Durability of solid flat tappet cams

[yamadog]

Way back in 1999, Car Craft magazine built an engine based on parts from Joe Sherman Racing. It was a 357 sbc that made 580hp with iron heads and a solid cam (not a roller). Because I have almost no budget for my car, I really liked this motor because they built it for less than 5000$. Now, years later, I have almost all the stuff to assemble this motor. The problem was that the article made no mention of what heads were used other than that they were Dart iron eagles. Those heads are available in several intake runner volumes. So.....I sent an email to Joe Sherman Racing to see if they could help. I was planing on buying the heads from them and having them port the heads also. I also listed all the specs of the motor in case they had no idea what i was talking about. I got an email back from them yesterday stating that a solid cam like that ( Isky 580-a .580/.585 262/266) wouldn't last more than a few thousand miles of street use. They also made no mention of the heads other than "we rarely sell iron heads any more, everyone wants aluminum. Also, build a 383 instead". Not much help. The valve springs spec'd were Isky's also, 150lbs @1.78, 340lbs @1.200. That doesn't seem too over the top for street use to me. Any way, after reading all this, waht is your guy's opinions? Obviously, this motor will be for a PT car (Camaro). I was planning for lots of autocross use. Therefore lots of street miles. Thanks, Jason

[yellow heap]

I think they gave you good advice.
Don't mess with any thing smaller than a 383
I will never ever mess with a flat tappet again.
I see no real reason for iron heads.
The magazine motor was a numbers motor-Crap on the street good in a dedicated race car where it gets freshend up at the end of a season-some dedicated race cars have less than 3000 miles after 40+ years worth of racing seasons.
5000$ can get you a stong 383 + motor if you get the right parts.

[yellow heap]

[yamadog]

Well, like I said I have most of the parts for this motor, including forged 350 crank. Roller cam and lifters is outa my price range.

[shep]

If you look at a newer factory block 87+ you could use factory hydraulic roller. Then use an adapter to adapt the 2 piece rear to a 1 piece. For a 350 between 180 and 200 for runner volume. Some info on flow rates for different heads. http://www.purplesagetradingpost.com...fo/heads1.html If your cam isn't over .500 lift vortec heads flow close to the iron eagles at least according to the cart at that web site.

[alnoe]

I would definately go with a good hydraulic roller-we have several available to go with our heads, and they also work well with other good flowing heads:

www.trickflow.com

I would not recommend running a solid flat tappet cam-they are typically hard on valvetrain parts due to the high spring pressure required, and the cam/lifter setup is not great for street use. I agreee that Sherman gave you good advice.

My old engine was a 388 (4.060 bore) with a small hydraluic roller and our 195 head. It made 485 HP and was extremely streetable-great idle vaccum and it also made really good torque. Big dyno numbers look impressive, but for a street car you want to make good torque and HP. Take a look at the post from Trickflowtech-it has some good stuff on a couple of engine combos we did.

If you have any questions, let me know.
'
Al Noe
Trickflow Specialties

[yamadog]

Ok, here's the thing- I allready have the complete short block, plus the intake. I dont have the heads or the valvetrain. I'm not really able to change the combo at this point. What I was looking for was info from people who have run big solid cams on the street. Surely, I'm not the first to attempt this. This car isn't going to be a daily driver. But I want to autocross it and make runs up the mountain to the lake. The car will have a hyro boost, so vacuum doesn't matter. I LOVE the sound of a motor with a huge lope at idle. And can anyone tell me they wouldn't be impressed with an iron small block running pump gas and making close to 600 horespower? Thanks, Jason

[Tom Nelson]

This will be a good but agressive design to beware I would only use joe gibbs oil designed for flat tappet use.The way to make good torque and horsepower is area under the curve Comp has some xtq intake lobes Pt#6263it's only 286 on the seat but is 256 at .050 they also have a nice ex lobe Xtx Pt number6410 its 292 on the seat but 258 at .050 Make the lobe center 108 install the intake centerline on 104 that should get you close if you have a really nice set of irons.Say flowing260 by 400 and 290 by 580 at 28 inch's with around 10.6 to 1 which will be pushing also on pump if you have an overdrive and run load at low rpm if your above say 2900rpm at cruise you'll be okay .Just remember though this flat tapet won't live all that long i would run Comps new behive set up with there super light weight retainer to reduce some spring tention.Or you could call Good old chet herbert and get one of his solid roller cams and lifters there pretty cheap probally a better bet.Have a good one Tom

[yellow heap]

I love all small blocks 302 and up.
But,600 horse power and a motor that will last= POWER ADDER