Can Anyone P/P My Cyl. Head?

[Username]

Does anyone here know of a respectable person or shop that ca do a good joc of port and polishing my 5MGE head in or near the Tampa,Florida area? Id do it but I dont want to f up and i cant start practicing on my spare cyl. heads for a while. Thanks.

[Username]

i guess not

[BuddyJ]

Call BYP in Miami. They'd know. www.back-yard-productions.com

[Username]

too far away but thanks anyways

[Junkie]

I have to add a comment here.


If you do have a head p+p,make sure it is done by a reputable shop,that actualy has a flow bench,and is VERY knowlegable.MOST people that claim to have done a p+p have not flowed before or after.Also,unless done correctly,more often tha not,you will actualy hurt the performance and flow characteristics.A mild port match,is all I would ever do to anything that was not going to be a full on track car.Have seen too many cars lose performance,because the guy doing the work,really had NO isea what he was doing.Bigger/smoother is NOT always better.Even met a guy at the drags,that kinda knew what he was doing,F up a set of buick stage 4 heads.Car lost 1/2 second.....to look at the heads,the work was beautiful.

The casting roughness is left on most heads for a reason.......it helps fuel atomization.Smooth walls can actualy cause the fuel to "puddle",not vaporize.On injected cars,this problem is usualy not as severe,as on carbed engines,but it can/does still happen.

[williamb82]

if you dont mind having it done with no flow test numbers and dont need it done right away, send me a pm. ill get you hooked up. dave does great work imho, but it takes awhile as he does it in his spare time. i beleive he is done with the actual port work on my 7m head, so i can ask if he is willing to port a head for you(he may or may not. depends how his schedule is). the port work he did for me is awesome. he is a very patient and detailed person. my head isnt finished, but thats only cause i have more hardware to buy for it before i can get the valve seats cut for the oversized valves.

[Dangerous Ken]

Flowbench is really a necessity as Junkie stated.
The other option is extrudehoning at ~$800...

Ken

[Username]

the only problem is all the shops around here probably dont even know what a flow bench is so im just going to look for more shops in the tampa area. Thanks for the info guys. William how long would it take for dave to p\p my head and how much would it cost if he could fit it into his schedule?

[sarinas_dragons]

I was wondering what your budget for p&p? The reason I ask is because when I computer model the head's flow it hardly seems to need it. It flows very well considering the choke point, which is unchangable.

One option is to look at the ports and compare the relative condition of one to the other. By looking closely you may see casting differences port-to-port. Making sure to avoid danger areas is number one. Number two is port match gasket-manifold. Number three is remove casting irregularities and excesses. I think you could do it.

Yamaha was way ahead of many in terms of swirl or squish. Current technology says the intake charge is doing four laps around the cylinder. I don't think there are many things that can be done to our heads that aren't a compromise. I haven't seen any dyno comparisons to back up any p&p head claims, can someone add to this?

5MGEs are seriously undercammed. That is the main problem, not port flow. A rough guideline for all-out racing is intake valve lift can approach .37 the valve's diameter which would equal a lift of .640! All the cams for, say a Toyota 20r, have lifts that high for that level of performance. In this respect our valve springs enter coil bind just before .700. So it's not the head, it's not the valve size, it's not really the springs even though they need higher seat force for higher lift and higher rpm. It is the relation between the cam and rocker that needs to be explored.

In the thread TRD cams:

http://www.celicasupra.com/vbforums/showthread.php?t=1292&highlight=trd+cams

Dave A. has developed this thought. I believe even more needs to be understood about the dynamics of the rocker arm design. We are almost there in terms of understanding. But the rockers are the missing link. Get rid of this worry and we can run some cams and start making some power.

[CarFreek]

:stupid: My 6m has a P&P done by Helmsman(Bill) from here-He did a great job-took his time port matching and and cleaning up-however, unlike some other engines, the gain you get isnt as large-I believe the dyno difference was around 5-7 hp-Cant verify this because I think he did some other flow work(RC T/B, Intake pipe, AFM) between his baseline and final dynos-We need more CAM-

[stevrock]

I have to add a comment here.


If you do have a head p+p,make sure it is done by a reputable shop,that actualy has a flow bench,and is VERY knowlegable.MOST people that claim to have done a p+p have not flowed before or after.Also,unless done correctly,more often tha not,you will actualy hurt the performance and flow characteristics.A mild port match,is all I would ever do to anything that was not going to be a full on track car.Have seen too many cars lose performance,because the guy doing the work,really had NO isea what he was doing.Bigger/smoother is NOT always better.Even met a guy at the drags,that kinda knew what he was doing,F up a set of buick stage 4 heads.Car lost 1/2 second.....to look at the heads,the work was beautiful.

The casting roughness is left on most heads for a reason.......it helps fuel atomization.Smooth walls can actualy cause the fuel to "puddle",not vaporize.On injected cars,this problem is usualy not as severe,as on carbed engines,but it can/does still happen.

Yeah, alot of it has to do with the way the air is pressurized.

I've explained intakes like this before.

It's very similar in make-up to the septic system in your house. If you go too big, it will be ineffective, if you go to small, it'll back up.
If it is too big what will happen is the drainage would mosey along at a liesurly stroll, not maiking a quick exit.
But, since they are usually either 3 or 4 inches in diameter they are small enough so that the "junk" keeps it's momentum making a quick exit to the other end.
If it were smaller, it would lose it's momentum and not flow very fast.

Get my point? Go to big, sure, it's capable of getting more air through it, but it won't be able to have that type of pressure that you want.
Probably what happened to buddy's Buick heads, did too much work to them, but I'm sure they did look pretty.

[Dave A.]

Yeah, alot of it has to do with the way the air is pressurized.

I've explained intakes like this before.

It's very similar in make-up to the septic system in your house. If you go too big, it will be ineffective, if you go to small, it'll back up.
If it is too big what will happen is the drainage would mosey along at a liesurly stroll, not maiking a quick exit.
But, since they are usually either 3 or 4 inches in diameter they are small enough so that the "junk" keeps it's momentum making a quick exit to the other end.
If it were smaller, it would lose it's momentum and not flow very fast.

Get my point? Go to big, sure, it's capable of getting more air through it, but it won't be able to have that type of pressure that you want.
Probably what happened to buddy's Buick heads, did too much work to them, but I'm sure they did look pretty.




Funny you should mention pipe sizing in relation to flow characteristics. You would love how the potable water supply to the building that I live in has been reworked. The sewer piping is OK, but the potable water supply is a real work of art. The folks that live in the condos still bitch and whine about the fluctuation in water pressure and have been doing so for approx. 15 years now, yet the manager still to this day refuses to see my point that you can't adequately supply 20 occupied residential condos with a single water supply line that is only 1" in diameter. Yes........ 20 occupied condos, each with 2 full baths, kitchen sink, clothes washer, dishwasher, and a 40 gal. hot water heater. All 20 condos being supplied potable water through a single 1" flowmeter and 1" plastic PVC pipe. Go figure! The pressure at the water main is 100 psi and you should see the tiny flowmeter scream for mercy when the water demand is high. Now I've heard of such terms as "max. flow velocity", but this is just plain ridiculously stupid. Maybe the flowmeter will seize up soon and my water bill won't be as high. :facesjump Maybe I should present this question to the manager; "So, how's that water driven turbo holding up that you asked me about"? :)

[Username]

well if its only minimal gains then i might just not worry about it right at this moment. I need to get this engine together anyway. I need a better car. Since i have 2 spare 5MGE's in my garage and a spare cyl. head i think what im going to do is do the p\p to one of the spare heads and put it on a flow bench before i start then port it a little and take measurements the flow bench it again, and keep doing that it flows the most air at the greatest velocity. What do ya guys think?

[williamb82]

talk to wes. he ported and polished a 5m head himself and has a very nice writup on his site and he did notice some gains in the seat of the pants meter. not sure if he dynoed before and after with just that mod.

[Username]

yea i was looking at that the other day and thats what i was planning on doing to one of my spare heads

[williamb82]

dave has posted here in this thread, so im not gonna bother emailing him about it since he has seen this. if he has time im sure he will pm you to let you know.

[Dave A.]

Sorry for my babble about undersized water pipes! :) I should've posted that in the rant thread in the General Chat section. :badger:


I appreciate the offer from several members to have me P&P their cylinder heads, but I'm afraid I'll have to pass. This is mainly due to most peeps wanting a head P&P'd a certain way for X amount of dollars. I wouldn't feel right about accepting money for cylinder head work that may or may not provide what the owner is expecting as a result of my work. The work that I've performed on the 5M and 7M head for William has still yet to be tested for flow performance and overall performance gains, but we'll keep everyone posted on the results once the heads have been completed, flow tested, and put to the real test on the dyno and the track. If we see some nice flow rates and performance gains then perhaps I may do a write-up on the P&P work that I've done for William for his particular engines. This way, he could post the results and then I could follow up with a write-up with pics. of the P&P work to show others what was done and why.

Thanks again for the offers!

[blackwidow]

if you want some good improvements for low dollars, or more bang for your buck.

If your an good with a grinder, port match the intake and exhaust ports yourself.

then send the head off to get a three angle valve job. send the valves to and get the to match with a back cut of the same degree as the chamber.

usually this doesn't cost as much, but you deffinately see gains all the way around. Most of the time a good 3 angle valve job can increase flow 25% in the first 1/4 inch of valve lift. Anyway it is something you will notice seat of the pants.


(sucking at spelling)