1.7 Motorsport roller rockers w/ E303 cam - springs? bind? pushrods? etc.?

Ive had the e303 with crane 1.7 rockers for more than a year now. I have stock springs and stock pushrods, no problems here. But if your already gonna have everything off why not upgrade to a good set of Comp valve springs and hardened pushrods..wouldnt hurt. Piston to valve clearance is good. I thinks its when lift is over .550 when Piston to valve clearance becomes an issue.

No problem

The stock springs are marginal for the stock cam - especially if they're used. If you're serious about using the E with stock heads (I'll come back to that in a minute) and 1.7's, then the springs should DEFINITELY be upgraded. Just because others have run without upgrading does not mean it's the right thing to do. Valve float is the issue.

As for running that cam with your set up -- Crane, who designed the E303 for FRPP (it's identical to Crane's 2040 PowerMax) requires the following changes for that cam:

GOOD MID-RANGE AND STRONG TOP-END POWER, REQUIRES MODIFIED MASS AIRFLOW, AFTERMARKET INTAKE, PERF. CYLINDER HEADS AND HEADERS, MUST USE 5-SPD AND 3.55 OR NUMERICALLY HIGHER REAR GEARS. REQUIRES CRANE SPRINGS AND RETAINERS. (50 STATE LEGAL 85-93, C.A.R.B. E.O. D-225-46) BASIC RPM 2400-6000

Why is everyone wanting to run the E303 cam with 1.7 rockers?

It was designed to run with 1.6 ratio rockers.

Back in the early to mid 90's I ran all kinds of different combos with the "Alphabet Cams", mostly the "B" and "E", and the "E" never responded well with stock heads and 1.7's. It would always run better and faster with the 1.6's.

I also would rather have less of a rocker ratio and let the cam do the work rather than have the rocker do some of the work for lift.

If you want a cam with a certain lift that 1.6's can't give then just get a different cam.

There are many more choices better than the "E" cam out there now IMHO.

Back when I was fooling around with these cams there was not much else out so we didn't have as much of a choice. With all that is out now I DEFINITELY would go with something else.

I also agree with Michael about upgrading the stock springs. The best spring for a cam is one that is matched to that cam's lift and duration, not just "550 Lift Springs" would be OK. If you get a spring rate that is too heavy for what you have then you leave some HP on the table. If you do not have enough spring pressure then you will have problems with valve float as mentioned.

I hope this helps.

bsedwebt70-5.0 said:

thanks - The motor currently has 500miles on a B303 cam with M-6565-L302 Motorsports pushrods, M-6513-A50 Motorsports springs (110lbs closed & 240lbs open single spring), Motorsport roller rockers - factory replacement, etc... all 500miles on them but I did not like the B303 cam so I am ordering an E303 cam, Edelbrock Performer 3821 intake, MAC 70mm t/body & EGR, C&L 76mm MAF w/ 19lb injector rating, 1.7 Motorsports roller rockers, CAI, K&N, MAC equal length shorty headers, flowmaster cat-back exhaust and I am having the heads lightly ported on the exhaust side by removing the "bumps". I am told this will really wake up the low end 0-60mph performance. -- Think the 500 mile springs, pushrods, keepers, etc.. will be good or should I buy new COMP CAMS springs with 120-400 ratings?

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The Motorsport Springs were designed for those cams so you should be OK with leaving them in there. No need to spend more money there with only 500 miles.

You also stated that you have "Motorsport roller rockers - factory replacement". That would mean 1.6 roller rockers. Am I correct? If so you should keep them and not switch to 1.7's and save your money.

The other mods sound like they should work just fine with your combo.

Removing the "Bumps" on your exhaust ports will net you a few HP but don't look for miracles. The other supporting mods will help you more.

I would still look into a different cam choice if I was in your shoes. But if you must stick with that Archaic cam then good luck.

bsed - it's the low end and midrange that will suffer most with that cam choice. If you're serious about low end (look closely at Crane's description of the cam!), I'd stick with the stock cam, or go with one of the stock replacement cams. People seem happy with the 'baby' Crower; look at CompCams' X258 as a stock replacement.

If you insist on the E, a lot of folks say to install it 4 degrees advanced -- that would have the .050" lift intake valve opening at 4 degrees BTDC. Be sure to check p to v clearance -- installing it advanced helps exhaust clearance, but reduces intake clearance -- and it's the intake clearance that's likely to be the closest. This is especially important if you try to stick with stock E7 valve springs which WILL NOT properly control the valve train at higher rpm.

While no two combos are identical, we picked up 45-80 lb-ft from off-idle to 3000 rpm on my mild H/C/I combo when we removed the E cam and installed a mild custom. If bottom end is what you're after, the E with stock heads is not a good choice.

I have a 95 GT with Crane ( E clone), Edel performer rpm 2, trick flow twisted wedge heads, 24 lb injec, Mac shorties, Basani X with 2 chamber flowmasters, 1.6 FR roller rockers, 255 lb hr fuel pump, 3.55 gears. I was thinking about going up to 1.7's to help with lift and see if it would wake up my car's low end torque and hp. I just put a timing chain and fixed TC cover gasket leak and I hate to have to do all of that to change the cam and possibly have to mess with pistons or get new pistons right now. I am basically trying to work with what I have and doing the rocker arms I can probably do that myself. What are you guys thoughts with my setup and the 1.7's helping or not, and how much can I expect to gain?

You will LOSE your low end with that change. The gain (if any) would be top end.

bsedwebt70-5.0 said:

thanks - The motor currently has 500miles on a B303 cam with M-6565-L302 Motorsports pushrods, M-6513-A50 Motorsports springs (110lbs closed & 240lbs open single spring), Motorsport roller rockers - factory replacement, etc... all 500miles on them but I did not like the B303 cam so I am ordering an E303 cam, Edelbrock Performer 3821 intake, MAC 70mm t/body & EGR, C&L 76mm MAF w/ 19lb injector rating, 1.7 Motorsports roller rockers, CAI, K&N, MAC equal length shorty headers, flowmaster cat-back exhaust and I am having the heads lightly ported on the exhaust side by removing the "bumps". I am told this will really wake up the low end 0-60mph performance. -- Think the 500 mile springs, pushrods, keepers, etc.. will be good or should I buy new COMP CAMS springs with 120-400 ratings?

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I don't mean to be an A$$ here but I don't know what youtube sound clip you heard or what sparked your interest in a "E" cam as a replacement for what you have. As stated above the "Alphabet" cams are no longer your best bang for the buck. If they ever were. Call a cam manufacturer with your info and let them pick you one. The technology has changed enough that you can get a split duration cam that will perform much better. Don't be the guy at the car show telling everyone he has a "three quarter race cam"....or "E" cam, just because it sounds good. Be the guy who they ask at the track "wow what cam are you running? that thing's fast"

gearheadboy said:

You will LOSE your low end with that change. The gain (if any) would be top end.

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I certainly right now am trying to gain some low end hp and torques. I know my heads and intake are starving for a bigger cam but I was hoping going from .498 to bout .529 would give me at least 20 hp. I just fixed the TC gasket leak and put in a new chain a few months ago and man ole man not sure I want a new cam at this point or wana go that route just yet when I know I will make changes when I need to rebuild. I might just get a retune or let them check my A/F ratio and do some checks and tell me rather a new tune will help me out at all. I got my car tuned in 2005 with an autologic 2000 chip which no one is doing any longer. I think there was an issue with my MAF that I possibly had recalibrated after the tune. According to my book, I got the maf recalibrated from 19's to 24's before the tune so I should be fine in that regard but I don't think that tune still came out right. I think now with all of the checks and stuff , cleaning stuff, tuning up, ect I think a new tune would be better overall but once again I dont just wana shell out 500 bucks and not be happy. I want them to let me know what can be done possibly first and what to expect even if it cost me a little money for them to check some stuff and tell me that information.

And yeah back in 02 when doing engine swap and wanting a cam, I didnt know anything about them and if I would have known 10 yrs later I would be wanting another better one I would have done so from start. Thats why my next moves will be geared towards future even though car is a weekend driver non race or track car. I just play around a little sometimes when I'm in the mood