Adding 100+ HP to this combo

General engine tech -- Drag Racing to Circle Track

Moderator: Team

travis
Pro
Pro
Posts: 400
Joined: Sun Mar 15, 2009 5:31 am

Re: Adding 100+ HP to this combo

Post by travis » Tue May 08, 2018 6:17 am

Carnut1 wrote:
Tue May 08, 2018 6:11 am
Has it ever been discussed the difference in sound between ported heads and unported? I thought that an improved exhaust port will go sonic and stay sonic longer. Giving it a snap. This may be way out in left field but it was the early 90's. Thanks, Charlie
It certainly does...I just don’t have time right now to tackle another long drawn out project.

RevTheory
Guru
Guru
Posts: 3847
Joined: Thu Sep 04, 2014 6:45 am

Re: Adding 100+ HP to this combo

Post by RevTheory » Tue May 08, 2018 8:29 am

This may be a call for a Bootlegger or Thumpr cam. The car will like the tighter centers and he'll like the exhaust note. What do you think?

groberts101
Guru
Guru
Posts: 1877
Joined: Sat Mar 08, 2008 3:08 pm
Location: Minneapolis

Re: Adding 100+ HP to this combo

Post by groberts101 » Tue May 08, 2018 9:12 am

RevTheory wrote:
Tue May 08, 2018 8:29 am
This may be a call for a Bootlegger or Thumpr cam. The car will like the tighter centers and he'll like the exhaust note. What do you think?
From a spec standpoint I like the bootleggers more aggressive lobe profile than the Thumprs "listen to my badass motor even though it won't run any decent numbers" stuff.. but why prematurely bleed off cylinder pressure just for the sake of sound when all one has to do to get increased lope is simply turn the idle down a tad more?

The smaller "better matched to his gear/weight" cam will clean up a bit of the overlap(which is some of his problem here killing throttle response and low speed torque output anyways) and allow more manifold vac at lower idle to be used without hurting the IFR related circuits and booster response as much. Might not sound as ratty but it will be closer without all the nasty side affects. JMO

If he does a head/manifold/cam swap on this thing it will be night and day on the street even if the car only nudges towards lower 13's

RevTheory
Guru
Guru
Posts: 3847
Joined: Thu Sep 04, 2014 6:45 am

Re: Adding 100+ HP to this combo

Post by RevTheory » Tue May 08, 2018 9:18 am

I'm just throwing out an idea because it sounds like he wants a shelf grind and I think the engine will respond more favorably to the earlier IVC than it will negatively to the earlier EVO.

randy331
Guru
Guru
Posts: 2891
Joined: Mon Dec 04, 2006 7:30 pm
Location: N.W. MO.

Re: Adding 100+ HP to this combo

Post by randy331 » Tue May 08, 2018 9:40 am

Why use a shelf cam ?

Comp Cams will grind whatever you want for the same price.

I just recently used the thumper lobes on a custom grind.

For the OP combo. Ditch the 601 heads. They aren't worth doing anything to.
A set of 062 - 906 vortecs will run a lot better.
A dual plane intake
A set of these headers will help.
https://www.summitracing.com/parts/dte- ... gLY4PD_BwE

Randy

cab0154
Pro
Pro
Posts: 205
Joined: Sat Nov 12, 2011 10:09 am
Location: North Texas

Re: Adding 100+ HP to this combo

Post by cab0154 » Tue May 08, 2018 9:53 am

at that hp, it should be able to run mid to low 13s. I would work on the combo. my stock engine 94 z28 went a best of 8.38 at 84mph in the 1/8th on motor with bolt ons. 4.10s, cold air, 1.75" shorties to high flow y pipe and single 3" exhaust. it made 274rwhp at 5200.

with that cam that that combo has it will likely need more gear and converter to get the most out of what the engine has now. being that big of a cam it is also probably bleeding off a lot of compression too. at the end of the day if $ was to be spent on the engine, like others have said: heads, intake, carb (if it is a basic 4150 a lot can be had by going to a nice custom 750) and the more compression the better. i would think pretty much any aftermarket top end combo out there could get another 100hp out of it pretty easily.
"Anyone who thinks the low RPM engine will be faster just does not have as much experience as the rest of us" -The late, great Joe Sherman.

David Vizard
Guru
Guru
Posts: 1266
Joined: Thu Jan 15, 2015 12:19 pm

Re: Adding 100+ HP to this combo

Post by David Vizard » Tue May 08, 2018 4:50 pm

travis wrote:
Sat May 05, 2018 1:13 pm
Not my car, or my build...just helping someone out.

357 sbc, unported 601 heads with stock 1.84/1.50 valves, 3 angle valve job, screw in studs, guide plates, and comp 986-16 springs, forged dished stock replacement style pistons, approx 9.7 compression, old SSI hft 302/302 advertised, 246/246@.050, .509/.509 lift, 108 lsa, 103 ica. Weiand 7546 with divider plate installed, 750dp Holley. 1 3/4” headers with full length 2 1/2” exhaust and flowtech terminators (sounds really good).

Car is a 1980 Camaro, TH350 with B&M 3000 holeshot converter, 3.42’s/posi, 235/60-15 street tires, and weighs about 3800 with him in it.

I did some fiddling with the timing, advance curve, and jetting. Best 1/4 mile is 14.01@97.35. The car will barely spin the tires on the street. It is a near daily driver and will not see the strip much at all.

The owner was nearly sick when the best it would do is 14.0’s...so much so that he yanked the engine and had it dyno’d. I don’t have the whole pull in front of me but it peaked 327hp at 5900, 344 lbs-ft at 4300 iirc. It pulls cleanly to 7000 but is seriously lacking in torque...especially for a 3800 pound car.

I’m sure gearing and head porting would make a huge difference, but the gears are fairly new and won’t be changed. He wants high 12’s on sticky tires and to be able to melt the street tires at will. Suggestions on how to approach this for under $1200-1500?

Fwiw, he loves the way it sounds, so he is reluctant to change the cam, but I don’t think I’ll have to twist his arm too hard
Without spending any big money the right cam plus a moderate amount of head work - say bigger valves and a PP job plus an increase in CR could bring the motor up to about well over 400 lbs-ft and 400 hp. I am guessing the cam is probably one of those useless 112 LCA deals. If so your guy should not hang on to this cam as it is the biggest hold up in the spec.
DV
DV
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.

DrillDawg
Expert
Expert
Posts: 959
Joined: Tue Jul 06, 2010 11:03 am

Re: Adding 100+ HP to this combo

Post by DrillDawg » Tue May 08, 2018 4:58 pm

Spec. a can using your 128 rule, show them trolls.
BORN RIGHT THE FIRST TIME

David Vizard
Guru
Guru
Posts: 1266
Joined: Thu Jan 15, 2015 12:19 pm

Re: Adding 100+ HP to this combo

Post by David Vizard » Tue May 08, 2018 5:09 pm

DrillDawg wrote:
Tue May 08, 2018 4:58 pm
Spec. a can using your 128 rule, show them trolls.
Better yet let one of my readers or the guy concerned spec it. It can't be hard -by the time my daughter was 16 she had been speccing cams for her builds for 2 years. She even speced the cam for the very widely read popular Hot Rodding magazine story entitled 'The Sledgehammer'

If this cam cannot be specced with the 128 method by a third party then I have failed in my primary goal of putting forward a simple method of getting the job done.

DV
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.

DrillDawg
Expert
Expert
Posts: 959
Joined: Tue Jul 06, 2010 11:03 am

Re: Adding 100+ HP to this combo

Post by DrillDawg » Tue May 08, 2018 5:20 pm

Show and tell time.
BORN RIGHT THE FIRST TIME

RevTheory
Guru
Guru
Posts: 3847
Joined: Thu Sep 04, 2014 6:45 am

Re: Adding 100+ HP to this combo

Post by RevTheory » Tue May 08, 2018 5:28 pm

DrillDawg wrote:
Tue May 08, 2018 5:20 pm
Show and tell time.
Several of us have been doing it for years. That is until a couple of guys started blowing up threads and getting them locked.

GARY C
Guru
Guru
Posts: 4613
Joined: Tue May 14, 2013 10:58 pm

Re: Adding 100+ HP to this combo

Post by GARY C » Tue May 08, 2018 5:38 pm

David Vizard wrote:
Tue May 08, 2018 5:09 pm
DrillDawg wrote:
Tue May 08, 2018 4:58 pm
Spec. a can using your 128 rule, show them trolls.
Better yet let one of my readers or the guy concerned spec it. It can't be hard -by the time my daughter was 16 she had been speccing cams for her builds for 2 years. She even speced the cam for the very widely read popular Hot Rodding magazine story entitled 'The Sledgehammer'

If this cam cannot be specced with the 128 method by a third party then I have failed in my primary goal of putting forward a simple method of getting the job done.

DV
Cam specs in OP says 108, installed on a 103.

F-BIRD'88
Guru
Guru
Posts: 6103
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: Adding 100+ HP to this combo

Post by F-BIRD'88 » Wed May 09, 2018 12:38 pm

The real compression ratio is not as high as it should and could be.
Unless you can do it at VERY low cost, the 601 heads are not worth investing ( work or money) in. Sell them to a street stocker dirt guy and buy decent aluminum heads.
Every thing you do to reduce vehicle weight is a BIG plus. Extra points for weight reduction in front of the driver. Need to shed 600 lbs. These cars can be lightened up.

F-BIRD'88
Guru
Guru
Posts: 6103
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: Adding 100+ HP to this combo

Post by F-BIRD'88 » Wed May 09, 2018 1:01 pm

I built a flat top 355 a few years back with 993 heads and just blended the bowls and did a nice valvejob. With a performer rpm airgap and a 650 Holley it made 364 hp at 5400 rpm and 416 lb ft of torque at 4100 rpm. In a 1971 el Camino with 3.55 gears and way to tight of a converter it ran 8.41 at 84 mph in 1/8 and a 13.14 at 104 in the 1/4. It's a great cam for builds like that with around 9.5:1 compression.

If your El Camino had had 4.56 gears in it it would have run strong 12sec et's
Your El Camino is actually a bit lighter weight than this 80's camaro.
They are tanks. This should be addressed.

Note the dyno test peak torque rpm. Get a converter that has this stall speed.
This (The posters) engine is very weak at 3000 rpm (stall speed)
A air gap dual plane manifold is a easy fix. The weiand 7546 accelerator intake
is very weak at 3000 rpm and so is the cam.

F-BIRD'88
Guru
Guru
Posts: 6103
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: Adding 100+ HP to this combo

Post by F-BIRD'88 » Wed May 09, 2018 1:43 pm

The compression ratio is too low. It can likely be fixed simply by swapping the head gasket for a felpro .015 steel shim had gasket. CC the heads they are not all 53cc.
The heads will need full effort home porting. Block the twinned egr ports passages so the center ex ports do not "crosstalk". You can get 228-230cfm 150-160ex out of the heads with the stock valves + full Home porting and a 30deg hand back cut.
The chamber needs a LOT OF deshrouding even with the stock valves in it.
CarNut1 will show you how.
you need to get serious with the grinder on these.

They are about 188 cfm in 130cfm ex now That and the egr port cross talk is a BIG power cork
Much better cam for this COmp cams CS270b-6 235-242 106/102 .495 .507 .020 .022
After the head work is done. Combine with a dual plane HIrise intake.
Your intake sucks on this type of motor.

This same cam will also work great on a aftermarket aluminum heads like the ATK profilers.
If he likes the current cam he will like this one even better.
Swapping to a dual plane hi rise intake (Performer RPM or clone) will have a profound effect.
Last edited by F-BIRD'88 on Wed May 09, 2018 2:03 pm, edited 1 time in total.

Post Reply