[SleepR DSM]

I just had my cylinder head ported. I really don't know much about porting. If you have some knowledge on the subject, can you tell me how this flow chart looks to you? The Porting was done by BJ's cylinder heads.



Before and After Flow Bench Test Results on Porting

 

[SleepR DSM]

bump

 

[SleepR DSM]

Anyone?

 

[SleepR DSM]

I know this is an old thread.. but I was hoping to find someone who could offer educated input. Are the improvements minimal, average, good? Is there something I could do to explain better what you are seeing? Although I'm no cylinder head or porting expert myself.

 

[RapedApe]

for future reference....if BJ did the head you need not ask if the work is good. it's the BEST. most backyard port jobs or Joe's Machine Shop jobs will yield maybe 10-20 cfm and will possibly even kill velocity at that small of a gain. BJ worked your head out 40 cfm on the intake side and i bet you don't have any less bottom end than before. that head is definately capable of 10s with the right cams. keep in mind that you won't see 270 cfm on the intake side with stock cams. you need web cams 546/547 or hks 272's to see lifts near .400".

 

[Rick99gsx]

what stage was the work performed on the head?

 

[RapedApe]

that would be a stage 3 when he had it done in 2001. but at that time he didn't get ss valves, springs and retainers unless he paid extra. now that would be a stage 4 and come with the 1mm oversize ss valves, crower 85 lb. springs, and groden retainers. current price for that work is $1695.95

with stage 2 work from last year (20 cfm increase at .400" on intake and 10 cfm on exhaust), stock size ss valves, bronze guides, stock springs and retainers, and web cams... i ran 11.26 @ 126 with an fp 3055 and a blown headgasket. this year BJ has just finished a stage 5 and sheetmetal for me. i couldn't be more anxious to get to the track. again, his work is unparalleled.

-Chuck Cobert

 

[Rick99gsx]

sweet, I'm waiting myself for a stage 2 for my 1g(future daily driver) and once I get that runing my 2g wi'll be getting stage 3 or 4 for the 2g (which might get stroked)

 

[TEC]

I'd be very interested to see some before and after dyno's with these heads. My guess would be that unless the car is pushing the limits on its setup, that the ported head will probably hurt performance rather than help.

I can't give a resonable quanitative explanation as to why I think this would happen, its just a gut feeling.

 

[SleepR DSM]

I'd be very interested to see some before and after dyno's with these heads. My guess would be that unless the car is pushing the limits on its setup, that the ported head will probably hurt performance rather than help.

Just as a side note, BJ has taken a DSM with a stock head, put it on the dyno, then ported the head and put it back on the dyno quite a few times. The results, what worked and what didn't work, are in part how he determined his own method for porting the heads.

Still, I agree. It would be interesting to see such a dyno comparison. Too bad the head can't be reverted back to what it was just for the sake of comparison. I did have 1mm oversize valves installed. There are stock springs and retainers.

That head helped make 276 whp at 15 psi with a stock side mount intercooler, stock cams, and running quite rich. In a couple of months I'll hit the dyno again. I am going to run as much boost as the car can handle, leaning it out a bit, with the addition of a large FMIC, Sheet metal intake, and HKS 272/272 cams or equivialent. I'm hoping for 400whp, but... we'll see.

 

[anomalyinva]

for future reference....if BJ did the head you need not ask if the work is good. it's the BEST. most backyard port jobs or Joe's Machine Shop jobs will yield maybe 10-20 cfm and will possibly even kill velocity at that small of a gain. BJ worked your head out 40 cfm on the intake side and i bet you don't have any less bottom end than before. that head is definately capable of 10s with the right cams. keep in mind that you won't see 270 cfm on the intake side with stock cams. you need web cams 546/547 or hks 272's to see lifts near .400".

The stock head is good for 10s.

 

[RapedApe]

The stock head is good for 10s.

go for it pal.

 

[TEC]

go for it pal.

No need for him to "go for it". It's already been done.

Guess you didn't know that.

 

[RapedApe]

i know that ass. i also know shep runs 8.67, curt brown runs 9.4's with no nitrous, dan cokic also in 9's without nitrous on fp 3065, dre whatever makes 503 awhp with t3/t4, leon reitman has gone 11.8 on a 14b, etc. etc.
oh, and i went 11.2 on a 2g maf, stock ignition, blown head gasket, 360 treadwear falkens, yada yada.

does this mean that you or joe schmoe is going to do any of this? not exactly. but i guess you didn't know that.

a lot of stuff can be done, but you most likely will not do it. and when most people push the limits of this or that stock part or whatever to accomplish an impressive feit...it breaks soon after. if that's your flavor, i'll let you know if i can get this stock tranny in the 9's this year. oh, and the gm maft is coming with it.

 

[TEC]

i know that ass. i also know shep runs 8.67, curt brown runs 9.4's with no nitrous, dan cokic also in 9's without nitrous on fp 3065, dre whatever makes 503 awhp with t3/t4, leon reitman has gone 11.8 on a 14b, etc. etc.
oh, and i went 11.2 on a 2g maf, stock ignition, blown head gasket, 360 treadwear falkens, yada yada.

does this mean that you or joe schmoe is going to do any of this? not exactly. but i guess you didn't know that.

a lot of stuff can be done, but you most likely will not do it. and when most people push the limits of this or that stock part or whatever to accomplish an impressive feit...it breaks soon after. if that's your flavor, i'll let you know if i can get this stock tranny in the 9's this year. oh, and the gm maft is coming with it.

Why do you feel it necessary to insult me for pointing out something to you that I thought you didn't know? You made a comment and I explained your assumptions were in correct. Right now I could easily turn around a flame you, for what you obviously do not know, but it seems your own words will make the fool of you.

Not only are there guys in the 10's with the stock head, I personally know another guy near Atlanta that has gone 10.90's on the stock head, and one here in NoVA. For the 1g head it seems there is more than enough flow there to get the job done.

Not only that, you further make a fool of yourself by guessing at what anyone has or has not done. You shouldn't be so presumptuous. Especially since you have no data to support that a ported head is necessary to run 10's on a DSM and especially when the data out seems to point in the other direction in more than a few cases. If you were only a bit smarter, and had asked around with some of the guys that's been modding these cars for a while, you would have learned that a lot of guys LOST power after porting the head instead of the opposite. Porting, as I pointed out earlier, according to the data, seems to be the absolute last thing that should be done to maximize the engines potential and even at that the person is only likely to see a small relative gain with a substaintial low end loss.

From my own personal experiences with a 2g DPR stage 4 ported head with a welded clover leaf design, a stock 1g head with 1mm over valves and 2mm over valves, a heavily ported 1g head with stock valves, and a few other combinations over the past 10 years (8 in total). I've noticed that the stock head seemed to do as well as some of my other more worked heads. Other shops that I've spoken to have seen the same.

If you got facts to back up your claims, post them, if you're going to debate someone, then debate them on the facts, don't go throwing around insults, because if you are proven wrong you only make yourself look worse.

 

[RapedApe]

i thought you were being a smartass. as i said, i know it's been done. i too have had experience with various heads. i've had light 10-20 cfm port jobs with 3-angles and 5- angles done by a 2 notable local madhine shops, a couple of self ports, a bj's stage 2, a bj's stage 3, etc. there is a lot to take into consideration. true it's one of the last things, if not the last, on the road to building a very respectable 1/4 car. but for people running turbos in the 3065, 60 trim, 60-1 arena, a ported head will help. with turbos flowing that much cfm your stock head will be a bottleneck. yeah, maybe it will get you by, but nonetheless it's a bottleneck. of course a 40cfm head job may hurt a car running a 16g on bottom end. you just have to put things together right.

bj has put so much work into his heads and intakes that he has gotten out of domestic v8 stuff that got him in the game originally. he will not sell you something that won't work well with your combination. if this guy called him and said i have this and that, and BJ recommended that stage 3...then that's the best head for his car. last year i wanted a stage 3 but for what i was doing he said stage 2. this year with nitrous, larger turbo, 75mm accufab, 3" icp, sheet metal; he said stage 5.


talk to guys who have been in the game for awhile, eh? r u serious? i've been doing this for about 4 years on and off. i put this car together one time from dec. '02 thru mar. '03. and have a total of 12 track passes in it. never before have i even drove a car down the track. and i think i'm doing just fine. so you've been doing this for 10 years...what's your best e.t., mph, dyno #?
i'm not going to start slinging my cock around here, but i do have slips and videos to show where i've been.

 

[TEC]

I'm a roadracer, not a drag racer. I'm one of the few individuals that doesn't get any thrills out of driving in a straight line for a few seconds. The last time that I went to a drag strip was in 1992, well before I ever owned a DSM. Regardless, I'm not trying to hijack this thread to discuss my own personal accomplishments or get into a pissing contest with anyone. I'm only interested in discussing the true facts regarding head porting and performance concerning the DSM.

Back to the subject at hand, as I stated earlier, I've experimented with several combinations myself and I've spoken with some other tuners (well known and not as well known) that have seemed to experience a lot of the things that I've seen regarding porting. One tuner that I know of has told me that his entire method of porting has changed due to his own personal testing. His only real porting, according to him, occurs in the throat area around the intake and exhaust valves and on the exhaust ports. Other than that, he is adding material to several areas of the head. He's reported significant gains by doing so. This seems to fly in the face of what I see from a lot of DSM companies that are porting heads.

Anomalyinva-
The head that you've had ported, what areas were ported and/or enlarged? Did you notice any areas that might have been in filled as opposed to opened up?

 

[gimmie11s]

I'm a roadracer, not a drag racer.

This is why you are partial to the stock head....and stock cams... and a 16g.... and so on and so forth.

I feel myself agreeing more with RapedApe. I am trying to go 130 mph in the 1/4. A worked head WILL help this venture. I think the question is which head to go with...1g or 2g.

I could care less how well my car turns. Frankly, if i did, i would not campaign a DSM. I would probably spend money on a wild N/A Honda or an e36 M3 or something along those lines.


-d

 

[Robster]

Ha, good points by all, but for a second there I thought I was going to need my flame suit.