Wicked

I'm wanting to change my 383 to a solid roller this month, have a few questions.

1. I'd like to relocate my alternator to allow easier access to the valve covers, who sells a kit for this?

2. What Stud gurdle can I use that works with center bolt valve covers?

3. How much of a difference in 1/4 mile time do you think is between a Nitrous Cam vs. Motor cam? I've heard it's a lot, but kinda want an idea I guess. I built my motor the first time for nitrous and was pretty unhappy with it's performance on motor.(12.0s@114) I want to hit mid to low 11's on motor then put a 400 shot on top of that.

4. Shaft mounted rockers? Are there any for centerbolt LT1s? If so who sells um and is this a route I should consider? If I go with these, do I still need taller valve covers?

5. I'm worried about running into clearance issues with a new cam with bigger specs. Would like to go with a smaller base circle, but then I worry about clearnace issues w/ the lifters in the lifter valley. Any taller lifters that can take care of this? -comp cams said use 871 lifters said will be fine even if I run a .900 base circle cam. so guess clearance isn't a big deal-

Thanks and any other tips here would be very benifical!

Jason Fetter

Wicked

I get a different answer every time I call comp cams so... What cam should I go with. This car is 90% Race car 10% street car. Most I ever intend to drive the car is to work once in a while(8miles) and street races etc.. Max I'd drive it is like 30 miles maybe a tad more.

I'm going to upgrade my convertor to a 5k stall.

Cam 1: 254/256 621/637 114LS

Cam2: 260/266 627/637 110LS

Cam3: What do you think?

The guy I just talked to said don't go with the 110 because of the amount of nitrous I plan to run (400 shot).

Also, read the post earlier about the 943 Springs.. any machining need to be done w/ the heads to get these to work? He recommeneded 939's.

Jason

OldSStroker

You might get more responses by posting inthe LT1 Tech Forum.
Searching that forum for 383 engine buildups might also help.

Who is designing/building your engine? Ask them.

With limited information about head flow, etc, free cam advice is worth just what you pay for it. Perhaps that's why you get so many different responses.

Good luck.

rskrause

400hp nitrous shot? To heck with worrying about the cam. How you gonna stage the N2O and keep the motor together when you spray? If you do plan to use a 400hp nitrous shot, you had better have great exhaust ports and a cam with a huge "split": the exhaust duration is going to have to be quite large compared to the intake. It's very hard to be specific without more info, and besides, I don't know of anyone "here' with experience with monster nitrous motors.

The Old Stroker has a good point. If you are building something that radical maybe you need some professional advice.

Rich Krause

kmook

I also agree on the Prof Advise comments. You dont want to be runnning a cam that Comp recomends in an engine like this, you want to run a cam that someone that knows what their talking about recomends (sorry comp is horrible with cam recomendations).

Nonetheless, all these questions are suited for LT1 Tech. Moving there.

Mad Machinist

1. Mad Man Racing and More Performance I believe

2. Moroso makes one

3. How fast do you want to go. More NA or more nitrous? You can be milder with the nitrous-bias setup or more radical and NA-bias. Personal preference really.

4. The rocker stands won't interfere with the centerbolt setup. Suppliers: Yella Terra, Comp, Jesel, T&D.

5. I don't follow you on the clearance issues. The reduced BC is for rod/cam clearance. Either way, it is likely to be a problem with an aggressive cam in this stroker

Personally, I would prefer the second cam choice over the first because I would rather be quicker NA. That cam compromises nitrous performance but with some advance ground in, you are still exhaust biased. I would also like to see about four degrees more exhaust duration. I don't have a problem with the 110 lda though as I have used cams with similar specs with very good results.

Mike

thewinner

do not use compcams tech line, hell dont even go with comp. bunch of dicks imo. they recommended a cam similar to stock for a 383....

Mad Machinist

Comp Cams likely gets a million tech calls a day. Unless you know someone at CC, you are unlikely to get a "great" cam suggestion.

While I like many of CC's lobes, especially their RT series lobes, you will get more personalized service working through a company like Ultradyne, Cam Motion, Schneider...
Either that or you work through an engine builder who has connections through a cam company. The "pay" part.

Mike

rskrause

Do not rely on the "Tech Line" from Comp or any large company for personalized advice about your combo. The people who answer the phone lack the knowledge to help you. They do not put their chief engineer on the phones! If you have a specific question related to a technical aspect of the product, you do have a fair chance of an accurate answer. Example: do not ask "what cam is best for my application". The answer is almost certain to be useless. OTOH, if you ask "can lobe 'x' and lobe 'y' be ground on core 'z' with a 'xxx' LSA", you will probably get a useful answer. They usually (not always) know their own products a lot better than they know cars in general or certainly more than your specific car.

You will do better with a knowlegable retail vendor. But as far as cams go, many of you guys seem to always be looking for the best price. This is understandable, but keep in mind that the prices many retailers charge for cams leaves maybe a $10-30 profit. Don't think you are generally going to get more than a couple of dollars advice on a purchase with a $10-30 profit! The vendor will go out of business quick if they consistently provide a product at a loss. They may spend a lot of time with you hoping to sell you other stuff, but in general you will get very generic advice. This is fine for many combos, as they are pretty generic.

For a project like this, you need more than generic advice if you want to optimize the results. If you deal with a high level performance shop, you will probably get good advice but the cam will cost you more, it's a fact of life. We do "custom" cams for people at the shop I am associated with and charge ~$75 more than the cam costs us. It can take a good 1/2 hours of talking with the customer and working up some sims, looking in catalogs, etc. to make a recommendation. So it's not a huge profit for the amount of time invested, the overhead, etc. And these are not true "customs", of course. They are "Chinese Restaurant" customs, one lobe from column A, one from column B, etc. If it's a true "custom" the cam will be very expensive to grind and you will need somebody very sophisticated to spec it out, which will also cost money.

Rich Krause

Wicked

I can totally understand going through an engine builder to get the cam. I really don't want to go through the place the built my motor because I just don't trust they know wtf they are doing to LT1s.

Who do you recommend I can call to get the advise I need?

-Also can I get a web site or phone # w/ the name if possible-

As far as the engine, it's built pretty solid and I guarntee the bottom half will hold what I want it to. 400hp shot of nitrous shouldn't be a problem at all. Just a matter of getting the right tuning etc, and dont know who to go to.

Thanks,
Jason

thewinner

do you realize how much stress 400 shot of juice is gonna put on that motor? IMO that motor will need to come out often and be refreshed, etc.

rskrause

Look at http://www.kennedysdynotune.com/ and click on the "Custom Cams" button on the left hand menu. Most likely, Bob will answer the phone. Mention that you talked to me and that I have a good idea of what you want. Most cams are $350. The difference in price between an off the shelf grind from a parts house is the time taken to select what will work best for you. Most of the cams we spec out are from Comp due to fast service, good quality, and large "lobe library". We can sell you the springs, retainers, etc. that you need as well.

Rich Krause

Wicked

yeah, I understand that it's gonna take a beating. I knew that going into it. I want to get my car in the 8's so it is what it is.

Jason

Wicked

Will give them a call Thursday, thanks!

Jason

Jeff Belloma

engine dyno experience and a familiarity with certain setups will get you close by choosing a lobe from a list. that's all good and fine but you need computer modeling and an experienced operator to get close to optimum for your intent. not everyone can do that, but the difference could be as much as 5% in average output. that isn't had by choosing the lobe by what is readily apparent (duration, lsa, lift) but by choosing a cam with the right opening and closing points for the application.

if you can get in touch with dennis oschle at reed cams, he's very knowledgable. same story with harold brookshire at ultradyne. see what they have to say.

JB