Adding 100+ HP to this combo

General engine tech -- Drag Racing to Circle Track

Moderator: Team

F-BIRD'88
Guru
Guru
Posts: 6001
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: Adding 100+ HP to this combo

Post by F-BIRD'88 » Thu May 10, 2018 12:32 pm

The real compression ratio of this engine based on what you have now posted about it is 8.94:1 with a .040" gasket. Needs to be 10.50:1.

F-BIRD'88
Guru
Guru
Posts: 6001
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: Adding 100+ HP to this combo

Post by F-BIRD'88 » Thu May 10, 2018 1:12 pm

Here is a engine where you could apply David Vizards 128 formula to the cam selection
and drag test it as is against the current camshaft.

My math suggests a 104.4 LSA camshaft. I'd also suggest knocking back on the duration too to pump lots of torque into this slug.
104 to 105 LSA installed a bit advanced say 268 ish to 275 ish real seat to seat lash point running duration.
I suggest a short duration tight lash style solid lifter cam. (Comp cams MH series or XTQ series or extreme energy solid lobes series on the suggested LSA.)
Move it around a bit and play with the lash a bit to find the sweet spot
and let the ET slip speak.

As DV has said the real value is when a 3rd party has success using his simple 128 formula to get a better cam choice. Might end up with a strong 13sec performer with a good torque curve on this car engine as is. or with other very cheap changes. (used RPM intake)

F-BIRD'88
Guru
Guru
Posts: 6001
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: Adding 100+ HP to this combo

Post by F-BIRD'88 » Thu May 10, 2018 1:59 pm

You'd also want to test some collecter extensions
to let the re cammed engine be all it can be.
pretty cheap mod.

As I said you could use the current cam with added solid lifters to adjust the real running seat to seat duration and net valve events and real verified installed position to get as close to the suggested new valve events of the new 128 formula cam as possible and see if the engines/cars perf (et slip) moves in the right direction.. Again a cheap mod.

rfoll
Guru
Guru
Posts: 2175
Joined: Mon Jan 11, 2010 12:44 pm
Location: St. Helens, OR

Re: Adding 100+ HP to this combo

Post by rfoll » Thu May 10, 2018 4:38 pm

travis wrote:
Thu May 10, 2018 8:57 am
I’m sure 4.56’s would be a lot of fun at 80mph keeping up with traffic 🙄

Doesn’t matter anyway...this thing is junk. Turns out his “425hp street/strip” eBay special is nothing more than a cheaply built stock replacement cast dished pistoned 2 bolt 357 with pistons .048” in the hole, 58cc chambers, barely over 9-1 compression, and a big cam. Judging by the bearings and main caps, it clearly wasn’t happy being zinged up to 7k rpms with the stock crank and rods.

The guy just left here with his stuff...not a very happy camper I might add.
One of my friends acquired an ebay 383 that was supposed to be built with Scat crank and rods. We pulled the pan and found a stock crank and 305 rods. The roller tips on the shiny blue rockers were beat to death.
So much to do, so little time...

gmc406
Member
Member
Posts: 149
Joined: Wed Nov 14, 2007 12:00 am
Location: Sask Canada

Re: Adding 100+ HP to this combo

Post by gmc406 » Sat May 12, 2018 11:00 pm

rfoll wrote:
Thu May 10, 2018 4:38 pm
travis wrote:
Thu May 10, 2018 8:57 am
I’m sure 4.56’s would be a lot of fun at 80mph keeping up with traffic 🙄

Doesn’t matter anyway...this thing is junk. Turns out his “425hp street/strip” eBay special is nothing more than a cheaply built stock replacement cast dished pistoned 2 bolt 357 with pistons .048” in the hole, 58cc chambers, barely over 9-1 compression, and a big cam. Judging by the bearings and main caps, it clearly wasn’t happy being zinged up to 7k rpms with the stock crank and rods.

The guy just left here with his stuff...not a very happy camper I might add.
One of my friends acquired an ebay 383 that was supposed to be built with Scat crank and rods. We pulled the pan and found a stock crank and 305 rods. The roller tips on the shiny blue rockers were beat to death.
Did you go after the seller? That’s horse sh!t.

Too bad for your friend.

rfoll
Guru
Guru
Posts: 2175
Joined: Mon Jan 11, 2010 12:44 pm
Location: St. Helens, OR

Re: Adding 100+ HP to this combo

Post by rfoll » Sun May 13, 2018 11:05 am

He got the motor from a friend who had bought it and let it sit for several years, much too late for any reparations from the eBay seller. Fortunately the friend was good enough to give him back some of his money in exchange for the bad rotating assembly. He kept the block, AFR heads, and Lunati cam.
So much to do, so little time...

Post Reply