Issues with C4 and new Blueprint 306

[Torkman66]

Can’t recall, but what stall does his TC have?

 

[brewchief]

Simple question, are you getting full opening of the carb? Is full throttle opening the butterflies 100%?

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[deltabronco]

Simple question, are you getting full opening of the carb? Is full throttle opening the butterflies 100%?

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Yes, it’s fully opening

 

[deltabronco]

The OP hasn't shared many engine specs, but based on the numbers in post #21, the cam was almost certainly selected to take advantage of their aluminum heads. That's way more lift than most iron heads can use. I had an Explorer 5.0 for years with gt-40p heads and a cam with similar specs. It made good power but not until about 2500 rpm. Then it made plenty. A street cam, but not an RV cam, though with the (likely) aluminum heads, even if it isn't a stump puller it should go like crazy in the mid range.

And I agree m_m70's carb comments. It might be right, but probably not. And what about the distributor? What kind? What's the initial timing set at, and how much total advance are you getting?

I did confirm it’s a street cam. The distributor is a

PerTronix Flame-Thrower Plug and Play Billet Distributors with Ignitor II® Module D130710​

Initial timing is set at 10 degrees with total around 32. Engine seems to be runnning fine. I drove it about 30 miles today and response seems better but it still sluggish and underpowered. Also area around bell housing seems a lot noisier than it did before. I realize that going from 3:50 gears to 4:10 would make the rpm’s increase at a lower speed but I would also expect a good increase in torque, which really doesn’t seem to be the case. I’m gonna call the mechanic on Monday. Something definitely isn’t right.

​

 

[bronco italiano]

Where do you live? See if one of the board-guys lives near you. These guys are as good as they get.
What is your vacuum reading at idle?

 

[deltabronco]

North of Raleigh in Wake Forest. Yeah, I’d love to meet up with someone.

 

[deltabronco]

Where do you live? See if one of the board-guys lives near you. These guys are as good as they get.
What is your vacuum reading at idle?

9-10 psi at around 600 rpm

 

[bronco italiano]

Bring the idle up to 900 rpm (when warm) and get a reading in mmhg

 

[lars]

Bring the idle up to 900 rpm (when warm) and get a reading in mmhg

Or inches, lol..

 

[deltabronco]

Or inches, lol..

No worries. I would’ve just multiplied it by 51.7149.

 

[m_m70]

Bring the idle up to 900 rpm (when warm) and get a reading in mmhg

I agree with this but I would keep it at 600, hook up the vac gauge, bump timing up to 14*, see what the vacuum is then, adjust idle to 900rpms and see if that increases vacuum even more. 9 inches vacuum is low.

 

[deltabronco]

So based on the limited info I posted here, are we thinking the performance issue is in the engine/ carb tuning and not in the transmission?

 

[deltabronco]

Also another thing I need to mention is that the engine sounds like it’s screaming at 2500 rpm (50 mph). I knew the 4:10 gears would be lower but this seems a bit extreme.

 

[m_m70]

Also another thing I need to mention is that the engine sounds like it’s screaming at 2500 rpm (50 mph). I knew the 4:10 gears would be lower but this seems a bit extreme.

So I assume you have a tach and know you're at 2500 rpms?? What size tires you running??

 

[deltabronco]

Yes I have a tach. I’m running 32x10.5 r15. I had 3.5 gears on the rear end and changed them to 4:10 at the recommendation of the transmission mechanic.

 

[m_m70]

Got everything back from mechanic today. Pump was shot so they fixed that and there was an issue with the transfer case so they got replaced

So does the transmission make any bad noises?? Like back in August (original post) or did the new pump fix that?
Curious what the issue was with the transfer case to where they had to replace it but lets just stay with the transmission for now.

Test drove it and response was sluggish and under powered. Same response as if choke was engaged. I’m going to change out gas and check timing.

Did your mechanic test drive it after he installed the transmission and new transfer case??

The transmission mechanic replaced the TC.

Was the new TC from Kurt bad??

Unsure about the wide band on the exhaust.

That would be for a O2 gauge to measure your air fuel ratio to adjust your carb or for a computer to adjust afr for efi. Pretty sure you don't have a gauge so don't worry about that.

Also area around bell housing seems a lot noisier than it did before.

Really helpful if you could describe the noise.

Also another thing I need to mention is that the engine sounds like it’s screaming at 2500 rpm (50 mph).

Are you getting three solid shifts out of your trans??
4:10 gears with 32's should have you around 2250 rpm's at 50mph (that's with an added 100 rpms for auto trans). see here for calculation. https://purperformance.com/p-29669-rpm-calculator.html

So based on the limited info I posted here, are we thinking the performance issue is in the engine/ carb tuning and not in the transmission?

I'm going to say both are probably having issues.
Motor - 9in vacuum is too low. Check for leaks, make suggested adjustments and see if you can't get that number up to at least 15.
Transmission - RPM's seem high and not sure what noise your transmission is still making. Take it back to the mechanic who did the install and see if he can diagnose.

On another note, take your front driveshaft out until you get your front differential gears matched to back. Better safe than sorry.

 

[deltabronco]

The picking noise coming from bellhousing ( ticking noise). Transfer case kept slipping back in neutral and evidently there was an install issue to the transmission. Mechanic drove it but said the engine ran really cold, I’m guessing that what he thought was the cause for lack of performance ( temp gauge reads about 120 but I put a temp gun on the radiator and thermostat housing and was getting 170. Guess the temp sensor is off) the pump broke when I installed last time. I guess that sends metal into the TC and they replace as a result. It is shift 3 times. Has been shift better since I’ve been driving. I’ll definitely take front drive shift out.

 

[m_m70]

The picking noise coming from bellhousing ( ticking noise).

How loud is the clicking noise? Are you 100% positive it's coming from the transmission? Use a stethoscope type device to pinpoint the clicking noise. Wooden dowel works just as well. I'll bet that it's not the transmission, it could very well be an exhaust leak. Hoping not a lifter tick with a new motor.

On the motor side, get your vacuum gauge and timing light out and see if you can't get those numbers bumped up (advance timing should raise your vacuum). Test drive it and see if it improves at all.

Also, have you checked that your choke is opening and not stuck or hung up on something?? Wouldn't be the first I've seen that happen for sure.

Finally, where is your temp sensor mounted? Have you checked your gauge (ground out wire and gauge should peg out). Also, if you use thread sealant, don't use Teflon tape. It'll mess with the grounding. Use a liquid sealer if you need to.

 

[bamabaja]

I feel ur pain. Just pulled a BP 306 with less than 50 miles with broken ring on #1 cylinder. in ur efforts to run down ur gremlins I didn’t see a compression test. Oh, did u know BP has stopped making the engine ? Just saying.

 

[deltabronco]

I feel ur pain. Just pulled a BP 306 with less than 50 miles with broken ring on #1 cylinder. in ur efforts to run down ur gremlins I didn’t see a compression test. Oh, did u know BP has stopped making the engine ? Just saying.

Well, that’s great. I’m taking back to the mechanic on Monday. May get it running then sell. Hate to do it, but I don’t have the know how to work on it. Evidently no one in my area does either.