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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Low compression with fairly big port aluminum head and a big flat tappet, i think it will be abit of a slug. I would use a xtreme energy type or lunati voodoo grind about 8 deg shorter. Think you'd be happy there. 108-110 lsa
Those heads are dirt cheap and you get what you pay for. If you get those heads i would have them checked thoroughly and put good quality springs in it.
I'd probly run gm vortecs before those, or buy them bare and have a good shop setup the heads with good valves springs and guides
Low compression with fairly big port aluminum head and a big flat tappet, i think it will be abit of a slug. I would use a xtreme energy type or lunati voodoo grind about 8 deg shorter. Think you'd be happy there. 108-110 lsa
Those heads are dirt cheap and you get what you pay for. If you get those heads i would have them checked thoroughly and put good quality springs in it.
I'd probly run gm vortecs before those, or buy them bare and have a good shop setup the heads with good valves springs and guides
With flat tops and 64cc combustion chambers, won't that be a fairly high compression? I was guessing 10.1:1+ and someone said he would guess it could be as high as 10.3:1
I was recommended the cam, and looked over the specs. It is a little bigger then most people recommend, but sounds like it will give plenty of low end for street tires.
One reason for the bigger cam is that we want a lopey idle. This is just going to be a weekend fun driver, so I like the idea of it. To me they sound great if they're not stupid rough.
I know you can't trust what you read, but White machine shop that sells them, says that they do put high quality springs. I believe I heard somewhere they use competition product parts. And at $161,(that's right off of ebay so I bet they get them cheaper) for a bare head(out of stock), they could easily use quality parts and turn a large enough profit.
We plan on dissembling them on arrival and doing a small port job with a die grinder.
Cheap castings with huge ports and cheap components seems to be skips MO unless you buy his top end stuff. I would ask for some sort of proof that he puts in competition productions items. My money would be on speedmaster / procomp stuff. The flow is absolutely shittastic for the 200CC port a stock 170CC vortec can flow the same. That cam and those heads I would expect it to be super lazy below 2700rpm. There are probably a dozen other cams I would put in before that one even a thumper if I had to have a crappy idle.
Cheap castings with huge ports and cheap components seems to be skips MO unless you buy his top end stuff. I would ask for some sort of proof that he puts in competition productions items. My money would be on speedmaster / procomp stuff. The flow is absolutely shittastic for the 200CC port a stock 170CC vortec can flow the same. That cam and those heads I would expect it to be super lazy below 2700rpm. There are probably a dozen other cams I would put in before that one even a thumper if I had to have a crappy idle.
I get that these are cheap, but everyone who has them seems to say they're surprisingly nice.
If I end up talking to him and finding out it's off brand china parts, I can buy the stuff and assemble them here just fine. The reason I chose these were because
1: Everyone seems to agree they flow very well for so cheap, and even better with a home port job.
And 2: I'm working on a college budget here. $100 between these and speedmasters is a big deal for probably just the name more than anything. I wouldn't think that those speedmasters off of summit have anything better then the nkb heads from white.
Did I say I wanted a terrible idle? No. I said I wanted a nice lopey idle, which I get that some(seems like most on here) don't like. Not these thumprs that people get to make there trucks and cars sound like the engine is about to blow.
Could you give some reasons why there are a dozen cams that would work much better than this? I have no doubt that if I wanted a nice smooth idle that there is a cam that would work better. The thing I don't understand is why people want 400 ft/lbs of torque at 3k RPM when that will just eat street tires all day. I want to take off and not just keep up with a civic to 5k RPM, but I just don't see the reason to have all of it down that low..
If people think 230cfm on 200CC is flowing well then they have never seen a good head. My biggest beef with these heads are the lack of info given. He lists his features
Hardened Seats (all heads after 63ish have these)
Bronze Valve Guides (standard)
High Grade Aluminum (really what kind?)
Multi-Angle Seat Design (standard on performance heads but how many angles?)
Available Complete or Bare
Available fully CNC Machined (lets see test numbers)
Designed Performance Valve Springs (Specs, brand?)
Advanced Port Design for Greater Flow (really 200cc 230cfm at 500?)
No specifics just an attractive price instant red flag. I have done the budget head thing and I am still doing it but I have seen a lot of issues over the years. Usually casting errors, pushrod alignment, cheap springs, valve stem wear and cracks on aluminum heads.
I have done the college budget thing and learned the best course of action is to wait another month or two then buy the better thing. BTW speedmaster is just procomp.
Reasons for a different cam, more HP and TQ at lower RPMS with a better idle and less wear on the rotating and valve train components. A little suspension work and some LCARCBs and you can fix a lot of traction issues. I bet that cam sounds almost exactly like a thummper cam but with more valvetrain nose due to being mechanical tappet with a slightly worse powerband.
But you already seem sold so get what you want and enjoy it.
I bet that cam sounds almost exactly like a thummper cam but with more valvetrain nose due to being mechanical tappet with a slightly worse powerband.
Mechanical also means you will be adjusting it. I adjust my Nova's every year and I drive it less than 200 miles a summer.
I may have missed it but I did not see screw in studs in the heads.
If it were mine, I would want the parts matched up better. In addition new convertor and maybe steeper gears, but that's just the old school in me. Maybe the 700 can compensate for that cam. Yes, I like the option of standing on it and spinning a 10" slick half a block (I can drop 4 lbs air and it hooks). I spent too many years driving a car waiting for the cam to hit it's power range and trying to play catch up.
If people think 230cfm on 200CC is flowing well then they have never seen a good head. My biggest beef with these heads are the lack of info given. He lists his features
Hardened Seats (all heads after 63ish have these)
Bronze Valve Guides (standard)
High Grade Aluminum (really what kind?)
Multi-Angle Seat Design (standard on performance heads but how many angles?)
Available Complete or Bare
Available fully CNC Machined (lets see test numbers)
Designed Performance Valve Springs (Specs, brand?)
Advanced Port Design for Greater Flow (really 200cc 230cfm at 500?)
No specifics just an attractive price instant red flag. I have done the budget head thing and I am still doing it but I have seen a lot of issues over the years. Usually casting errors, pushrod alignment, cheap springs, valve stem wear and cracks on aluminum heads.
I have done the college budget thing and learned the best course of action is to wait another month or two then buy the better thing. BTW speedmaster is just procomp.
Reasons for a different cam, more HP and TQ at lower RPMS with a better idle and less wear on the rotating and valve train components. A little suspension work and some LCARCBs and you can fix a lot of traction issues. I bet that cam sounds almost exactly like a thummper cam but with more valvetrain nose due to being mechanical tappet with a slightly worse powerband.
But you already seem sold so get what you want and enjoy it.
That's why I'm here. I'm not sold on anything.
They're saying 230cfm on a 200cc head is good FOR $170 a bare head. Obviously a $600 assembled head isn't going to be top of the line. I was just thinking with mild porting they would reach the power that I want out of it. It's going to have an almost stock 2002 10 bolt posi which isn't strong by any means. Which is why I'm not looking to really break much past 400CHP.
I get the little information part. We won't be purchasing anything without directly talking to him first.
I'd like to save up and get a better set of heads, but this car is going to need so much besides the engine that if a set of cheap heads would get to that 400ft/lbs mark, it'd make life so much easier. I mean we still need most of the car. Wheels, air ride if we decide to,(VERY bad roads here, and our driveway is like 1/4 mile long gravel pit) paint job, tranny, etc etc. I don't want utter trash, but I do want the cheapest quality heads that will get the job done.
Sorry about being snappy in the last post. Not talking about you directly, but it seems like everyone has a reason to hate these heads. They flow bad, they're cheap china castings that are gonna crack after a month, they use trash parts, etc etc. Criticism is all good. Saying this but then leaving the thread without saying what heads would be worth it, what to look for in heads over these, etc is what everyone does though. Or saying this then recommending $2000 CNC ported AFR heads.. Lol.
I think people were against it because of the unknown quality of the castings, and the relatively bad "advertised" flow rates. We have all seen bad castings, and a lot of people don't want to take a risk with a set of heads like these. Up to you on the risk, be sure to let us know your results.
Vortec's are a dime a dozen, and we know how they flow on a lot smaller port. I bought mine for 75 bucks on ebay, and sunk 200 in valve train and have a pretty good set of heads. PicknPull has 1/2 price weekends and you can pull a set for $34. That being said a lot of them are cracked so you have to be careful with them too.
Your static compression ratio will be somewhere around 10.1. Depending on the overlap of that cam, it could bring your Dynamic Compression Ratio down. Combo'ed with heads with large 210 ports you will be left with a motor that is a turd until you get in the RPM's. Fine for a race car, but may not give you the feel your looking for (even though it has the sound).
I am helping a buddy doing a LS swap to replace the 350 he built very similar to that combo. He used procomp 210s instead (similar flow numbers), and a cam about that range. He loved it, and ran the hell out of it, but eventually broke a piston skirt, a result of over-reving it racing a mustang. The motor loved high RPM's, and that's what eventually led to it's demise. Rev limiter is a must have!
Holly mole just looked at the specs on that cam. 238/240@.500 .531 lift on a 107 LSA mechanical flat tappet. That is a monster of a cam, for short track cars.
I would look at one of summits hydraulic flat tappets save some money to put into the heads. Just my opinion.
I would reconsider the parts selection. Seems 238/240 like a lot of cam for a 350. What gears does your car have? I would want 4.10 at least. I would ask Howard's what cam they suggest for your set up. I would ask whites the same question.
I have a 230/236 in the 400 in my vette.
I think an Isky 270/270 Mega Cam would be a better choice for a weekend car with a 350.
As for the heads, I would save my money and buy something else. Heads are the most important part of making hp. If you buy those heads I would have a trusted shop check them very carefully. Personally, I rather wait and buy proven quality heads.
One forum says it's pretty good all over, and gives all of the stuff I need, then the next says nothing there is good. Lol.
But I know that most of what was brought up here is true.. Just makes life that much harder.
For the heads, I'll take into consideration everything said here and look around for a higher quality set in my budget. I guess I'll end up with what I'll end up with.
I did use the cam recommendation form from howards. The response I got was pretty much, get out until you know for sure what heads your getting. Which I guess is true..
And lastly, about the heads from white being set up for hyd, I thought I already said I was going to ask them about that, but I forgot. they sell a set up for rollers but not for solid FTs without calling first.
If you don't mind, and to spare anyone from having to re-read all that's written here, what exactly is it that you're after?
What I'm getting up front here is that you want a engine that idles like it means something. You're willing to sacrifice good street manners and driveability for the sake of the sound. Is that about right? Lots of people are after that very thing. This is precisely why Comp introduced the Thumpr series of cams. Mind you, that cam profile, despite it's exhaust note, doesn't necessarily mean that it has to be a piece of crap at lower RPMs. The assembly of parts still have to complement each other. (I'm not recommending the Thumpr, I'm just pointing that out.)
The other thing I'm getting is that a tight budget is really a limiting factor.
Is that about right?
If it is, budget wise, there are plenty of options. None of which have to limit you going forward. As for the sound, there are ways around that too. Something to consider though, is cams with specs as the one that you originally posted can be tuned so that the idle isn't necessarily all that "lumpy". It just takes someone who knows what they're doing so a word of caution in that regard. On the flip side, lesser cams can have that sound too. It just means that something isn't quite working as it should.
I can tell you this. An engine that's built properly, one with compression to match the cam, with the right ignition timing, sounds awesome. Even non-car people take notice. It just sounds "right".
If you don't mind, and to spare anyone from having to re-read all that's written here, what exactly is it that you're after?
What I'm getting up front here is that you want a engine that idles like it means something. You're willing to sacrifice good street manners and driveability for the sake of the sound. Is that about right? Lots of people are after that very thing. This is precisely why Comp introduced the Thumpr series of cams. Mind you, that cam profile, despite it's exhaust note, doesn't necessarily mean that it has to be a piece of crap at lower RPMs. The assembly of parts still have to complement each other. (I'm not recommending the Thumpr, I'm just pointing that out.)
The other thing I'm getting is that a tight budget is really a limiting factor.
Is that about right?
If it is, budget wise, there are plenty of options. None of which have to limit you going forward. As for the sound, there are ways around that too. Something to consider though, is cams with specs as the one that you originally posted can be tuned so that the idle isn't necessarily all that "lumpy". It just takes someone who knows what they're doing so a word of caution in that regard. On the flip side, lesser cams can have that sound too. It just means that something isn't quite working as it should.
I can tell you this. An engine that's built properly, one with compression to match the cam, with the right ignition timing, sounds awesome. Even non-car people take notice. It just sounds "right".
Thanks.
You pretty much hit the nail on the head. But honestly, I won't give up speed for sound. If it was like having to run 93 octane or something but it would still take off like a rocket, by all means. But if it's the difference between slug at 2900 rpm vs great performance that low, I'll live without the sound..
I know a lot of people don't like the sound, and even more get hated on getting a bigger cam to have the sound. This car is what I got. I always wanted a 1st gen or second gen at latest, where the big lopey idles and loud exhaust was the norm.
I'm not saying I don't love the car, and I wouldn't trade it for most anything.(alright, maybe a 1st gen )
But it's going to be out, t-tops off just cruising once or twice a week. I want a mean car for that. Show the new mustangs who's boss. Atleast the V6's.
Going at it with the items listed, in particular, the cam, you will do just that. Sacrifice speed for sound. The recommendations above have largely been trying to steer you away from doing that.
Let's approach this from the list in post #1.
Heads: My understanding is that they're plagued with quality control problems. What I have heard is that they're not a bad place to start in terms of bare castings. Then add to that all the good stuff to make them right . Quality valves, springs and hardware, revisit the valve seats and possibly guides, clean up the ports, etc. Soon the budget is gone.
Cam: Simply put; it's wrong. What's more, you may not get that sound that you're after. And it will most definitely put you in the category of sacrificing speed for sound even if it does give the exhaust note you're after.
Intake: Good. Note the RPM range.
Carb: Good. Keep it vacuum secondary for your objective of street use. Maybe the 670 Avenger by Holley.
Headers. Keep them 1 5/8". Budget says a pair of mufflers dumped before the rear axle. And to tell you the truth, despite the noise and the exhaust fumes, it's one of the best systems going providing the lengths are right. (More on that later if you want).
Recommendations.
Heads: Someone mentioned Vortecs. Best bang for the buck and they're cheap if you shop around and can find something already modified to support the cam. I sold my old set, complete with screw-in studs, Comp beehive springs and acceptable valve guides for 500 bucks. Those deals are out there.
Regarding the E-Bay heads, their quality notwithstanding, those big ports and from what others are saying, are lazy ports and could be real slugs. Beware on that purchase although at least they have right sized combustion chamber at 64 cc (if that's indeed true).
Personally, I'd shop around. At least for a smaller ported head.
Cam: If it weren't for your desire to have that "sound" then I'd follow just about any of the recommendations above. Personally for a street driver, where you want that jam at light throttle, I'd limit intake duration to around 224 @ .050". With a 10:1 compression ratio engine, it makes for a snappy ride. No V6 Mustang would stand a chance (maybe).
But...and I only say this in deference to your "choppy idle" request, take a look at the small Thumpr cam Comp has. The intake profile is just about right. It's the exhaust that makes the difference here. I've read a few reports on dyno numbers and while I can't vouch for the credibility of those reports, they seem to make decent power. Note the RPM range. You just have to be sure that you match the cam to your compression ratio.
Speaking of which, you need to get more specs on the "stock bottom end" you posted. Stock what? Piston volume? Deck height? All of this is important to know. And while you don't have to change it (taking your budget into consideration), it'll help to build to it.
Just a few thoughts to try and confuse you even more.
If it were me, (and it has been), I build for performance (and economy) and aren't too concerned about the sound image. I'd rather kick your *** on the street than in the parking lot.
For you and others here, check out these cam specs comparing Comp smallest Thumpr to a traditional and widely used street cam. Keep in mind that the Thumpr is a flat tappet hydraulic (budget orientated) compared to the hydraulic roller. If you had a roller block, I'd say skip the flat tappet altogether.
XR276HR. Note the intake events compared to the Thumpr.
Thumpr. Note the exhaust events compared to the 276.
I'm not recommending the Thumpr but am saying that if the exhaust note is the deal here, build to the strengths of the Thumpr and have at it.
You pretty much hit the nail on the head. But honestly, I won't give up speed for sound.
Well that is the opposite of what you said before but exactly what we have been telling you what you will do with that combo.
Personally for a street if you really want something wild but streetable the XE284 is about the limit I would go with. The 274 or 268 with some 170ish cc vortecs will make a ton of power and be a damn good time. Also easy on the budget.
Although I want to point out do NOT cheap out on roller rockers. If you wan the cheapest decent rocket go comp cams high energy about $160 a set.
Well that is the opposite of what you said before but exactly what we have been telling you what you will do with that combo.
Personally for a street if you really want something wild but streetable the XE284 is about the limit I would go with. The 274 or 268 with some 170ish cc vortecs will make a ton of power and be a damn good time. Also easy on the budget.
Although I want to point out do NOT cheap out on roller rockers. If you wan the cheapest decent rocket go comp cams high energy about $160 a set.
I read all that skinny wrote and am doing a bunch of research of my own before asking anymore questions.
As far this, I never wanted to give up power for sound. If I'd be losing like a few ft/lbs down low and gaining the sound and a bunch more up top power that I'd likely not use a lot, I'd be fine. If it's as bad as you guys are saying, I'll have to change my mind.
I haven't even looked at roller rockers.. I just expected them to be about $175 and tried to forget about them until the time comes.. lol..
Just thought to put this out there, the person I'm in contact with from howard's says go with 200cc for a street 350.
For that cam or just in general?
For that cam I would say yes 200 because you are going to need to rev the **** out of it at all times. For a normal streetable 350 I would disagree. Then again normal 200 heads flow about 15-25% better so might be OK although still lazy in the low end.
For that cam I would say yes 200 because you are going to need to rev the **** out of it at all times. For a normal streetable 350 I would disagree. Then again normal 200 heads flow about 15-25% better so might be OK although still lazy in the low end.
He's talking about in general, didn't mention this cam yet. I did mention a lopey idle, but also said I would not sacrifice performance. So I'm thinking all around.
There don't seem to be ANY dyno tests or even first hand experience in 200cc vs 185cc on a 350. 383 there are, but no 350. I just want to see how much is actually lost down low from the 200cc.
Just thought to put this out there, the person I'm in contact with from howard's says go with 200cc for a street 350.
Funny thing about that. Ask a dozen people for their definition of a "street" engine (350 or otherwise) and you'll get a dozen different answers.
Originally Posted by mattbhm
He's talking about in general, didn't mention this cam yet. I did mention a lopey idle, but also said I would not sacrifice performance. So I'm thinking all around.
There don't seem to be ANY dyno tests or even first hand experience in 200cc vs 185cc on a 350. 383 there are, but no 350. I just want to see how much is actually lost down low from the 200cc.
You haven't looked far enough. I know there are loads of cylinder head tests aimed at the 350 and various head configurations.
In your case, compare head flow data with what you are considering. Here's a link to website that has dozens of SBC head profiles. What to look for in particular is head flow vs port volume. Generally speaking, equal flow with a smaller port yields better results from a street perspective. (There's that definition again).
Check out this website for your research.
Chances are you won't find your heads listed. However, if you have flow data for the E-Bay heads, be sure to consider the test bore diameter of the equipment used. Remember that a large test bore (example 4.200") will inflate the flow values compared to a more standard test bore (4.030"). It'll make more sense when you check it out. Ultimately what you're looking for is flow vs port size. Particularly the low lift numbers (.200" and less). That'll make low engine speed torque which is something you'll appreciate on the street. Again, the lopey sound factor is something to work around and try to incorporate.
(PS. My 288 cammed 355 has barely any lope but the sound, to most, is pretty nice. Compression ratio helps a lot here).
I will look into trying to find more info on the pros and cons of smaller and larger runner size.
I will also check out that link for information about flow.
IIRC, the heads I linked are the same casting that midias posted(assault racing) that were so well received by almost everyone here for their great quality. Could be wrong.
As for the cam, I'm not going to pretend I know anything about cams, but I have just now done some research, and was told, that the duration @.050 lift will be much higher on the card due to lash as it is a solid ft. As much as 8-12 degrees higher. If that's the case, that would make that cam a much more reasonable 226-230 in and 228-232 ex.
But like I said, still learning so could be very wrong.
Do you know what piston is in that shortblock? How far below the block deck it is too? (Howard's would have made some kind of assumption given they're agreed with your combination).
No opinions but I would like to know what the final compression ratio is likely to be and how it relates to the cam you've selected.
Do you know what piston is in that shortblock? How far below the block deck it is too? (Howard's would have made some kind of assumption given they're agreed with your combination).
No opinions but I would like to know what the final compression ratio is likely to be and how it relates to the cam you've selected.
Stock L83 Flat tops, 4.3cc reliefs.
I am not positive about the block deck, but I will do some research about how to check.
Having had a good second look at the cam, it's not really as big as the numbers suggest. The advertised duration values are very short (266/268) compared to the .050" numbers (238/240). The tighter LSA of 107 and the ICL of 102 are what makes this cam interesting.
Running it through a DCR calculator shows that it would like a static compression ratio of about 9.5:1. That's not a lot and might play right into the L83 shortblock.
Having had a good second look at the cam, it's not really as big as the numbers suggest. The advertised duration values are very short (266/268) compared to the .050" numbers (238/240). The tighter LSA of 107 and the ICL of 102 are what makes this cam interesting.
Running it through a DCR calculator shows that it would like a static compression ratio of about 9.5:1. That's not a lot and might play right into the L83 shortblock.
It really looks like howards is trying to recreate a thumper cam in mechanical flat tappet. The LSA and ICL of 107 and 102 are the bread and butter of the thumper line. Keep compression around 9:1 they don't like a lot more as the low LSA tends to increase the chance of knock and raise cylinder pressure. It will probably make **** for vacuum so there is a chance your power brakes will have issues. A lot of those cams only make 6-8in at about 1k RPM. It will sound nasty that is for sure but it will basically be the same as a fart cannon on a civic. Lots of noise and no real performance. Although I bet it turns heads when you idle down the road.
I would look into if they have a hydraulic version so you don't have to putz around with adjusting the valves a lot.
It really looks like howards is trying to recreate a thumper cam in mechanical flat tappet. The LSA and ICL of 107 and 102 are the bread and butter of the thumper line. Keep compression around 9:1 they don't like a lot more as the low LSA tends to increase the chance of knock and raise cylinder pressure. It will probably make **** for vacuum so there is a chance your power brakes will have issues. A lot of those cams only make 6-8in at about 1k RPM. It will sound nasty that is for sure but it will basically be the same as a fart cannon on a civic. Lots of noise and no real performance. Although I bet it turns heads when you idle down the road.
I would look into if they have a hydraulic version so you don't have to putz around with adjusting the valves a lot.
Not so bad depends on those advertised vs .050" numbers being right? I can't say I've seen any cam profile with lobes that fast. Regardless of the lifter type. Maybe I'm wrong. There's something to be said when measuring mechanical lifter cams.
Duration at 050 Intake: 238
Duration at 050 Exhaust: 240
Duration Intake: 266
Duration Exhaust: 268
A cam card would be ideal. Time to download another Howard's catalogue.
You're right about the comparison to the Thump'r. But this grind looks like circle track stuff.
If that advertised number is right and the intake valve closing is a 55 degrees (IIRC), that'll build a lot of cylinder pressure as the cam behaves short. But the .050" number is high by comparison with plenty of overlap. There's the vacuum deal as pointed out.
Not sure how to take those cam specs.
Not so bad depends on those advertised vs .050" numbers being right? I can't say I've seen any cam profile with lobes that fast. Regardless of the lifter type. Maybe I'm wrong. There's something to be said when measuring mechanical lifter cams.
Duration at 050 Intake: 238
Duration at 050 Exhaust: 240
Duration Intake: 266
Duration Exhaust: 268
A cam card would be ideal. Time to download another Howard's catalogue.
You're right about the comparison to the Thump'r. But this grind looks like circle track stuff.
If that advertised number is right and the intake valve closing is a 55 degrees (IIRC), that'll build a lot of cylinder pressure as the cam behaves short. But the .050" number is high by comparison with plenty of overlap. There's the vacuum deal as pointed out.
Not sure how to take those cam specs.
I just noticed this on hoards website. Might explain a bit
Lift: .510 / .531, Duration @ .050: 238 / 240, Centerline: 102, 305 Sprint Car, Best on tighter short tracks, Strong out of the corners.
Should I ask the Howard's cam guy anything or can anything of use be found on the interwebs?
I went the mechincal as I was told by numerous people that it allows for higher lift while keeping the duration down a bit. No where near a roller, but slightly better.
And all around besides needing to adjust stuff a few times year, they're more reliable.
And as for vacuum, we're either going to go with a canister or manual brakes.
If you are talking to Howard's again, ask about the advertised vs .050" duration numbers.
Even with a mechanical flat tappet and taking into account the valve lash, I can't see how they get from 266 advertised to 238 @ .050" . A hydraulic roller, and this is Comps quickest XFI lobe, will get you from 274(adv.) to 224 (@.050"). I can't say I've seen any quicker than that. (I'm obviously missing something here...)
If you are talking to Howard's again, ask about the advertised vs .050" duration numbers.
Even with a mechanical flat tappet and taking into account the valve lash, I can't see how they get from 266 advertised to 238 @ .050" . A hydraulic roller, and this is Comps quickest XFI lobe, will get you from 274(adv.) to 224 (@.050"). I can't say I've seen any quicker than that. (I'm obviously missing something here...)
I looked around a bit after realizing it was a sprint car camshaft for track racing and number like that are common. Now why howards would recommend it for street use I have no idea.
Haven't been to that part of the catalogue.
It'll be interesting to see the idle vacuum numbers.
I believe the reason they have the super fast ramp rates is because most sprint classes have fairly low max lift regulations so they have to ramp faster to a lower max. Although could be wrong. I would definitively talk to howards about what valve spring to use.
It's all in how the solids are measured. Different lifter rise for the advertised duration will result in a smaller number. Say, .020" as compared to .006"-.008" typically used for hydraulics.
The DCR calculators, using the cam card advertised numbers, don't take that into account. The low advertised number fools the calculator into thinking the cam is very short. This engine will need compression.
I did do some research about it being a camshaft designed for a sprinter car but how does that make it bad for a street car? It's not one that anyone gets, seems like it's almost never been mentioned on any forums before. But is that because it's unknown or because it WILL NOT work good in a street car?
As I said before you really seem dead set on getting this combo so just do it already.
I got one forum that after 8 pages got this build and all agree on it, and howards cams that agrees with it, and I got here where everyone seems to think it's a stupid fart can build that built completely for sound and is going to be a piece of trash on the street.
I get that it's different and that people like to say it's bad, but what are the reasons? Just because it says it's for a sprint car or because it just wont work with a street car??
We won't have power brakes so vacuum wont be an issue.
If people think 230cfm on 200CC is flowing well then they have never seen a good head. My biggest beef with these heads are the lack of info given. He lists his features
Hardened Seats (all heads after 63ish have these)
Bronze Valve Guides (standard)
High Grade Aluminum (really what kind?)
Multi-Angle Seat Design (standard on performance heads but how many angles?)
Available Complete or Bare
Available fully CNC Machined (lets see test numbers)
Designed Performance Valve Springs (Specs, brand?)
Advanced Port Design for Greater Flow (really 200cc 230cfm at 500?)
No specifics just an attractive price instant red flag. I have done the budget head thing and I am still doing it but I have seen a lot of issues over the years. Usually casting errors, pushrod alignment, cheap springs, valve stem wear and cracks on aluminum heads.
I have done the college budget thing and learned the best course of action is to wait another month or two then buy the better thing. BTW speedmaster is just procomp.
Reasons for a different cam, more HP and TQ at lower RPMS with a better idle and less wear on the rotating and valve train components. A little suspension work and some LCARCBs and you can fix a lot of traction issues. I bet that cam sounds almost exactly like a thummper cam but with more valvetrain nose due to being mechanical tappet with a slightly worse powerband.
But you already seem sold so get what you want and enjoy it.
You really should listen to this poster.He knows what he is talking about and do-overs cost double...well sometime more than that.
I got one forum that after 8 pages got this build and all agree on it, and howards cams that agrees with it, and I got here where everyone seems to think it's a stupid fart can build that built completely for sound and is going to be a piece of trash on the street.
I get that it's different and that people like to say it's bad, but what are the reasons? Just because it says it's for a sprint car or because it just wont work with a street car??
We won't have power brakes so vacuum wont be an issue.
Think of how a sprint car runs....then think of street car driving. Will you be doing sprint car runs on the street? Lol
Its alot of duration and a very tight lsa. Its gonna have high overlap and be lazy in alot of the lower end rpms. It might even buck at cruise
A better cam would be something on a 108-110 lsa imo and maybe tiny bit less duration. It will make for a wider powerband and better torque curve
Think of how a sprint car runs....then think of street car driving. Will you be doing sprint car runs on the street? Lol
Its alot of duration and a very tight lsa. Its gonna have high overlap and be lazy in alot of the lower end rpms. It might even buck at cruise
A better cam would be something on a 108-110 lsa imo and maybe tiny bit less duration. It will make for a wider powerband and better torque curve
At this point I just want to see him do it, I have developed a morbid curiosity but don't want to spend the money out of pocket. I bet with those ramp rates the valve train makes some good noise. The springs better be well matched and probably not w/e skip installs. I know the patriot heads I ran the cheap springs they came with and they sucked for my XE274 and I ended up installing some new PBM springs.
Glad to see I'm not the only person who feels this way^^^^^ I have worked at trying to steer the OP to Profiler 185 heads & taking 10* to 15* off the cam duration for uses & power goals,to no avail.LOL.
I agree with above that a set of Vortecs would be a better option,but,unfortunately,with those 4.3cc flat tops,his compression is gonna be a little high.He could probably make it work,but,everything would have to dead spot on for the size cam he needs to run.
10-06-2016, 09:38 AM
Lol. 
