[montyv8]

hey guys, got a few questions. in my shed i have:
2 complete 302's, both out of XD/E's. (electronic dizzy etc)
1 complete 351, not sure what it was in, but its pre-XC.

i want to build a reasonable 351 for the xb coupe i pick up in three weeks.
heres the basic package:
late block
351 crank and rods
standard size 351 pistons, maybe 30 thou o/size
closed chamber 2v heads with standard size valves
standard electronic distributor
edelbrock perfomer or similar manifold
pacemaker tri-y extractors
650dp holley
not sure on cam yet

fairly basic huh? can i drop the closed chamber heads straight onto the 351 without any probs?
i'll be running a c4 and 3.5:1 9inch. the car will be used mainly for weekend cruising, and the odd run down the track for a laugh. will not be used for daily driving at all. what size stall converter should i use?
i've probably missed out heaps. if anyone has any suggestions, they're more than welcome. sorry about the long post guys.
cheers, Phil

 

[russxr67]

the closed chamber heads will yield way too much comp with pump gas unless you are prepared too either hog the chambers out or use a dish type piston.can you be a little more specific on cam? solid ,hydraulic, rpm range etc ,then we can give more specific details.

 

[falcon coupe]

Use tri-y for bottom end, use 4 into 1 if you want it to rev hard, stall convertor should be matched to your cam profile, so it comes in just as the cam is starting to work in it`s intended rev range.
Is the bottom end going to be standard or balanced ? no point going to mad up top if the bottom wont handle it.

 

[xr8_sprint]

very similar specs to my old motor...

in a XB with things done right you can expect to be in the 13's for sure.

enough to keep alot of v8s out there honest... Alot of room for improvement with that motor (ACL Race series pistons, 6" 302 Rod with ARP bolts, work the 2V heads, weiand manifold, DP carb.. the block/crank/heads are capable of 450+HP).

shane

shane

 

[montyv8]

i've never had a car with a hi-stall before, so wasn't sure what stall to fit, and the cam profile i'd need for it. rev range would probably be 2000-5000 i guess. i usually play around with manuals so not sure on the whole auto scene. but, like i said, it'll mainly be for cruising, with a bit of an occasional thrash.
the crank etc will be balanced.
what are the pro's and con's of the two different types of cams?

 

[STROKEXD]

hey guys, got a few questions. in my shed i have:
2 complete 302's, both out of XD/E's. (electronic dizzy etc)
1 complete 351, not sure what it was in, but its pre-XC.

i want to build a reasonable 351 for the xb coupe i pick up in three weeks.
heres the basic package:
late block
351 crank and rods
standard size 351 pistons, maybe 30 thou o/size
closed chamber 2v heads with standard size valves
standard electronic distributor
edelbrock perfomer or similar manifold
pacemaker tri-y extractors
650dp holley
not sure on cam yet

fairly basic huh? can i drop the closed chamber heads straight onto the 351 without any probs?
i'll be running a c4 and 3.5:1 9inch. the car will be used mainly for weekend cruising, and the odd run down the track for a laugh. will not be used for daily driving at all. what size stall converter should i use?
i've probably missed out heaps. if anyone has any suggestions, they're more than welcome. sorry about the long post guys.
cheers, Phil

MontyV8 as you described it that would make a great sensible combination, with the right cam will be a good torque producer. Someone else said it would do 13's, doubt that very much with near standard heads and a street hydraulic cam.

Keep the cam reasonable, suggest a small hydraulic, the 302 heads work great - I've tried it that way. Get the heads releaved and use flat tops rather than dished pistons to get it down to 10:1 thereabouts.

That sort of combo will work well with standard gearing or only slightly higher than standard.

 

[STROKEXD]

i've never had a car with a hi-stall before, so wasn't sure what stall to fit, and the cam profile i'd need for it. rev range would probably be 2000-5000 i guess. i usually play around with manuals so not sure on the whole auto scene. but, like i said, it'll mainly be for cruising, with a bit of an occasional thrash.
the crank etc will be balanced.
what are the pro's and con's of the two different types of cams?

PS Keep the cam small enough so you don't need a high stall, waste of torque if you don't need it.

 

[montyv8]

i was thinking about getting the heads ported and polished to, as i know somewhere i can get a good job done for a good price.
should i use 302 rods in the combo i suggested and acl or similar pistons to suit? i recall hearing somewhere something along those lines, 351 crank, 302 rods and "boss" pistons.

 

[STROKEXD]

In my view the 302 rod option will be an additional cost that won't make a scrap of difference in your situation.

 

[ford4v429]

If youre replacing parts, I'd sure go with longest rods you can stuff in it...heres a link to some good info on effects of rod length/stroke ratios:

http://www.victorylibrary.com/mopar/rod-tech-c.htm

and another link that tells stroke/rodlength for just about every standard motor out there at a glance(note how high the ratio is on the ford429, and the 426 hemi chrysler- the highest ratios in anything over 400 cubes, and a couple of the best racing engines ever built for nascar):

http://users.erols.com/srweiss/tablersn.htm

do yourselves a favor, read thru that first site thoroughly- very interesting stuff, and a lot more than the simple sidethrust issue that always worried me on strokers...timing, detonation, lots more related than I ever thought about...

 

[Work Horse]

Montyv8 my 2 cents worth, you have said Streeter so

-What you mentioned in your original post sound good to me

-302 rods no advantage in your situation

-P&P 302 heads great, just be sure to check comp. ratio, any engine shop can do this for you

-A Vacum Sec carb will work better on the street with an auto over a D/P

- Highstall convertor speed depends on your cam, stay with something small

-forget about a soild cam

-I use 214/[email protected] cam and 2100rpm stall in my XD, with tri-ys p&p 302 heads performer manifold 600 Vac sec and 3.23 gears.

-I have run [email protected], no drag car but will see off most standard cars

-I can tow a 1.5 tonne of mini excarvator through peakhour traffic on a 30c+ day and not over heat

 

[XW PHIL]

I'm thinking of building a 351 using a 302. I've been told to just put in a 351 crank and change the cam, this will boost the compression ratio to about 10.5:1. I'll have to use high octane, which I intend to do anyway but I don't really know if this works.

 

[brenx]

I'm thinking of building a 351 using a 302. I've been told to just put in a 351 crank and change the cam, this will boost the compression ratio to about 10.5:1. I'll have to use high octane, which I intend to do anyway but I don't really know if this works.

In regards to the high-stall. With 3.5's I'd stick around the 2500rpm mark and engine wise a cam that comes in around 2200rpm. If you had 3.7's. I'd suggest a 3000rpm convertor. If you haven't got a trans cooler? I can recommend the B&M pn:70265 race coolers. It'll keep the auto nice and cool.

Other than that the combo looks/sounds good. 351 with 302 rods isn't an issue. Your pretty much on your way to 400hp. 10.5:1 with 302 closed chamber heads with a hydraulic cam I've seen ping. Make sure the dizzy is right. XBWGN's engine runs 10.5:1, 302 closed chambers, with a Crane F238 and it's pinging it's arse off. The prior engine @ 10:1 had no detonation issues and made 212rwkw.

Brenden

 

[shaynet]

I'm thinking of building a 351 using a 302. I've been told to just put in a 351 crank and change the cam, this will boost the compression ratio to about 10.5:1. I'll have to use high octane, which I intend to do anyway but I don't really know if this works.

XW Phil,
You can't just drop a 351 crank into a 302. The 302 rods are longer(than a 351's) which means that you will spend a long time digging your 302 pistons out of the heads.

You need special stubby pistons to suit which means getting the old pistons pressed off the rods and new ones pressed on, new rings to suit and a rebore and hone for the new pistons. The 302 rod with 351 crank combo usually results in zero deck height and therefore higher compression than you had before so you will probably need to get the heads relieved or put up with the pinging which will ultimately destroy the engine.

If you change the cam you will need new lifters.

Unless you were planning pretty much a complete rebuild you can see a lot of expense coming your way. Mind you it would be worth it if you want a tough street combo. While your at it ditch the cast heads and get a set of nice alloys from AFD

 

[brenx]

Unless you were planning pretty much a complete rebuild you can see a lot of expense coming your way. Mind you it would be worth it if you want a tough street combo. While your at it ditch the cast heads and get a set of nice alloys from AFD

From what I'd gather is he's is planning a full rebuild anyway. The engine builder/parts supplier would pick up on the pisons. From the parts being listed I am gathering alloys are out of the picture budget wise. It looks like a budget rebuild. $3200 for a set of heads + guides + screw in studs + roller rockers aint exactly $3200 anymore. It's the best part of $4000-$4500. Word from the wise. Don't go spending big $ on cast heads. My old 2V's cost $3700 complete 3 years ago. It wasn't worth it. So if the rebuild on the 2V's is large? Go alloys for a very few $ more. I am very pleased with what the engines doing with alloy heads.

The combo looks like it'll be a decent setup using hydraulic cam, so no rollers etc needed. Which keeps the budget looking good. Alloy heads need rollers regardless of whether the cams hyd or not. More $$$.

Brenden

 

[XW PHIL]

Thanks for the tips. Yes it's a full rebuild, but on a budget. I'm rebuilding it myself and I'm lucky to know an engine machiner to get the virgin bore block taken out about .020" and get the heads machined. I intend to smooth the heads out in the ports and clean up the chambers to prevent any pre-detonation, smooth the top of the block where the manifold sits (help with oil flow), chamfer the oil ports (assist with oil flow again).

As for the rockers, I was going to get roller rockers but if I don't have to then that'll save me a heap of money. I'm only looking for about 300hp, any more than that and it's a bonus. The car's only going to be used as a tourer and I intend to drive it from Sydney to Melbourne/Adelaide etc. The family is going to be with me, so I'm definately not after something to hit 11 sec's in the 1/4. 13's + is okay.

 

[slaves wage]

Work horse speaks truth

Many others speak with forked tongue