Installed BLP Blocks on 4150 HP - Won't Idle, Super Rich

[CDN]

Ok that bsd then thats an internal fuel leak issue as said not a tuning issue

[Dohctor_32V]

I believe I found the issue! The power valve plug was suspect but not the cause. I just drilled some .031" IFR jets, went to install them and noticed the IFR jets I received from BLP with the blocks were too long and sitting nearly flush with the gasket surface when installed. I believe the IFR jets are being blocked off for the most part. I can't believe I overlooked that upon assembly. I have not talked to BLP yet. I take it they are closed on Fridays. I can't test the theory because out of all the blanks and jets I have, I do not have these in 1/8" length and I don't want to whittle any down to that length. Not today at least, LOL

I would assume those jets should have been 1/8" long. Can anyone with experience with the BLP 5 hole, adjustable, 4150, gas blocks confirm this or advise how deep these should sit below the gasket surface?

Also, I may go with standard PV gaskets instead of O-rings unless there is an issue with it. Seems they will seal just fine to me. Your thoughts / experience would be appreciated on that as well.

Thanks

[CDN]

I just checked my box yes they are 1/8” blanks screwed they go a bit below flush if I recall never thought about the length but you pbly right to long will create an issue
My BLP block dont have O ring on pv but they older
Your original tune should be fine although the TSR might be a bit big

[Dohctor_32V]

Thanks.

The transfer slots measure .024" (exactly) x .300" (best I can tell on the length without removing the throttle plate).
I'll have to see how the TSRs react. I don't want any more variables at this point.

I am going to wait until I can talk to BLP before moving ahead. The IFR jets I received measure .180" long. I believe either the jets are too long, or blocks are not threaded deep enough.

[jmarkaudio]

If you cover an idle bleed and it picks up RPM it's lean. I use 1/8" long set screws. IFR should be between .035-.037 usually.

[Dohctor_32V]

Thanks for the replies. I got the correct IFR jets from BLP. They had sent the wrong length and I failed to catch the issue upon installation. The car is running fine, but I still have some fine tuning to do when it is not cold and raining.

I know the following process description seems disorganized, but we were doing all of this late after work, short on time and not in a shop setting. The main focus was to get the carb functioning well enough to run on it's own.

I believe I will need to back off on the LSAB since the mixture screws seem to be happy around 2 turns out. I used .072" LSAB with .033" IFR this time. Previously I had .031" IFR with .069" LSAB and mixtures screws were happy at 1.75 turns out. This was with different metering blocks. I plan to drop back to the .069" bleeds with the .033" IFR. On second thought, I think cruise AFR should be checked first.

As it stands, the engine has new R44XL plugs, and initial timing is 26 degrees BTDC with no hard starts and no pinging. I assume this will change when the weather warms up. Probably should have backed this down 4 to 6 degrees because the centrifugal advance contribution was unknown due to not having light springs to test it with. The owner of the car had two vacuum gauges - neither of them worked when I got to his garage, and I did not take my gauge because he had two. So, no vacuum readings yet. It seems pretty low just by "feel", so I am guessing this engine has some healthy valve overlap.

We are planning to go through the distributor and make sure everything is in good shape and possibly test some advance springs with the stock weights or weights from some other HEI distributors laying around. Then do some tuning with those and the adjustable vacuum canister. The advance seemed to be hanging just a little, so there may be some lube or wear issues there.

I plan to have a good vacuum gauge and wideband on the next go around.

Please feel free to offer advice on anything you would approach differently or correct any misunderstandings I may have.

How much initial advance do you folks recommend as a starting point with an engine such as this?

[rgalajda]

4 corner idle mixture screws should be 3/4 turn out approximate. Not 1 1/2 to 2 turns.
2 corner idle mixture screws should be 1 1/2 turn out approximate

You need to get idle fuel, vacuum , idle timing sorted out first before looking at cruise AFR.
First get a vacuum reading at idle speed, taking note of rpm, and since it is a 4speed take another reading with clutch slightly out to simulate putting an automatic in gear, leaving timing as is.
You can report your findings.

Here is the setup I would start with, and adjust from there.
Primary jet 70 Sec 80
Pink cams on #1 position
32 & 35 squirters OK
IFR .035 both, front and back
6.5 power valve
PVCR .060

IAB .070
MAB .028 is OK

You can leave the TSR at .082, but I would say this is going much smaller once you see the cruise AFR such as .068 on primary if the secondaries are still closed at cruise speed.

Adjust primary slot exposure between .020 to .040
Secondary closed as long as it doesn’t bind , like 1/4 turn on set screw.
Initial timing is going to depend on vacuum at idle.
Why were BLP metering blocks installed?

[Dohctor_32V]

BLP blocks were installed because the original, non adjustable HP blocks were modified by "Stealth" with the following:


PVCR - .068" in primary and secondary metering block.
Emulsion Feed Air Bleed (3 per channel) - .032" in primary and secondary metering block.
Cross Channel "kill" Bleed - .034" (upper-most hole above the three emulsion feeds) in primary and secondary metering block.
Primary Idle Feed Restrictor - .037" upper, with a .028" lower restriction.
Secondary Idle Feed Restrictor - .037" upper, with no lower restriction.

[CDN]

Sounds like you have it pretty close glad the 1/8” plugs were right
I do agree 4 corner idle sb 3/4-1 1 1/4 max when idle circuit is right
Id be inclined to go back to .033 ifr with .070 iabs
Dont recall if throttle blades drilled for idle air hopefully not
If not and low idle vacuum you may have to crack sec open a bit to het 1050’s idle speed hot
BBC big cam low idle vacuum ( below 10hg ) and the factory heads like lots of initial id say 16-18 with 20 centrifugal for 38 yotal plus about a 12* vacuum can

[Dohctor_32V]

The throttle plates are not drilled. I avoided that in hopes of dealing with idle speed through initial timing, vacuum canister and front / rear blade adjustments.