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290 Posts
Discussion Starter · #1 ·
Alright, posted at the very bottom is my build sheet on my motor, in case it helps.

My engine is just a few months old up here in Northern Cali. It was made at Bas Ass Racing in Sonoma, by excellent mechanic Aaron.

Anyways, lately it's been having a problem when I turn it off, sometimes it will kinda backwhine, like the tinming is a bit off. I'm sure you guys know what I'm talking about, like the car will shudder and kinda turnover in almost seemingly the opposite direction.

Well today, I had a race planned, so I wanted to tune up the car a bit. I just messed with the timing (distributor rotating) and idle mixture screws. But now, its really messed up (opps!). We tried a billion things by ear, because I had no timing light on me at the time/place, and we couldnt quite get it right. It would sometimes cough out of the carb, which happened over a dozen times (how bad is this?).

Also, I don't think I touched anything besides the distributor and idle mixture screw. No othe problems, ran the car between tune-ups (or mess-ups). However, on the way home, after about my tenth *tune-up*, my brakes were VERY messed up. It wasn't like they had no pressure, instead the brakes were VERY hard/stiff. I have power 4caliper disk brakes, so it was like when my car is off, and I have no *power* brakes and use the brakes. It's like the booster isn't working, very strange. I checked the line to carb, wasnt clogged, and it's not loosing any fluid. However, my fluid is very brown colored, like chocolate milk (needs to be changed?)

So few things before the build sheet:

Holley 750 carb, I ran no air filter today (the bolt holding filter on carb broke off from heat, and bad threads. So lately I've been using a wire wraped under the carb, through the gap in the manifold through two holes in the airfilter base, and tying the airfilter down (works great, but heat weakens wire fast, so I was changing it often) I need to get that bolt out of the carb, how do I? The top snapped off, and I can't get grip on whats remaining to unscrew it out...

You know the vacumm nozel coming off the MSD distributor thats suppsed to go to the carb? That's not hooked up to anything, my mechanic said my engine didnt make enough vacumm to matter or something... But the vacumm thing isnt plugged up by anything either.. its just sitting there?

Should I get my car dyno tuned? There's a local dyno place called RPM in Rohernet Park , but a pro dyno tune is $375 - ouch?!?. Also, will they fix my brake problem, or should that get fixed before or after?

Also, me fooling around earlier with the timing and idle, and my car obviously hating it (whining when i turned it off, kinda like back spinning, or something, and sometimes something shooting straight out of carb (only when I turned it off). Was that *okay* of me, I mean this engine is tough, but was I really messing it up? Is there something I should now clean, or take care of? Change oil?

Alos, an additional question. Read the stats on my engine, but currently I'm running 20W50 Valvoline (white bottle) in my 7-8 quart engine (big pan). I've been reading about that synthetic stuff, should I switch over. I'd call my engine high performance, but am I safe running this 20W50 valvoline? What do you all recommend?

Thanks so much guys!

Engine Type: 351 Windsor
Bore: 4.030"
Stroke: 3.500"
2 bolt Main Block
Connecting Rods: 5140 Forged Steel
Rod Bolts: 3/8" ARP wave locs (sp?)
Rod Bearings: Clevite77 (sp/)
Rod Journal Size: .010" under
Rod Journal Clearance: .0015"
Rod Side Clearance: .014"-.016"
Crankshaft: Factory
Crank Journal Size: .010" under
Crank Journal clearance: .0025"
Crankshaft run-out: .000"
Crank End-Play: .004"
Bore taper: .000"
Deck Surfaced: YES
Main bolts: ARP Studs
Pistons: forged Je/SRP 149606
Rings: Powerflex PlasmaMoly
Gap: .021"
Piston Skirt Clearance: .003"
Static Compression: 10.2:1
60cc Chambers
Oil Pump: Melling H-V
Oil Pump Shaft: H-D Steel
Timing Assembly: Cloyes Double
Cam Bearings: Dura Bond
Freeze Plugs: Brass
Cam: Comp Roller #432-8 ROLLER SOLID
Hydraulic Lifters: Comp 838-16
Valve Lash-Intake: .016"
Exhaust: .016"
Intake Lift: .609
Exhaust Lift: .616
Advertised Duration-Int: 279
Advertised Duration-Exh: 285
Duration @ .050-Int: 242
Duration @ .050-Exh: 248
Lobe Seperation Angle: 110
Intake Center Line: 106
Overlap: 25 @ .050" Lift
Cam Installed @ 106
Heads: Edelbrock Victor Jr.
Cumbustion Chamber Size: 60cc
Closed Chambers
Intake Valves:
Exhaust Valves:
Hard Seats: YES
Valve Guides: Bronze
Springs: Edelbrock
Diameter: 1.455"
Installed Height: 1.800
Piston to Valve Clearance-Int: .160"
Piston to Valve Clearance-Exh:
Retainers: Steel Alloy
Locks: Alloy Steel
Seals: P-C Teflon
Rocker Arms: Harland Shorr
Rocker Arm Ratio: 1.6
Push Rods: Chrome Moly
Rocker Studs: 7/16"
Guide Plates: YES
Head Gaskets: SCE
Thickness: .060"
Head Bolts: ARP
Porting: Intake Ported to 1206
Time @ 34 Total Advance

1,663 Posts
first off the oil you are running is excellent and there is no need to change,,synthetic is better but it will find and place to leak out so if you have a damp spot now you will have a leak,,

As far as timming the car with out a light to see what the initial/mechanical is there is no way to get it perfect,you shouldn't need any more than 36 degrees of total timing say at 3000RPM and if you don't have a light BUY ONE and don't buy a 19.00 one get a good one if your gonna tinker with an engine..A performance engine can be in trouble with detonation and you can't hear it,

Carb adjusting is sometimes left to the pro but here is a tip turn in the idle screws till they bottom out LIGHTLY,,then back them out a turn with a vac guage hooked to manifold vac,turn each one till you get best vac and reset idle this sometimes has to be done a couple of times,the timing will affect engine vac and may be the culprit to your brake problems

the back whinning you describe is likely too high an idle speed and or too rich idle mixture as the engine is trying to "deisel"

7,671 Posts
With a motor like that, I'd be spikeing the fuel with a little racing gas (25%).
Detonation can't always be heard in a racing motor, often damage is done before you realize anything is wrong.
ALWAYS set the timing with a strobe, don't trust your ear, 36-38 degrees is max, less if you're running pure pump gas.

(IMO) Backfiring thru the carb is probably too tight intake valve lash or fuel puddling in the intake.

2,176 Posts
It is easy to get a engine like that out of tune, I had my
car dyno tuned at they are located at Sears Point. It cost me about 200.00, including about 10 dyno runs, timing changes, jet changes. The car picked up 40 peak HP, and I thought it was running OK before I got there. You also need to buy a timing light.
I also think the backfires may have damaged your brake booster.

290 Posts
Discussion Starter · #5 ·
Sears Point isn't too far from my house, perhaps I'll take the car to The Racers Group? I checked out their website, and it looks like they just do Porches? How far in advance do I have to call to get it tuned?

So do I have to replace my booster? How do I check to see if it's blown? DO I check before or after tune?
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