and ran 11.49 at 126. As well built as those 205s are, it was obvious on the track that the 205s couldn't do the same for the 427. Tony's LS7 heads have more unleashed potential than my current build shows.