I've been out of the car scene for a while but I'm looking to get back into it this summer with a new engine and I'd like some advice. I'm looking to build a 383 and I'd like to put 450 to 500 hp to the ground. Problem is I'm not sure if I can do this within my plan. I've got a good roller block as a foundation and a forged crank with 6 inch bushed rods to start with. Trick flow 195 heads and 1 3/4 slp coated headers as well. Now I'm planning to keep it na and keep the factory fuel injection and I've got a t56 too. Now I'm sure I'm looking at somewhere in the neighborhood of 11-1 compression and a pretty healthy cam to do this but I'm just looking for opinions about what direction I need to go.

 

I have 410 RWHP on my 383, ported 195's and 12:1 .GM 847 234 /242 cam ,
perfectly streetable but suspect if I do a cam change to get to the level you seek ( heads flow to .600 but only have .560 lift at present )
it will be less ECM friendly ( lack of local good tuners ) and need a carb

 

450 to the ground will need a good bit bigger heads. Those headers may do it if atleast 2.5-3" collectors into a good exhaust, single 3.5-4" ypipe all the way back. Or possibly dual 2.5's. 3" dual is abit overkill but certainly wont hurt much.

If you have a LT1 intake, port it out some to match the new heads you will need. Figure a good minimum 210cc, maybe even 220cc with a small valve. The head I'd choose for this would be Speier Racing 215cc small bore heads... Designed for 355-383 motors. Its got a large 2.50" sq cross section and flows around 306 at .700. Very solid head. Very nice valve train package starts at 1635. Pricey but thats the type of head you need to put on a motor to make 450whp.

AFR 210 may do it as well. I've seen a 370 motor with properly matched intake/cam combo make over 470whp with super comp ported 210's. Those heads are 2000+ bucks tho. Regular 210's can do 450whp but will need more cam to get there.

Pro-Filer also has a nice 210cc head that should work as well. Probably abit better than AFR after 6300 rpm on a 383 due to slower air speeds. Get it thru Speier Racing and he does alittle port work and adds matching valve train to your cam needs for 1595.

Now you could send the TFS 195's off for a port job and open them up as much as possible but i"m not sure how much they will support. Need a fairly large CSA on a 383 to pull the rpm needed to make over 450whp n/a. Total Engine Airflow could port them but you will be spending a good bit on porting that it may be easier to just buy the right head.

Other option is to run closer to 11.5 to 1 comp, and cam the crap out of it with ported LT1 intake and spin it to the moon. See how much you can get out of those heads but I dont think it will do much more than 430. I could be wrong tho. I'd just hate to see such an overcammed small head motor on the street when it could be done with a simpler hyd roller and GOOD heads.

 

Can you link to which cylinder head you're referring to? I talked to Chad yesterday and I'm going to give one of his heads a shot. Putting my money into a pair of those instead of stroking the motor out seemed like a better idea.

 

The 215 small bore head.
http://www.speierracingheads.com/SRH2.50BUDGET.htm

Pro-Filer econo ported
http://www.speierracingheads.com/profilerecono.htm

 

Apparently the first one only comes in 68/72cc chambers? I spoke with him about the econo ported heads. Is there any reason to choose one over the other, really?

 

They can be shaved to 64-68 cc i believe. As cast I think the core comes in 72.

Between the 2, the larger 215 will support abit more rpm. Flow is good between the 2 of them, they just use 2 different cores, one is American one is Chinese but its a good quality casting for once.

Both I think can do 450whp if you have enough cam/intake to support the high 6K rpm range you need to turn. Cant go wrong with either head tho for an application like this. The pro-filer 210 has made 580 on pump gas builds in the 383 range according to Chad's dyno data. 580 flywheel on engine dyno is darn near 460whp depending on what drivetrain losses you have and what accessory losses you have on the motor.

I had a 195cc AFR 383 that turned 6250 peak rpm but held power to 6500+ and I shifted at 6800. 400whp thru an auto. Likely an easy 410-420 in a T56 car. I would NOT hesitate to run more cam and definately larger head on a street 383 like that. That car although very aggressive at idle, was actually extremely tame to drive IMO. I'd go larger and make peak power closer to 6600. Vetteoz's setup is similar. 847 is a nice sized cam but you could do better today with custom lobes. Finding another 30-40whp tho is no easy task but guys have made 430-440whp with similar 847 cams on LT1 383's I've seen with very nice ported LT1 heads.

 

My goal is to hit the 400 RWHP mark with a 355 (not because of the magical 400 mark, but to see if I can actually do it and be streetable). I'm curious to see if I can achieve that with those cylinder heads and a bigger stick. I'm running a flat tappet XE274 right now, but I've got a Crower cam that's another size up (238/242@50 with 490/490 lift @ 1.5 with a 108 LSA).

I talked with Chad briefly, but that guy KNOWS his stuff. I've talked to everyone, and he's a no BS individual. He'll tell you like it is, and people are saying REALLY good things about the cylinder heads.. and more importantly - who developed them. I think a lot of R&D time went into them, and that's pretty damn good if you can get a 23* head to flow up there in LS1 terrority while still maintaining good velocity for a strong powerband all the way through.

 

Some of his larger heads will beat alot of LSx heads in power potential. I got a set of his V2.72's that can make 800 hp on the right 400" motor. Lsx heads take some work to do the same thing so that is saying something for his 23 deg stuff. His 2.72's are going on my 401 twin turbo build. I fear my fuel system will not be enough.

For a 355 and 400whp, do the pro-filer econo 210. Its way more than enough for that. If you could get a roller cam in there to take advantage of the lift, you could run high lift shorter duration, make big power numbers and keep it much more streetable at idle and low rpms. No lack of vacuum and such from larger cam durations.

But you should hit your goal with a cam in that range regardless.

 

What size valve would you recommend? I don't know much about his cylinder heads, and I want to ensure I have good port velocity consistantly. It's tough to say because they designed their cylinder heads differently, and I honestly have no idea what they changed to get such a great head (especially out of an as-cast head with minor work!). He said the difference between the two doesn't really matter because (like AFR's) you can take the 195's and port them out much bigger if needed. I really want to try these heads by the end of the year. I just saw them yesterday and I REALLY like the information I'm seeing on them. The price is awesome for what you're getting; albeit not cheap overall.

+ any idea if he ports intakes if we send them in to match the heads? I'd like to do that, also.

 

Wicked idle but very streetable
847 was a cheapy purchase from the Forum and biggest I had that I thought I could run on the street
Peaked at 6200 and dropped 10Hp to 7K
Hope it was the cam peaking because I have a Lunati 243/251 .560 HR and Comp 251/251 .630 custom SR to try when becomes track only engine

My 195's were done by LE so suspect they are probably near the top end of what is achievable

Finished intake port volume 205 cc’s

Intake Flow

.200 @ 140
.300 @ 200
.400 @ 245
.500 @ 274
.550 @ 280
.600 @ 282

Exhaust port finished volume 76 cc’s

.200 @ 108
.300 @ 144
.400 @ 176
.500 @ 190
.600 @ 204

What max HP do you estimate on those flows?

 

cheapest way to build t a 383 is get a 350 block...which it sounds like u have. get a 400crank and a good cam n lifter kit (i like Lunati but its preference) you can start there and do different things. you can cheap 350 block on craigslist, ebay, newspapers, swap sheets, swap meets at car shows (they will be starting soon as winter is leaving us early). just my idea of where i would start. you can play round with pistons and rods and maybe bore it out if you want.

this was just my

 

You can do what your looking to do with a 2.02-2.05 valve. I like the 210cc heads with 2.05-ish valves on a 4.030 bore. Any bigger and its starting to get alittle more shrouded although 2.08 can work. AFAIK the 195 and 210 start as the same core but the 210 is ported abit more. The port shape is slightly different with the slightly larger cross sectional area and laid back short turn radius so it cc's more and flows a tad more.

He does do intakes. Pricing is on the site if I recall. Port match is possible for few hundred. Full blown intake job can be up to 500-600 depending on what needs done. Pricey but all hand done and well worth it. Seen some good gains posted by him and other guys porting their intakes but they are usually carb single plane intakes.

If you go by the typical 2.2 hp per cfm, those heads should be 620 hp but it doesnt always work like that. But they look like they are very strong with good low/mid lift numbers. My friend has a set of old 195 AFR's ported alittle that flowed 286cfm (stock i think they were in the 260's) and he made 450-460whp I think with a miniram and solid roller in the 242 deg range on a 406. Thru a T56 manual. So a good 205-210 cc that has a CSA in the 2.1-2.2 range and flows over 280cfm SHOULD have it in the bag but you need abit more duration and good bit more lift on a 383 to get there. Then again thru an automatic trans, 400-420whp is very strong. Thats just about 430-450 on a manual trans car all day long.

Lloyd knows what he's doing with heads so I'm sure they are very capable in the right hands. Just needs a better cam suited for the combo and an intake thats not gonna hold it back any.

Your 847 cam did about the same curve as my 230/245 custom grind. Wide duration split held onto the top end very nicely from 6200 to 6600 where the run stopped recording which was strange because my limiter was set to 7K and we hit that on the dyno but it only showed 6600 rpm. Duration around 230-234 deg will get a 383 to peak in the 6200-6400 range with ok heads. Do get much higher you need to look closer to 240's. Lunati 243/251 .560 HR sounds good to me, just hopefully that cam can take a 1.6 rocker to make that .560 closer to .597. I think that will wake it up well.

 

Thanks for the replies guys. I'd like to stick with the trickflows if they can be ported to deliver the goods. I've already got them and I know they'll work with the lt1 intake. Is there enough material to port that intake? I thought that was one of it's downsides. I currently have 3.42 rear gears but I'm looking to go with a set of 4.10s so I think that and the manual trans should help with the cam I'd have to run. Definitely keeping the fuel injection as I don't like carbs anymore but I do have a guy close to me that has a chassis dyno to tune it. I have a set of crane roller rockers but they're only 1.5 ratios. I'd like to be able to run pump gas too. With aluminum heads do you think I can pull that off with 93 octane? I don't really mind a big cam and reving it to much as it's not my daily driver anymore.

 

Yeah 383 with 11 to 1 is a standard with 93 oct and decent cams I wouldnt build a 383 with aluminum heads that did not have 11 to 1 comp if going for a n/a build.

Since you want to keep those heads, I'd get them ported by either TEA, Lloyd Elliott, or maybe Advanced Induction if they have a program for them, or some other good head porter. Then go get yourself a nice hyd roller. 1.5 rockers will work but I'd like to see closer to .600 lift which is found with 1.6's typically. But you can get high lift lobes for 1.5's if the application requires it.

For an LT1 intake cam, I'd contact Bret Bauer from Bauer-Racing. He's great with LT1 engines. Advanced induction can do it too. I'm thinking 240/243 on a 108 lsa or something close to that. I had a cam like that spec'd for my 383 to peak near 6500rpm.

 

Ai doesn't do standard SBC heads. I already asked them about it awhile ago. Wish they did. He recommended me to someone else (can't remember who it was).

Oh, and FWIW: Spoke with Chad again today. Chad says the 195's are a better choice because you can grow with them much more than a 210cc head (something like 240cc's he said if I recall correctly).. something which is perfect for my situation as I won't be with a 355 forever.

 

Kinda surprised to hear that. He told me he hardly recommends the 195's because any motor that can use a 195 can get away with the 210's since they arent too much different. A 210 isnt too big for a hot 350sbc so it would offer more room for growth IMO but he knows his own heads best

The 195 core likely has more material left over in the port to shape to his larger 227cc shapes that are awesome on 400" motors. The 210 I believe was slightly modified from the 195 shape or so I thought. Slightly laid back SSR and wider throat/bowl or something like that. I dont think you could can much bigger with that casting? His larger stuff is based on RHS heads, i believe the RHS 220. I know my 245's are. He has a 230-235cc offering based on another import core thats proving to be a nice casting.

At first he was alittle conservative with my motor. I was considering the 210's or 227's and he thought the 210's could work or possibly the 227's but later after talking to the cam guy, he said I couldnt go big enough with a turbo car. I followed that advice thinking with proper cam specs and good velocity profile of these heads, I should still have plenty of overall power to cruise around with and they will give me room to grow. I'm glad I got them although double the money I wanted to spend, but hope they prove to be as powerful as I think they are.

 

He only said they are "better" because you can remove more material if need be compared to the 210 as they are different castings. I asked this question because I initially just wanted to jump on the 210's, but he said go with the 2.05 valved 195cc head. If I ever go with a bigger motor, just send the heads back and he'll respec them to feed more cubes.

I wish I had the money to throw down on this set right now. Had things gone my way with other stuff I totally would have, but such is life. :[

 

Makes sense I guess. The 195 is really a good head and will do what you want and if you go bigger, then having him touch them up is your best bang for the buck.

 

took me a few days to get back here but What I'm seeing is my power goals are reachable but I'm going to need more airflow. As I said I'd like to stick with my trickflows if they can be ported enough to flow the air I need. Any recomendations on porters? the ones already mentioned don't seem to do sbc heads, at least that's the impression I got from their website. I'm going to try to make some call next week to verify that though. As far as cams go I'd like to stick with comp cams as I've had pretty good luck with them on other occasions. I'm not averse to using someone else though so I'll listen to any opinions you guys would like to share. Thanks for all the help so far and please keep the suggestions coming.

 

Chad Speier perhaps. TEA should do them. Maybe Lloyd Elliott, have to ask him. Have to shop around and see who's doing what.

I think you can get your goals with ported TFS 195's. Just need a good cam/intake to make it all work. 450whp is within reach on a hot 383.

 

Tea,s website seemed to suggest they don't deal with sbc heads anymore but I'll call or email them monday. I'm also going to call Speierracing as well. I haven't heard of the last guy mentioned(like I said been out of the scene for a while) does he have a website or contact number? Do you think my intake can flow enough air unported? I saw one responce mentioning porting it as well.

 

never mind, I just found him with a gis. I'll definitely get in touch with him this week. Thanks for the tips guys. I'll post up any new info in the coming week.