Mikel Becks Heads

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BJR Racing

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Mikel asked me to post about what I had found and what I did to fix them. Well when I opend the boxes and took a good look at the heads I had noticed that they had been worked on before. I had to chuckle as the company that originally did them was a company here in Atlanta, Ga. Now they did some nice work and I know the guys that did them and know the owners of the company personally. But since they left them and went to someone else they had been changed drastically. And by this someone took a very good set of heads and almost destroyed them.

It looked like someone had tried to port on there first set of heads and went crazy on them. I noticed that someone else had installed seats on the intake side of 2 of the intake runners as they had to in order to save the heads and make them useable. Also to they sunk the seats in most all ports for some unknown reason. And because of this the valve stem heights were all over the place, the highest to the lowest was over .125 different. The ports that whoever did were cc'd at 168 cc's and the other 6 ports were 158 cc's. Then I flowed them and this is what they flowed.

158 cc port

.100......76
.200.....117
.300.....181
.400.....218
.500.....242
.600.....241

then the 168 cc port

.100......76
.200.....125
.300.....195
.400.....229
.500.....246
.600.....248

Now I had to try and get the ports to be more uniform and flow more alike so this is what I did, I cut the bowls with a 75* cutter and back cut the valves as they were the stock tulip type, and I lowered the floor a bit and this is what they flowed.

.100......81
.200.....136
.300.....194
.400.....224
.500.....239
.600.....229

At this point I had them much closer than they were when I recieved them. So now it was time to get all that I could out of them and had to get it at .450 lift as the cam that Mikel is using is olny a bit over .500 lift. So now the challenge was on. After doing more work on the ports and the short turn area and reflowing the heads they didn't increase much, and actually lost airflow. But because I have numerous sets of heads here, that I had other parts for I figured that I try some different valves and this is what happened on the flow bench.

.100......84
.200.....138
.300.....202
.400.....235
.450.....243
.500.....242
.600.....232

So I found something and then tried to backcut the valve and see what happens, and this is what it did.

.100......82
.200.....134
.300.....201
.400.....231
.450.....235
.500.....238
.600.....235

Well this didn't work so back to a valve that isn't back cut. In the meantime the new valves came in and I had a chance to do a lite polish on the bowl area and this is what they ended up at.

.100......82
.200.....164
.300.....209
.400.....242
.450.....249
.500.....246
.600.....241

I didn't just put my efforts on the intake side only, I also did the exh. and this is what they flowed on the exh. when I recieved them with a 1.60 valve.

.100......70
.200.....103
.300.....129
.400.....145
.500.....154
.600.....151

Then I cut the bowls and backcut the valves and this is what they did.

.100......74
.200.....114
.300.....138
.400.....154
.500.....153
.600.....155

Then I hand blended them and this is what they flowed.

.100......74
.200.....114
.300.....144
.400.....192
.500.....202
.600.....202

But now before I could get any further I had to install seats in 6 of the 8 exh. ports as the seats were so bad that this was part of the reason that the valve stem heights were all over the place. Then I did as on the intake side a lite hand polish and this is what they flowed.

.100......74
.200.....113
.300.....142
.400.....192
.450.....198
.500.....204
.600.....210

So now that they were getting closer to being finished I rechecked the valve stem heights with the new valves and they were almost all the same. But the 2 intake seats that were installed by someone else were set too deep and were a bit taller, but because of the thick margin valves they came out fairly close to the others.
So basically after all the repairs and installlation of some heli-coils and seats and springs the heads will live to fight another few years.
Mikel should have them on wednesday of this week (5/14/08), what he will notice will be a faster rev and a healthier sound. At the track he should see a better MPH and a good bit better ET. But this is car and chassis dependant. I hope this is what he wanted me to say about his heads.
 
Thanks for that, Bobby. I'm looking forward to getting these back and on the motor... then getting out to the track to see how much of a difference it makes.
 
Keep us updated! Great job BJR, those exhaust numbers are great! I would imagine you could run a single pattern cam with those exaust flow numbers.
 
And you didn't mention any cutting of the guides inside the bowl. (Is that the right term/part I'm thinking of? Where the valve comes out?) Did ya hit on that?
Did you hog out the bowls wider?

Tanx Bobby.
 
Rumble,
I left the guide boss alone as it really only makes the hi lift flows better and from previously ported heads it showed a flow loss below .400 lift as the port would be too large, and with a cam that only has .500 lift it was very important to keep the port as small as possiable so velocity would stay as high as it could. With cams in the .550 lift and less range port velocity is king, a port really doesn't come into effect until after .550 lift. The bowl and the valve job is most important under .500 lift, and you want to have peak flow at least .050 before max lift and realisticly .075-.100 as you have to pass this point twice in the valve motion and your only at peak for a short time. This is where small cams with lots of duration work best, because your holding the valve in the peak flow for along time.
 
Ahh, guide boss. (Damn brain farts)
Thanks.
 
BJR - Awesome! I love reading about your mods and results.

I keep plugging in your numbers into Comp Cams. I saved those heads as "BRJ Racing_mikelbeck_x-heads_fixed". I keep dreaming of having a set of massaged heads on my 340 instead of the stock X-heads. Those look to be great daily driver heads!

Keep up the good work.

Mikelbeck - looking forward to hearing how they workout in your ride.

Doug
 
socal_65dartgt said:
BJR - Awesome! I love reading about your mods and results.

I keep plugging in your numbers into Comp Cams. I saved those heads as "BRJ Racing_mikelbeck_x-heads_fixed". I keep dreaming of having a set of massaged heads on my 340 instead of the stock X-heads. Those look to be great daily driver heads!

Keep up the good work.

Mikelbeck - looking forward to hearing how they workout in your ride.

Doug
Click to expand...

I'm looking forward to it, too... they'll be here tomorrow, if all goes as planned the car will be running by Friday. Hopefully I can get to E-Town sunday to make a few passes.
 
Mikel,
I do have to say that what ever you have for jets in the carb you will need to go up at least 6-8 sizes for starters, in a holley if this is what you have. The heads will require this much more just to get even for the air flow.
 
BJR Racing said:
Mikel,
I do have to say that what ever you have for jets in the carb you will need to go up at least 6-8 sizes for starters, in a holley if this is what you have. The heads will require this much more just to get even for the air flow.
Click to expand...

I've got a Holley 750HP, it has 73's all around. So I should start with 79's or 81's?
 
BJR Racing -
Good job Bobby, those don't even look like the same heads! As an engineer I can appreciate your attention to detail. You do some awesome work. :cheers:
 
mikelbeck said:
I've got a Holley 750HP, it has 73's all around. So I should start with 79's or 81's?
Click to expand...

You may end up with something like 83 and 85 but you'll have to look at the heat marks on the plugs after you make a pass or two. When the fuel curve is correct the plug threads will have the first two threads from the chamber, will be dry and then they will look wet on the rest of the threads. At this point you'll need to look at the 60' times. Another way that you can tune is keep adding jet until the 60' times slow, then go back to what gave you the best 60'. You'll have to keep a log as you may change the jets 6 -8 times before you get it right. Do you have adjustable air bleeds in the HP carb? If so you'll need a air bleed kit to really fine tune the engine and there may be a additional few tenths. From what I've found the air bleeds that we run are, idle circuit 72-78 drill and 30-32 on the power circuit. The idle circuit is the outer most 4 bleeds and the power is the inner most 4 bleeds.

What this is going to do is lean the engine down but with the large jet it will make up the difference. Also too the engine can't get anymore fuel to it than what the jet will allow to pass through, so a larger jet will allow more fuel to the engine and will make more power. After you get a good base line then moveing the air bleeds up or down a couple of drill sizes will be seen in the ET's for better or worse, but work one side at a time. Like adjust the idle side first and then the power side. You want to run the air bleed that gives you the best ET and MPH, as you may have a air bleed that gives you the same ET but the MPH may be off. This will be where the engine is happiest.
 
It's alive!

Aside from a couple of minor coolant leaks (thermostat housing, temp sensor)
there's no issues. Sounds a lot stronger than it did... it's raining today
so I couldn't take it out for a ride, but I will later on in the week.

W00t!

:cheers:
 
LOL, I know the feeling. Diging for money for next weekend now.
 
rumblefish360 said:
LOL, I know the feeling. Diging for money for next weekend now.
Click to expand...

LOL. Next weekend is a regular race day, you could race in Street. I think Saturday is a "second chance" for All Out.
 
I'll join street if I can get there. I need a rule book and some fuel line from pump to carb. I'll get teched and thrown out.
 
Im going to get my heads done by bobby also, so I want to know how the car runs. And I hope it runs really well, so good luck.
 
So do I. ;-)

As long as it's not raining tomorrow night I'm gonna pull it out of the garage. Before I do that I'll set up the video camera to get some video & sound of it.
 
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