Making a Clevo really REV! - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

TTNOS8 · 12-08-2003, 15:09

Just finished putting together a fairly hot 351C, balanced, flat tops, good heads, redline manifold, 750SQ DP, etc etc, and am about to start building another engine piece by piece.

Since i'm going to be bulding it slowly over the next year, I really want to build something that is going to rev like crazy, yet still make plenty of power through the mid-range.

The main thing I want to find out is how to make the bottom ends safe and strong for up to around 7500rpm.

What are the main things to do to a clevo bottom end to help them cope with this kinda revs?

I've already started knive-edging and rubbing back the crank, and will have it balanced well, i've also bought a main-cap girdle to help the bottom end.

Almongst other things I plan on doing to the engine, what will keep the bottom end strong for up to 8000rpm rev bursts?

Thanks

brenx · 12-08-2003, 16:53

What rods are you running? I've had my 351 rods to 8500rpm but honestly I wouldn't do it on a regular basis.

I've been told by various cleveland builders that:

a 351 rod will do 7000rpm safely when prep'd,
a 302 rod will do 7500rpm safely when prep'd.

Just make sure it's all balanced properly, down to the gram. Otherwise it'll go bang. Yes, measure the machinists work as some are pretty rough, even though it looks good.

Brenden

Racer · 12-08-2003, 19:12

Oil restrictors and a solid cam would be mandatory. The oil restrictors (which fit into the mains) restrict oil flow to the top end of the engine and keep it down the bottom where it is needed most.

RevHeadRon · 12-09-2003, 01:09

wouldn't it be an idea to look into changing the clearances (making them closer) in the bearings and running a thinner oil? you could do that and restrict the oil flow to the top end

Supa R00 · 12-09-2003, 02:47

You must fully balance and machine etc every thing in the bottom end to make it rev that hard... it'll make the engine

TTNOS8 · 12-09-2003, 13:54

Brenx: I have both 351 and 302 rods. I am going to use the 302 rods for better rod geometery, increased TDC time, easier revability, etc, etc.

I will be balancing most of the engine myself to make sure everything is spot on.

Racer: I will definetly be running a solid, and I was looking at changing the oiling system, so as to not require restrictors in the bottom end, as RevHeadRon said, mainly with revised oil pump, different pressures, big sump and deburred top end/block.

Supa R00: I realize it must be balanced extremely well, but what I'm trying to find out is all the other aspects of keeping it together well.

Anyone used or looked into using or know about main cap girdles?

Std, 4MA, 4MAB?

4 bolt caps? either std or redrilled?

tunnel boring, deck heights, etc a must?

Thanks everyone. :)

qwikcorty · 12-09-2003, 21:32

to make it rev, why not de-stroke it? or use a 302 crank? ive seen a de-stroked 351 b4 somewhere.

TTNOS8 · 12-09-2003, 21:59

de-stroke?

me non comprahende. understand no.

Naa, I'd like to stick with as much cubes as I could. considered a 377 or so stroker, but it kinda went against my original plan of strength and revability.

wouldn't using a 302 crank make it a 302? is is that what you are calling a destroked 351. otherwise know as a 302.

qwikcorty · 12-09-2003, 22:04

nah de stroked as in a 351 crank turned into a 330 or 320
but wound a 302 crank love to rev alot better than a 351? 3 inch stroke compared to a 3.5, and longer rods again, could maybe go longer than stock 302 rods.

Soxx · 12-09-2003, 22:38

Some Pro Stock drag Clevelands used to de-stroke them, but they were also revving to almost 10,000rpm.
8000rpm is really a practical limit for a road going engine, with your limit of 7500rpm being more sensible.
You will also need a decent explosion proof harmonic balancer and a steel flywheel, I would also use 4 bolt mains and have it tunnel bored.
Any of the cranks will do, some say the 4MAB's are the best, but in reality there is not much difference between them.
6" rods are mandatory.
A bulletproof oil pump drive.
The others have already mentioned most of the other stuff.

Rick.