Okey i am running a 400m with the crane 272 cam but without the maching springs but i was thinking about changing the cam and valvetrain maby with the compcams K-kit... i was thinking about the 274 Extreme cam would that be a good change?

 

Just guessing on compression? Need to be in the 9.2 to 9.5 compression. what tranny? Manual or auto?

 

The truck has a manual transmission 1. gear extra low ... im nott sure about the compression the engine is bored 0.30 over with forged trw pistons (stokk compression 8.2:1) the blokk dekked 0.25 and heads milled 2.0mm also the heads been ported (mached to the manifolds) i just resantly innstalled a knew dui distributator and a 750 edelbrock carb with 2% lean calibration ....

 

Here's the problem as I see it.....

1. Comp has by appearance - seems to be a company that has experience more cam lobe failures than most and places the blame on the low ZDDP in the oils. Is it a factor yes, but I highly suspect that they are also using Chinese cam billets & they do not include Parkerizing their cams (Parkerizing is the final step and a crucial step (IMHO) to help break the cam in- a heated acid bath that microscopically etches the metal surface and adds a very thin layer of graphite coating which allows the cam lube to hang onto and penetrate into the cam surface during cam break in) unless you specifically request and pay additional money for it.

2. Considering the cam has such critical importance to the engines performance and life, to me it makes sense to use a cam grinder who will talk with you directly- even modify the cam grind to fit your needs even better and to address the possibility of cam lobe failure with the new oils. With regards to price...the difference is nil- especially considering its cheap insurance to know exactly who is machining such a critical part for your engine. And remember, advertized lift/duration/lobe separation is just that- advertized and not the specific grind including ramp profile that is used on the cam.

That is why I highly recommend Iskenderian & Crower...both are family owned, been grinding cams for decades, and both will even re-grind your oem cam if possible- saving you even more $.

As you are probably aware, many of the cam mfgs in the past few years either sold, closed their operations to re-open elsewhere (typically with new staff) or .......

In addition to Isky & Crower, I use to very highly recommend....
Sig Erson & Crane...

Both became part of corporate entities, eventually leading to periodic quality issues and closing their doors- I think Crane re-opened, but with a different staff. Typically the staff is very, very young and well- requires a learning curve.

If you do a search on the net, Harvey Crane has posted a little summary of the history of the people who made the cams at Crane, his opinion of what happened and the eventual outcome of several of the staff.

Given the criticality of the component- IMHO, I don't like speaking to a catalog parts sale person- they really don't know any more about the cam than what they are reading, when it comes to making an engine breathe, there are so many variable including elevation, humidity, fuel blends/available octane, most cam mfgs will vary a "core grind pattern" to match the external impactors in addition to the internal impactors- which today IMHO makes the different between and engine that runs well, to one that just seems to run a little bit better, smoother and gets better mileage than expected.

 

750 cfm carb but the lean condition you say its setup for is in question. So I say jet it up and see what happens. do a 2 step jump up and see if motor wakes up. If a 70 jet in carb move to 72 jet. what is the timing?

 

okey i cant find my specks on the carb the jets were 104 but i dont remember wich roads are in it .... but the engine runs real strong but i think it has the stock valve springs just with hardened pushroads but i set the timing on 12 BTDC but im wandering what my compression ratio might be ?? did a compression check with all spark plugs removed and the throttle wide open and it read a 165 psi on the engine cold ......

 

ran many edelbrocks and never could get them to do what I want. So I tend to not waste my time with them. They run OK but are mainly a good driver carb. Nobody wins at the track with a edelbrock! If you set up lean you set up for minimum performance! meaning lacking in something. On the 274 comp cam I think thats a little big for a daily driver/weekend warrior. You will notice your btm end torque will begin to change/go away. Ran the 274 before and need to make sure your springs will work, you will coil bind cylinder heads with stock springs!! Your compression is decent but that cam will probably want around 9.5 to 10.0 comp if you don't it will feel kinda soggy in the beginning and come on later. depending on stall converter or slipping the clutch a little. Whats your tire/gearing? Your cam can change your compression by the intake valve opening/closing and bigger cams open later meaning blowing down the cylinder more. Meaning blowing down cylinder pressure means loss of low end torque. I don't run the comp cams anymore and only use www.mpgheads.com for my cams. Scott is a ford guy you need to know about and has done great work for many yrs for me. He cuts his own cams and many other things. If you call give him your situation and he will cut you a cam to your application. Comp will do a good job but the zinc will be a requirement for startup. catch you later.

 

In the past I was paid money to pick cams for people. so trust me on this.
If the cam you have now seems to work fine for you why are you chaging to something that looks to be almost identical??
just get the spring kit and degree in the cam. you can advace the cam slightly to get better low end or retard it if you want a littele more up top.
However take a compression test to see where you are on your compression. advacing it will raise your numbers and retading it will drop them a litte bit aswell.

 

okey thanks fore the advise the gear ratio is 4:10 to 1 and the tires are 38" radial mudders .... this is a weri ligth truck just about 2. tonns with fuel ..

 

AGREE!!!!!

 

manual can work around. I run 38" and 39" and run a 4.56 gearing with lowgear kit in c-6. One of the biggest problems I ran into was killing converters. buring up my stators and trashing my converter and tranny. Got the automatic figured out now. I also run a manual shift tranny auto setup. I run some decent hrspwr so these factors do come into play with big block. The 400 should be OK with manual what clutch? 11" or 12" used to run a centerforce. I have split several cases NP435 and dropped out lower shaft in case. Miss shift in racing application. I just happen to be familiar with your setup and tire size my blue truck has 40" hawgs on it but they are actually 39" and I run 38" bogger also depending on situation. hawgs last long time and boggers short life but I love my boggers!!

 

okey hehe im not sure about the cluts but radial mudders work veri well in the snow with about 5-2 psi tire pressure and 15x15" rims and in the lowest gear but then i was thinking about piston change to get about 10:1 compression and keep the cam i have just install knew springs