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 Post subject: lack of performance
PostPosted: Mon Apr 19, 2021 9:22 pm 
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Joined: Fri Jul 08, 2016 2:19 pm
Posts: 81
Location: Odessa FL, Blairsville GA
I have posted quite a bit about this 64 Galaxie with a 400 block , Boss 351 heads, solid roller, Torker, Eagle rods, Jamar stud girdle, NASCAR 830 carb, 4.11, 4 speed.

I have the engine pretty much straightened out, but it never has, and still doesn't make the power it should, even though I just added Hooker 1 3/4 headers.

It was a circle track motor that was supposed to make 600hp back in the day., which seems realistic, based on the parts. Compression checks out at 180, timing is set right, the carb started with 110 jets square, and the builder put in 90's for me. I since went to 88's, and it hasn't been bogging.

We are trying to figure out what is going on. I am getting a Holley 750 rebuilt to see if that helps. There is also a chance that the cam was retarded, which circle track guys did to reduce the wheel spin coming out of the corners, but it is still not making big power up in the 6000 rpm area.

Someone also stated that maybe the triple springs on the engine are too heavy, not allowing the mill to rev quickly?

The last possibility is the Unilite distributor. The vacuum is blocks, as the NASCAR carb has no vacuum port. I have very light springs on it, advance is all in by 2500, and everything seems to be right.

Any thoughts on the likely problem(s) are appreciated. I thought the headers would do the trick.
Thanks.


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 Post subject: Re: lack of performance
PostPosted: Tue Apr 20, 2021 6:21 am 
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Joined: Mon Oct 29, 2012 9:05 am
Posts: 2891
Maybe it wasn't 600 hp?

Valve springs for sure isn't the issue. I use 1200 lb valve springs on some engines that turn 8500-9000 rpm.

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 Post subject: Re: lack of performance
PostPosted: Tue Apr 20, 2021 7:08 am 
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Joined: Fri Jul 08, 2016 2:19 pm
Posts: 81
Location: Odessa FL, Blairsville GA
Yes, that is possible. This info didn't come from the seller, though, came from a credible source with knowledge of the motor who even pulled the pan to confirm it has Eagle rods, was deburred, etc.

With the parts I have listed, that are verified, doesn't it seem like it should be making plenty of power?


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 Post subject: Re: lack of performance
PostPosted: Tue Apr 20, 2021 7:30 am 
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Joined: Mon Oct 29, 2012 2:49 pm
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Location: Orange County, NC
How much compression was it supposed to have? 180 psi seems low to me for something that came out of a racecar. That makes me wonder if the cam is retarded. The few times I've put a cam in retarded all it has done is made a lazy pig out of it.


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 Post subject: Re: lack of performance
PostPosted: Tue Apr 20, 2021 7:31 am 
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Joined: Mon Oct 29, 2012 9:05 am
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Not necessarily.

Who knows what the heads flow and the cam can be anything. Just because it's a solid roller doesn't mean it will run like a mashed cat.

From the 60's-70's, one thing I have learned is that guys put WAY TOO BIG of cams in stuff. If the heads don't work well, then you have an extremely narrow band where it will make power......IF it makes power.

Another thing to think about is that you have put a supposed circle track engine in a big heavy pig of a car.

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 Post subject: Re: lack of performance
PostPosted: Tue Apr 20, 2021 7:42 am 
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Joined: Tue Nov 06, 2012 12:02 pm
Posts: 494
Without knowing the actual specs, you can't really have expectations on how it will perform.

Buying a used motor, I would have torn it completely down and verified everything. It's nearly impossible to determine compression ratio from a cranking compression test. But I know our circle track sbc's had 200+ on the good cylinders, and that was on a well worn engines with plenty of laps on em. Truthfully, with 12:1 and a super late intake close point, it might only get 180, only running the numbers would give you the actual truth.


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 Post subject: Re: lack of performance
PostPosted: Tue Apr 20, 2021 8:49 am 
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Location: Orange County, NC
I was just speaking based off my experience. And that is, I've never had a 12-1 drag race motor EVER be less than 200 if the cam was even remotely close to being installed on the correct centerline. Most of them, even with a much larger cam than any circle track motor would use, were up around 220 psi. Even one of my 10-1 street motors was over 190 with a solid flat tappet. My 402 inch, 15-1 clevor with a "too small" roller cam would bury the needle on a compression tester.


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 Post subject: Re: lack of performance
PostPosted: Tue Apr 20, 2021 3:49 pm 
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Joined: Mon Oct 29, 2012 2:39 pm
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IIRC, the 10.5:1 351C in the Falcon runs around 150~160 cranking. It's not very high. I think the 393C was around 180 with a Brent cam, 11.5:1 static.

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 Post subject: Re: lack of performance
PostPosted: Wed Apr 21, 2021 12:48 pm 
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Posts: 494
Speaking of all this, I watch youtube while eating lunch. Being a gearhead most of it is car programs, how it's made, and racing stuff. Today I watched a show on engine power/powernation that was titled "How Camshaft Timing Affects Engine Performance - Engine Power S8, E7" https://www.youtube.com/watch?v=wimUgFd0Qkg

They built a 350 sbc into a 383 stroker with an alloy top end, solid roller 110 lsa 236/242 @ .050 cam. About halfway through the episode, they checked cranking compression, and got 170 psi with the cam on a 110 ICL. They then advanced the cam to ICL 100 degrees, and the rechecked cranking compression was 205. I don't recall the compression ratio, but I thought it was a neat test showing how much cranking compression is gained by 10 degrees of IVC change.


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 Post subject: Re: lack of performance
PostPosted: Wed Apr 21, 2021 6:17 pm 
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Joined: Fri Jul 08, 2016 2:19 pm
Posts: 81
Location: Odessa FL, Blairsville GA
Thanks for all of the good input.
This Galaxie only weighs about 3700 lbs. That surprised me, until a buddy reminded me that air doesn't weigh anything. There's a ton of open space in there (trunk, cabin).

The thought of a retarded cam is certainly a possibility, as some circle track cars were set up that way to reduce spin coming out of the corners. But, wouldn't a retarded cam just move the power band up and have a strong top end? Mine doesn't up to 6500.

We are going to check for timing chain stretch, but not sure if that would kill performance.

We are also rebuilding my old 750 VC Holley, which I replaced with an Ernie Elliott tuned 830 Winston Cup carb that they put 90 jets square in. I since went down to 88's. The carb does not bog or smoke, so it may not be too far off.

The Unilite distributor has light advance springs, all in by 2500. We have tried 10 degrees initial through 17 btdc. The spark is orange with some blue. Still no great difference. Is there something else with the distributor that could be causing this problem?


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