CORKVETTE1

beach if that bottom intake is stock then it only flows around 220 cfm where the top end with the runners flow around 260-270 I know for fact I would start with the bottom intake the same heads i have on my vette now the no lie one is 190 cfm the other is 195 cfm untouched and I mean untouched beside being cut down to 58 cc 202 and 160 valve went high 10s on my camaro carbed motor still only 330 gear 3400 converter with a race weight of 3300 empty without my 225 lbs in it here is a link of it check it out http://hometown.aol.com/corkvette1/m...age/index.html
so what I am getting at you should be looking other places too just not the heads I never really like dart heads but if yours are flowing that good I would try other things first

gkull

If your SR can match up to FelPro 1206 gasket size I think that the AFR 210's with big valves would be the best choice.

I have never had to work on a restrictor plate motor (S/R and such a low red line) Just from logic I would think that for a certain port flow that allowing it to flow longer. Like in longer duration cams will fill the cylinder better.

Aluminum has 3 gains over nearly every iron head. Weight, chamber design, and the heat loss and lack of efficiency can all be regained through modern high tech thermal coatings. I have thermal coated piston tops, chambers and exhaust valves. I didn't research it enough before I did mine. I have since changed on what I would do next time. The leading edge companies also coat the intake and exhaust ports and have oil repellant coatings on everything under the valve covers.

All the coating companies claim knock resistance raises. I was skeptical so I set my c/r at 10.84. Now I wish I went 11.5

Beach Bum

My Accell base intake is completely untouched. I'm not totally sure whats been done to the plenum and runners, I bought them from Bowtye8 a while back and he had said he has massaged them a bit... not sure how much. Had nothing to compare too.

Corkvette, are you saying the base then only flows 220cfm... if yes, it certainly sounds like I'm losing out on quite a bit of power with the untouched base.

I'm kinda leaning at doing this in stages, maybe start off with the SR port and see what that does, and then follow with the heads. More work for sure, but would be interesting to see the results with no other changes.

Thanks for the input guys.
Beach

CORKVETTE1

yes the base is only 220 cfm it was in an old car craft I think with lingenfelter doing the testing ill have to dig it up but they extrude honed that base and got 275 cfm so what I am saying is that bottom intake is probably a pretty big restriction the top end isn't that bad even stock

89gta383

Corvette, can you dig that issue out and see if they hand ported the intake or just had it extrude-honed? The guy I talked to, Bob Jones, said to tell the extrude hone guys to open up the runners to 1 3/4, and that they would hand port it also, and then run the gooey stuff thru the intake. He said that he has seen close to 300 cfm's out of one.

What month and year was that CC issue?

Cory@LS2PortWorks

Another advantage of the MR over the SR is another 18lb weight reduction on the front end. By my fish scale calculations... the SR weighed in at 38 lbs while the MR weighed in at 20. I've switched to the MR by the way.

Cory

ralph

i just found a post that Beach put up in the Dobbs forum back atr the end of 1998...lol He retyped the flow data from the CC or GMHTP mag flow results:

stock base = 222cfm
SR base = 252cfm
honed SR base = 276

stock runners = 207cfm
accel LT runners = 242
honed LTs = 276
SR runners = 289

SR runners on SR base = 240
honed base and honed LT runners = 267
honed base and SR runners = no data , but you could guess it would flow around 270-275 (can't flow more than the base).

maybe there is another article floating around...i love to see the numbers.

Beach Bum

Ralph,

How'd you find that ?

I was actually going to look for the Hot Rod issue that I got that out of. The tests were performed by well known tech writer Ray Bohacz and was printed in a Hot Rod magazine a few years ago under the title "10 deadly EFI sins"

Corkvette, where did you get the 220 cfm #'s... big difference between 220 and 250 as you know. It looks like the factory base only flowed 220 stock though.

LPE advertises 15 HP in their catalog for SR base, runners and plenum porting. I tend to think, but could be wrong, that their #'s are more on the realistic side of things compared to some of the other tuner claims.

I'll find out what they flow before and after later this summer or in the fall.

Beach

CORKVETTE1

i could be off on the numbers a little but they extrued honed it then it went to 275-280 cfm i still have to find it but the point still being there is more to pick up in that bottem intake than in your heads

ralph

Beach, i actually had the foresight to print that post cause i figured i'd be looking for those flow numbers some day...LOL

That is kinda where i was coming from...i always had in the back of my mind that the SR only flowed around 260-270cfm...so installing heads that flow more wont help, in fact if their cross sectional area is larger then the SR it might actually hurt. Maybe if you port the SR and then hone it, maybe it can flow 300cfm. The article said nothing about porting.

btw, I got my heads back today. They look great. he did a 5 angle valve job and a little bit of bowl work...so they might flow a little more than before. Unfortunately, it looks like i got some more port matching to do on the head side of the intake. It is a tricky fit with the small race gasket. i've got to install the gasket a little low so the top of the intake will seal. The good news is there might be some performance there, but the bad news is it's a lot of work!!!!!!

The guy at the shop said that he's been able to get over 300cfm out of a 190 head, but its a lot of work (larger valves and a lot of material removal, and welding). i think he said the runners were enlarged to around 220-225cc. he quoated me about $1000 plus parts (new valves, seals, etc). You are probably best off going with the comp ported 210s or 220s and have the SR base modified to fit and port the crap out of it.

does anybody know if AFRs comp porting increases the runner sizes? for example is their comp ported 190s, still a 190cc runner?? if not, be careful cause their comp ported 220, might be 230. If the runner are the same size, then the race ready version must be an inferior CNC program????

Beach Bum

I think I'll end up going the traditional AFR 190 route and let the porter cut it down to 54-58 cc chamber and open up the runners to a max of 210 and whatever it ends up flowing... it flows. The loss in weight combined with the increase of compression is gonna help a solid tenth at least I would think... and maybe even a couple.

Though I do want to have a second look at the Brodix Track 1's. Does anybody know of anybody running these ?

But before I do the heads, I am probably going to go ahead and have the SR ported and see what that does for me if for no other reason... curiosity.

thanks guys !!
Beach

Beach Bum

Ralph,

Congrats on getting the heads back... can't wait to hear your new track results. Did your head guy have anything good or bad to say with your current port ?

later
Beach

ralph

if you are refering to the 190s, he said they were a pretty good head and that is why it takes some work to make significant improvments. he can easily make improvements to stock heads, but many of the std improvments are already there in the 190s. the bowls are 90% of the valve size...he said you can go to about 91 max, the runner shapes are nice, surface roughness about right, etc. My multi angle valve job from AFR was gone...basically one angle left...normal after a hard 10K miles. i'm a little pissed i didn't give him a spec for the chamber CCs. He estimated that they would wind up aropund 57-58, which would have given me about 1/2 point jump in CR, but it turn out they only had to mill them a couple of thou and the chambers are 59.5CCs, so no pickup in CR. Also never ever run tap water in you radiator. i only had tap water in there for about 6 months or 2500 miles, then switched to distilled water. However there was a lot of corrosion around the water jeckets and one of the passages were corroded right into the fire ring around the cylinder...it would have broken thru there soon. he grinded & rewelded that too. he showed me areas to make small improvements flow if i wanted to take a crack at it myself (roof of the exhaust port, side wall on the intake port). He stressed that you will kill the exhaust port if you flare it and to make sure that the entire intake runner has a larger section that the runners in the head. However, i think i'll leave them alone...i'm just about outa time. I've got tomorrow afternoon and friday off, and then i'm booked for about a month. so if i don't get it done by Friday, i probably wont see the track until the end of August. besides they look new again. I really wish i had time to get the intake & heads flowed. then i would know where the bottleneck is. right now i think its pretty balanced, so i would have to open the intake up before i did the heads, but i dunno!!!

anyway, if your base is stock, it's only flowing 250 at best (probably less with the runners) and your heads flow more, so you should see some improvement by porting the intake, but you know how that goes...never get your hopes up too high.

i would reconsider the 190s if i were you. IF...the runners on the 210s are compatible with the base, you might want to go that route. they'll give you more room to grow, particularly if ever move to the miniram.

good luck my friend.............

BBA

Beach... I think you should know Brodix will design heads to order...and they charge almost exactly what you can by the generic Brodix head from Summit for.

Call them, ask to talk to their head designer guys. Thats what I did. They custom made a set of 'Dragon Slayer' heads for me out of their 10 series head...port is like 200cc but flows it but off...and it's a 23 degree design at that.

I'm sure they will make you an 18 degree head with any port size you want.

Another BIG benefit of Brodix is they are solid dense aluminum...you can even TIG weld them to repair them...try that with a chevy Al head ( the chevy head will disentegrate )

Another really nice thing about Brodix is roller rockers will fit under STOCK valve covers. Thats because the valve cover flange is 1/2 inch higher than stock on ALL Brodix heads. Thats a benny of having a head port you can cut into the roof to make high port race head. ( IE: ALL SBC Moosehead Gran Prix cars run Brodix heads...ALL OF THEM )

Just a few thoughts.

I found Brodix to be a very helpful, very knowledgeable and honest company when I dealt with them.

Beach Bum

BBA & Ralph,

Thanks for the tips and help guys.

BBA, Brodix is a strong contender to get a piece of my wallet. I've heard the same from others about how easy they are to work with.

Ralph, Good luck getting it back together.

Regarding a 190 or 210 runner... it is a dilemna. But unless I pull the vette completely off the road, I don't see myself running it.... but who knows.

later
Beach

AKS Racing

The motor I am currently pulling from the car is a 350 ci motor with a set of TPIS Stage IV heads and SR. This combo used 1206 FelPro gaskets. My heads were angle milled to 51.5-52cc. This effectively rolled the intake port higher, and I have not had an issue with sealing the SR to the heads.

Someone asked if the AFR heads with the comp port adds volume to the runner. I just purchased the comp ported 210cc from AFR. I was told that the new head would be in the 215-220cc range. They measure 217cc. They look great. I stayed with the 210 because it would allow use of the factory valvetrain and thus the factory valvecovers. This would allow the engine to look more stock. When you step up to the 220 AFR head, whether RR or CP, you have to use either TD or Jesel shaft rockers. These rockers overhang on the intake side, so you have to use an aftermarket welded cover (i.e. Moroso) or a Chevrolet racing cover (like on the 18° heads).

I have a nice set of 18° heads that flow in the neaighborhood of 370 cfm according to Ron's (they set them up). The problem is that they you have to have a sheetmetal intake made for this. Maybe when I buid a truly large motor (i.e. 427/434), I will use these. I even have the stainless custom headers (1 7/8), correct valvetrain, valve covers, and a carbed intake to fit. But no motor to install them.

As for the AFR heads, I had a set of 190CNC that TPIS set the profile in the past. Good heads on a 350 (use 1204 FelPro). My machinist said that it would take $3-$4K to make them Possibly flow what the comp port 210 RRs flow and the 210 RR cost $1600. So I opted to go with the extra $374 and get the 210CPs.

Just my .02.

Thanks,
Aaron

ralph

ASK, i don't know how you got the stock SR to seal with a 1206 (med race) gasket. I just installed my intake last night with a 1205 (small race) gasket and i swear i have maybe an 1/8 to 3/16 sealing surface on the top and bottom (and that assumes it is installed perfectly). They fit the head perfectly (190s port matched to the gasket) and the base fits the gasket pretty good, but its ported to match there is very little material left to seal the ports. in fact you can see some of the printoseal at the top corners. it seals, but the installation has to be perfect. I curse LPE for not providing more material very time i install it.

have you ever flowed your SR??

HiTech5

Beach - Over the winter I had some work done on my AFR 190's. Most of the work was done on the intake side. The exhaust was just polished as well as the combustion chamber. He also gave it a valve job with a backcut on the intake valve. I don't have my before numbers in front of me but the heads were not heavily massaged by any means. Also the guy who did the heads said that he could pick up more flow on the intake side by unshrouding the valve but I did not want to lose compression so we left the chamber untouched.
Lift Int Exh
.100 66 53
.200 137 114
.300 192 155
.400 233 194
.500 255 207
.550 263 213
.600 269 215

Beach Bum

AKS,

Sounds like those AFR 210's that were opened up to 217's are the way to go when I pop for new heads.... do you have flow #'s on them, it would be interesting to compare to the #'s
HiTech generously gave.

HiTech, Those heads flow great on the exhaust side already from the looks of it, but I'd like to see another 10-20 cfm out of them without increasing the size of the chamber.

btw, where are you at in Elk Grove... I used to work in Elk Grove.

cheers,
Beach

-=Jeff=-

If I am not mistaken HiTech also has a pretty quick car too..

I believe I was lined up at Byron Once before..